0.5 FIELDIANA Geology NEW SERIES, NO. 38 The Status of the Sauropterygian Reptile Genera Ceresiosaurus, Lariosaurus, and Silvestrosaurus from the Middle Triassic of Europe Olivier Rieppel February 27, 1998 Publication 1490 PUBLISHED BY FIELD MUSEUM OF NATURAL HISTORY for Contributors to Fieldiana General: FielarAntrV! primarily a journal for Field Museum staff members and research associates, although manuscripts from nonaffiliated authors may be considered as space permits. The Journal carries a page charge of $65.00 per printed page or fraction thereof. Payment of at least 50% of page charges qualifies a paper for expedited processing, which reduces the publication time. Contributions from staff, research associates, and invited authors will be considered for publication regardless of ability to pay page charges, however, the full charge is mandatory for nonaffiliated authors of unsolicited manuscripts. 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Author-generated changes in page proofs can only be made if the author agrees in advance to pay for them. © This paper meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper). KOL08V LIBRARY FIELDIANA Geology NEW SERIES, NO. 38 The Status of the Sauropterygian Reptile Genera Ceresiosaurus, Lariosaurus, and Silvestrosaurus from the Middle Triassic of Europe Olivier Rieppel Department of Geology Field Museum of Natural History Roosevelt Road at Lake Shore Drive Chicago, Illinois 60605-2496 U.S.A. Accepted January 7, 1997 Published February 27, 1998 Publication 1490 PUBLISHED BY FIELD MUSEUM OF NATURAL HISTORY • * -•;»■'■'-•• ; ■"•■■■■■ "•«•:•■ © 1998 Field Museum of Natural History ISSN 0096-2651 PRINTED IN THE UNITED STATES OF AMERICA c 3d Table of Contents UBRKRTD.tJFl Abstract 1 zusammenfassung 1 Introduction 1 Materials and Methods 2 The Stratigraphic and Geographic Dis- tribution of Lariosaurus 3 Previous Cladistic Analyses of Lario- saur Interrelationships 9 Character Analysis 10 General Morphology 10 The Skull 12 Postcranial Skeleton 15 Discussion 22 A Case for Monophyly 23 Systematic Paleontology 27 Evolution and Paleobiogeography of the Genus Lariosaurus 37 Acknowledgments 39 Literature Cited 40 Appendix I: Character Definitions 43 Appendix II: Material Included in the Analysis 46 UKBAflA-CHMAPNBI 6. Lariosaurus balsami (original of Ticli, 1984) 7 7. Lariosaurus balsami (original of Ticli, 1984) 7 8. Lariosaurus balsami (original of Re- nesto, 1993) 8 9. Holotype of Proneusticosaurus carin- thacus 8 10. Skull of Lariosaurus 12 11. Skull of Lariosaurus curionii n. sp 13 12. Sacrum and hind limb of Lariosaurus ... 16 1 3. Pectoral girdle of Lariosaurus 17 14. Left forelimb of Lariosaurus 18 15. Humerus of Lariosaurus 19 16. Forelimb and hind limb of Lariosaurus .. 20 17. Left zeugopodium and carpus of Lario- saurus calcagnii 20 18. Manus and pes of Lariosaurus balsami .. 21 19. Strict consensus tree indicating lario- saur interrelationships 23 20. Strict consensus and majority rule con- sensus trees indicating lariosaur interre- lationships 25 2 1 . Paleogeography of Sauropterygia 38 List of Illustrations 1. Locality map 3 2. Stratigraphic distribution of Lariosau- rus 4 3 . Holotype of Lariosaurus balsami 5 4. Lariosaurus balsami (original of Bou- lenger, 1898) 5 5. Lariosaurus balsami (original of Mari- ani, 1923) 6 List of Tables 1 . Proportions of the ulna in Lariosaurus .... 20 2. Number of carpal and tarsal ossifications in relation to body size in Lariosaurus .... 22 3. Data matrix for the analysis of lariosaur interrelationships 24-36 in The Status of the Sauropterygian Reptile Genera Ceresiosaurus, Lariosaurus, and Silvestrosaurus from the Middle Triassic of Europe Olivier Rieppel Abstract The geographic and stratigraphic occurrence of the Middle Triassic sauropterygian genera Ceresiosaurus, Lariosaurus, and Silvestrosaurus is summarized, and their skeletal morphology is critically reviewed. A cladistic analysis using parsimony supports the synonymy of all three genera, among which Lariosaurus takes priority. The genus Lariosaurus includes five species, balsami, buzzii, calcagnii, curionii n. sp., and valceresii, with only partially resolved interre- lationships. The sister group of Lariosaurus is the genus Nothosaurus. Lariosaurs diversified during Ladinian times in the northwestern Tethyan coastal area, after the genus Nothosaurus had invaded the Alpine intraplatform basin facies. Zusammenfassung Die geographische und stratigraphische Verbreitung der Gattungen Ceresiosaurus, Lariosau- rus, und Silvestrosaurus wird zusammengefasst, und die Morphologie ihrer Vertreter kritisch diskutiert. Eine kladistische Analyse stiitzt die Synonymie aller drei Gattungen, von welchen Lariosaurus Prioritat hat. Innerhalb der Gattung Lariosaurus werden ftinf Arten unterschieden: balsami, buzzii, calcagnii, curionii n. sp., und valceresii. Schwestergruppe der Gattung La- riosaurus ist die Gattung Nothosaurus. Die Lariosaurier diversifizierten wahrend des Ladins im nordwestlichen Kustenbereich der Tethys, nachdem die Gattung Nothosaurus in die Alpine Fazies vorgedrungen war. Introduction Lariosaurus balsami Curioni, 1847, ranks among the earliest fossil reptiles described from the Middle Triassic of the southern Alps. The ho- lotype from the black shales of Perledo in north- ern Italy was originally described and figured by Balsamo-Crivelli (1839) as a representative of the "famiglia dei Paleosauri." Curioni (1847) de- scribed a second, distinctly smaller specimen from the same deposits as "Macromirosaurus Plinf (etymologically correctly spelled as Macromero- saurus by Cornalia [1854] and most later authors, including Curioni [1863]), and formally named Balsamo-Crivelli's specimen Lariosaurus balsa- mi. Although the name Macromirosaurus (Mac- romerosaurus) suggests a relatively large humer- us, Curioni (1847, p. 161) noted that femur length exceeded humerus length by almost 30% ("magg- iore di quasi una terza parte"; actual measure- ments on the holotype of Macromirosaurus plinii indicate that humerus length is 86.8% of the fe- mur length). This feature was believed to distin- guish Macromirosaurus from similar specimens, one from Perledo, with a humerus longer than the femur, the other from Viggiu (Varese, northern It- aly), with humerus and femur of approximately equal length. The controversy (see Rieppel, 1987, for a detailed account and further references), which unfolded with the description by Cornalia (1854) and Curioni (1863) of additional speci- mens from Middle Triassic black shales of north- FTELDIANA: GEOLOGY, N.S., NO. 38, FEBRUARY 27, 1998, PP. 1^6 ern Italy (Viggiu and Besano), highlighted the problem faced by these earlier authors in distin- guishing Lariosaurus and Macromirosaurus from pachypleurosaurs {Neusticosaurus [Pachypleuro- saurus] edwardsii; Sander, 1989), and culminated in Curioni's (1863, p. 266) claim that all fossil saurians from Perledo had to be referred to a sin- gle taxon, Lariosaurus balsami. By implication, Curioni (1863) accepted Macromirosaurus plinii as a junior synonym and a juvenile representative of the latter species. With his review of the fossil reptiles from Perledo, Peyer (1933-1934) proved Curioni's (1863) claim was wrong by demonstrat- ing that pachypleurosaurs do occur in the black shales of Perledo (Neusticosaurus pusillus, rede- scribed by Rieppel, 1995a), and he brought the debate over the validity of Macromirosaurus to an end by recognizing the specimen as Lariosau- rus balsami var. plinii. Peyer's (1933-1934) monograph also included an amended diagnosis for the genus Lariosaurus and its only known spe- cies, L. balsami, and therewith provided the basis for all future work on Lariosaurus. Following Peyer's monographic revision, sev- eral additional lariosaur specimens were de- scribed, all of which were referred to Lariosaurus balsami Curioni (Zapfe & Konig, 1980; Sanz, 1983b; Ticli, 1984; Mazin, 1985) and which col- lectively document the abundance and the wide geographic distribution of this species. Among these specimens, however, the original of Mazin (1985) is noteworthy for a number of unique char- acters (discussed below), and it will here be des- ignated the holotype of a new species to be di- agnosed below (Lariosaurus curionii n. sp.). It was not until 1987 that a second species of Lariosaurus was described from the upper Ladin- ian Kalkschieferzone of Monte San Giorgio, southern Switzerland, Lariosaurus lavizzarii Kuhn-Schnyder, 1987. Based on a nondiagnostic juvenile specimen, the latter species was synon- ymized with Lariosaurus balsami by Tschanz (1989), who in turn described Lariosaurus buzzii from the Grenzbitumenzone (Anisian-Ladinian boundary) of Monte San Giorgio, Switzerland. If indeed a Lariosaurus, this specimen would be the earliest representative of its genus, and it would occur only slightly earlier and in the same geo- graphic setting as the purported sister group of Lariosaurus, the genus Ceresiosaurus (Peyer, 1931; see Sues, 1987, and Storrs, 1991, 1993, for a phylogenetic analysis including these two gen- era). The genus Ceresiosaurus was erected by Peyer (1931) on the basis of three articulated specimens and some isolated postcranial elements collected from the lower Meridekalke (lower La- dinian) of Monte San Giorgio. Dissatisfied with the character analysis present- ed by Tschanz (1989), Kuhn-Schnyder (1990) erected a separate genus, Silvestrosaurus, to in- clude buzzii. In the same year, the description of yet another species of Lariosaurus was published, Lariosaurus valceresii Tintori and Renesto, 1990, from the Kalkschieferzone of Valceresio, northern Italy. The discovery of a juvenile specimen from the same locality (Renesto, 1993) once again ac- tivated the discussion surrounding the validity of Lariosaurus lavizzarii Kuhn-Schnyder and the status of Silvestrosaurus buzzii (Tschanz, 1989). Indeed, the question as to how many species of Lariosaurus and related genera should be recog- nized has remained unanswered. It is the purpose of this paper to review the status of the genera Ceresiosaurus, Lariosaurus, Silvestrosaurus, and their constituent species on the basis of a comprehensive review of all mate- rial available in public repositories (see Appendix II). For the purpose of the ensuing discussion, the three genera Ceresiosaurus, Lariosaurus, and Sil- vestrosaurus are considered members of a mono- phyletic clade, collectively referred to as "lario- saurs." Institutional Abbreviations — bsp, Bayerische Staatssammlung fur Palaontologie, Munchen; mcl, Museo Civico, Lecco; mcsnm, Museo Civico di Storia Naturale, Milano; mnhl, Museum d'Histoire Naturelle, Lausanne; pmz, Palaontolo- gisches Institut und Museum der Universitat, Zu- rich; pvhr, Universite Paris VI, Laboratoire de Pa- leontologie et de Paleoanthropologie, Paris; SB, Museo y Laboratorio de Geologia, Seminario de Barcelona; smf, Forschungsinstitut und Naturmu- seum Senckenberg, Frankfurt a.M.; ugr, Ufficio Geologico di Roma. Materials and Methods The personal inspection of all of the material of Lariosaurus deposited in public repositories forms the basis for this review. However, all of the material discussed in this paper (except the small specimen of Lariosaurus from the Natural History Museum in Lausanne; see Appendix II) has previously been described and figured in de- tail (see particularly Ticli, 1884; Boulenger, 1898; Mariani, 1923; Peyer, 1931, 1933-1934; Sanz, FIELDIANA: GEOLOGY 8* FRANCE 1 GERMANY < y w switzer- C LAND * AUSTRIA^ 5* j~^r\ 4* *2 \ SLOVENIA • Milano ~m ITALY f Vienna SPAIN Marseille Barcelona Fig. 1. Locality map for the sites that have yielded Lariosaurus. 1, Calcare di Perledo, Perledo and Esino; 2, Calcare di Perledo, Lecco; 3, Grenzbitumenzone and lower Meridekalke and Kalkschieferzone, Monte San Giorgio; 4, Kalkschieferzone, Ca del Frate; 5, Partnach-Plattenkalk, Gailtaler Alps (Kellerberg Quarry near Villach); 6, Black shales, Amelie-les-Bains; 7, Muschelkalk, Montral and Alcover; 8, Keuper, Sulzheim (near Wurzburg). 1976, 1983b; Mazin, 1985; Kuhn-Schhnyder, 1987; Tschanz, 1989; Renesto, 1993; Rieppel, 1994a). Unfortunately, all specimens of Ceresio- saurus but the one kept at the Natural History Museum in Basel are currently unavailable for in- vestigation, which limits character analysis for this taxon to one adult specimen and the original description by Peyer (1931). It is for these reasons that the anatomy of lariosaurs is here described in terms of character definitions only. Illustration of lariosaur anatomy is by photographic plates based on specimens available for photography and is de- signed to complement plates and figures already existing in the literature. Illustrations in this paper cannot replace the excellent plates published by Peyer (1933-1934). Peyer's monograph has been reprinted by the Servicio Geologico d' Italia, which is why Curioni's material kept at the Uffi- cio Geologico di Roma was not available for pho- tography. The Stratigraphic and Geographic Distribution of Lariosaurus A variety of localities have yielded Lariosaurus specimens, as enumerated below (see Fig. 1 for geographic locations and Fig. 2 for stratigraphic relations): Calcare di Perledo The holotype of Lariosaurus balsami (lost in World War II; Fig. 3) and all the specimens re- ferred to that taxon by Curioni (1847, 1863) came from the black shales of Perledo above Varenna at Lake Como, northern Italy (southern Alps). Ad- ditional specimens from the same deposits were described by Boulenger (1898; Fig. 4) and Mari- ani (1923; Fig. 5). Among these specimens, the original holotype (a cast of which is kept at the Museo Civico di Storia Naturale in Milano, un- catalogued) was the largest; the next largest spec- imen (kept at the Bayerische Staatssammlung fur Palaontologie und Historische Geologic Munich, bsp AS I 802) was selected as the neotype for Lariosaurus balsami by Kuhn-Schnyder (1987; Peyer, 1933-1934, PI. 32). The precise age of these historical fossil col- lections from Perledo cannot be determined un- equivocally today because precise stratigraphic and locality data are lacking. Tintori et al. (1985) noted that most of the historical fossil material RIEPPEL: REVISION OF LARIOSAURUS Strata yielding Lariosaurus Stratigraphical occurrence of Lariosaurus U i-h CO CO < H w Q Q o cd u -J 1 o I 1 1 e b & a C/5 2.1 o oo a. S3 o o CO =1 ■a a a 3 a 21 3 I 8.1 3 mu3 1 1 I ■■8 1 8 J * 3 3 "g3 1 i ■S3 1 3 "3 | 8 ! 5 a u I I I ? I 1^ Fig. 2. The stratigraphic distribution of Lariosaurus species. appears to have been collected in the surroundings of the village of Perledo, i.e., in the upper part of the Calcare di Perledo, recognized as the Perledo Member of the Perledo- Varenna Formation, of up- per Ladinian age (Gaetani et al., 1992). At this locality and time, Lariosaurus balsami occurs to- gether with the pachypleurosaur Neusticosaurus pusillus Seeley (Rieppel, 1995a). An isolated left foot from Esino, close to Per- ledo, was described by Boulenger (1891, p. 292) under the name Eupodosaurus longobardicus be- fore he realized that the specimen is, in fact, La- FIELDIANA: GEOLOGY Fig. 3. Holotype of Lariosaurus balsami (cast, uncatalogued, kept at the Museo Civico di Storia Naturale, Milano). Fig. 4. Lariosaurus balsami (smf R-13, original of Boulenger, 1898). RIEPPEL: REVISION OF LARIOSAURUS Fig. 5. Lariosaurus balsami (mcsnm uncatalogued, original of Mariani, 1923). riosaurus balsami (Boulenger, 1 898) and had pre- viously been described by Curioni (Curioni, 1863, PI. 7, Fig. 1). Two further specimens of Lariosau- rus balsami were collected in equivalent deposits in the surroundings of Lecco, south of the type locality of the Calcare di Perledo, and described by Ticli (1984; Figs. 6, 7). Kalkschieferzone Grenzbitumenzone The Grenzbitumenzone of Monte San Giorgio (Anisian-Ladinian boundary, southern Switzer- land) has yielded the holotype of Silvestrosaurus buzzii Tschanz, 1989, along with abundant mate- rial of other sauropterygians (the pachypleurosaur Serpianosaurus Rieppel, 1989a, and the nothosaur " Paranothosaurus" [a junior synonym of Notho- saurus: Rieppel & Wild, 1996]). The Kalkschieferzone (Senn, 1924; Furrer, 1995) is the upper member of the Meridekalke (Wirz, 1945), of uppermost Ladinian age. Out- crops in Val Mare, Monte San Giorgio, the south- ern Alps (Switzerland) have yielded the juvenile specimen described by Kuhn-Schnyder (1987) as Lariosaurus lavizzarii. No pachypleurosaurs or other fossil reptiles have yet been collected in Swiss outcrops of the Kalkschieferzone (Furrer, 1995). Equivalent outcrops in Valceresio (at Ca del Frate near Viggiu, Varese, northern Italy) have yielded the holotype of Lariosaurus valceresii Tintori and Renesto, 1990, as well as a juvenile specimen of Lariosaurus (Renesto, 1993; Fig. 8). The Ca del Frate locality has also yielded the ho- lotype of the pachypleurosaur Neusticosaurus (Pachypleurosaurus) edwardsii (Cornalia, 1854), but from an older quarry located in earlier strata of late lower Ladinian age; the taxon otherwise occurs in lower to middle Ladinian deposits of Monte San Giorgio (Sander, 1989). Lower Meridekalke The Meridekalke lie on top of the Grenzbitu- menzone at Monte San Giorgio. Lower Meride- kalke outcrops (Cava inferiore beds, Cava supe- riore beds, and Cassina beds; Furrer, 1995) of lower Ladinian age have yielded Ceresiosaurus calcagnii (Peyer, 1931), along with abundant pa- chypleurosaur material (Neusticosaurus; Sander, 1989). Partnach-Plattenkalk The Partnach-Plattenkalk (Warch, 1979; also known as Partnachschichten or "Plattenkalk" [Zapfe & Konig, 1980]), spans the entire Ladini- an. Outcrops in the Gailtaler Alps (northern Alps, Karnten, Austria) have yielded Lariosaurus cf. L. balsami (Zapfe & Konig, 1980; Warch, 1984; Rieppel, 1994a) along with Neusticosaurus (Psi- FIELDIANA: GEOLOGY Fig. 6. Lariosaurus balsami (mcl 202, original of Ticli, 1984). lotrachelosaurus) toeplitschi Nopcsa, 1928a (see also Rieppel, 1993b) and other indeterminate pachypleurosaur remains. According to Zapfe and Konig (1980), the greater part of the quarry that yielded Lariosaurus specimens is located in the upper unit of the Partnach-Plattenkalk, of late Ladinian age. Warch (1984) emphasized that La- riosaurus was found immediately above an inter- calated bed of marly shales at the middle of the lithological column of the Partnach-Plattenkalk, which indicates a middle Ladinian age. A very incomplete skeleton from the Gailtaler Alps was described as Proneusticosaurus carin- thiacus by Arthaber (1924). The exact locality for this fossil remains doubtful, as it was labeled "Bleiberg?" only. Bleiberg is an important min- ing area with exposures of the Wetterstein-Kalk of late Ladinian and early Carnian age (Zeeh, Fig. 7. Lariosaurus balsami (mcl 663, original of Ticli, 1984). RIEPPEL: REVISION OF LARIOSAURUS 5 cm ':':--,..;.','^B •"; : . :- , -M'*': Fig. 8. Lariosaurus balsami (Museo Civico di Szienze Naturali di Induno Olona P 550, original of Renesto, 1993). 1994), which yielded an ichthyosaur (Shastasau- rus carinthiacus Huene, 1925; see also Mc- Gowan, 1994). Lithological clues seem to indi- cate, however, that the specimen is not from the Wetterstein-Kalk but rather from the Partnach- Plattenkalk, as are the other Lariosaurus speci- mens from the Gailtaler Alps (Warch, 1984). In- deed, the specimen in question has nothing in common with Proneusticosaurus Volz, 1902, re- described by Rieppel and Hagdorn (1997). In- stead, it represents the badly eroded pelvic region of a Lariosaurus (Zapfe & Konig, 1980), of a size comparable to the neotype of Lariosaurus balsa- mi, and hence distinctly larger than the other La- riosaurus from the same deposits (Fig. 9). Black Shales of Amelie-les-Bains An incomplete specimen of Lariosaurus was collected along with microvertebrate remains in the black shales of Amelie-les-Bains, eastern Pyr- enees. The microvertebrate (fish) fauna (Mazin & Martin, 1983), as well as the occurrence of Lari- osaurus, may suggest a Middle Triassic (Ladini- an) age (Mazin, 1985), but no detailed stratigraph- ic studies have addressed the age of these fossil- iferous outcrops as yet. The specimen of Lario- saurus from this locality was referred to L. balsami by Mazin (1985), but is here designated as the holotype of a new species. Fig. 9. Holotype of Proneusticosaurus carinthacus Arthaber, 1924. FIELDIANA: GEOLOGY Spanish Muschelkalk The "Muschelkalk superior" of northeastern Spain (outcrops located between Mont-ral and Al- cover, Province Tarragona) has yielded a rich ver- tebrate fauna, including marine reptiles reviewed by Sanz et al. (1993). The age of these deposits has been determined as middle to upper Ladinian (Esteban Cerda et al., 1977; Hemleben & Freels, 1977; Via Boada et al., 1977). Preservation in these calcareous shales is unique in that dolomi- tization destroyed all original skeletal material, rendering morphological analysis of the material rather difficult. Sauropterygians from that locality have been identified as Lariosaurus balsami, Nothosaurus cymatosauroides, and a problematic pistosaur (Sanz, 1976, 1983a,b; Sanz et al., 1993; Alafont & Sanz, 1996). A recent survey of the fauna indicated the presence of Ceresiosaurus (an incomplete specimen held at the Centre d'Historia Natural de la Conca de Barbera, Montblanc), while some of the specimens referred to Lario- saurus balsami by Sanz (1976, 1983b) may in fact represent an as yet undescribed pachypleurosaur taxon. Lariosaurus generally has an elongated skull with an elongated and constricted rostrum and an upper temporal fossa between one and two times as long as the longitudinal diameter of the orbit. Some small sauropterygians from the Mon- tral-Alcover area show a relatively short preor- bital skull without constriction, large orbits, and a postorbital skull that, as a whole, measures ap- proximately 70% of the longitudinal diameter of the orbit (for example, the specimen DeLucas I, figured by Sanz, 1983b, PI. 3, Fig. B). That these skull proportions should be a juvenile character of Lariosaurus is unlikely in view of the juvenile specimens described by Kuhn-Schnyder (1987) and Renesto (1993). On the other hand, the spec- imens share with Lariosaurus and the Chinese pachypleurosaur Keichousaurus a distinctive hu- merus morphology (discussed below), as well as the broadened ulna. Germanic Keuper The lower Keuper (Lettenkeuper) of the Ger- manic Triassic (upper Ladinian) has yielded a dis- tinctly broadened ulna (Rieppel, 1994b, Fig. 61 A), which on the basis of its morphology can be referred to Ceresiosaurus. The upper Keuper (Gipskeuper, uppermost Ladinian) of Sulzheim near Wurzburg (southern Germany) has yielded the poorly preserved skeleton of a sauropterygian described by Schultze and Wilczewski (1970), who compared the specimen either to Ceresiosau- rus or to Lariosaurus. The Lettenkeuper has also yielded the type material of Neusticosaurus pu- sillus Seeley, 1882. Previous Cladistic Analyses of Lariosaur Interrelationships Sues (1987) first recognized the sister-group re- lationship of Lariosaurus and "Ceresiosaurus," and considered those two clades to represent the sister group of Nothosaurus. These results were corroborated by subsequent studies of Storrs (1991) and Rieppel (1994b). In an analysis pre- sented by Sanz et al. (1993), eusauropterygian (sensu Tschanz, 1989) relationships are shown to be fully unresolved in a strict consensus tree, but in their preferred cladogram (Sanz et al., 1993, Fig. 14), these authors again support a sister- group relationship for Lariosaurus and "Ceresio- saurus," which together form the sister-group of Nothosaurus (and "Paranothosaurus"). I reanalyzed the data matrix published by Sanz et al. (1993, Table I) using the software package PAUP (version 3.1.1) developed by David L. Swofford (Swofford, 1990; Swofford & Begle, 1993). With the branch-and-bound search option implemented, and rooting the ingroup on their outgroup (which represents an all-0-ancestor), I obtained six most parsimonious trees (MPTs) with a tree length (TL) of 46, a consistency index (CI) of 0.826, and a rescaled consistency index (RC) of 0.723. The sister-group relationship of Lario- saurus and "Ceresiosaurus" is supported in all six trees, and in all six trees this clade falls into an unresolved polytomy with Nothosaurus, "Para- nothosaurus," and all other Eusauropterygia (which in turn form a monophyletic clade sensu Tschanz, 1989). Nothosaurus and "Paranotho- saurus" fail to come out as sister groups because of the unknown character states for characters 1 7 and 25. Whereas Rieppel (1993a) considered "Silves- trosaurus" as a subjective junior synonym of La- riosaurus because its diagnosis is based on ple- siomorphy, Storrs (1993) added "Silvestrosau- rus" to his analysis of sauropterygian interrela- tionships and found it to be the sister group of a clade comprising Lariosaurus and "Ceresiosau- rus." To test the validity of "Silvestrosaurus" as RIEPPEL: REVISION OF LARIOSAURUS a separate taxon, I reanalyzed the data matrix pub- lished by Storrs (1993) with all 88 characters in- cluded (of which characters 10, 40, 50, 54, 55, and 72 are uninformative and hence were ig- nored). Heuristic search settings employed ran- dom stepwise addition (10 replications), and branch swapping (on minimal trees only) was ef- fected by tree bisection and reconnection. Rooting the monophyletic ingroup on a paraphyletic out- group including Captorhinomorpha, Petrolaco- saurus, Younginiformes, and Claudiosaurus yielded four equally parsimonious trees (TL = 187, IC = 0.688, RC = 0.527). The strict consen- sus tree shows " Silvestrosaurus" in an unresol- ved trichotomy with the "Ceresiosaurus^-Lar- iosaurus clade, on the one hand, and the Notho- saurus-''Paranothosaurus'1'' clade on the other. Three out of the four MPTs (75%) show "Silves- trosaurus" to pair with the Nothosaurus-" Par- anothosaurus" clade. Synapomorphies shared by "Silvestrosaurus" and the Nothosaurus-" Paran- othosaurus" clade are 19(1), 27(1), 29(1), and 33(1) with ACCTRAN character optimization, and 14(1), 27(1), 29(1), and 33(1) with DEL- TRAN character optimization. Rooting all taxa in- cluded in Storr's (1993) data matrix on an all-0- ancestor using the same search settings again yielded four MPTs (TL = 189, CI = 0.672, RC = 0.546), with identical results with respect to the position of "Silvestrosaurus." Whereas the unresolved position of "Silvestro- saurus" in the strict consensus tree might raise doubts as to its generic identity, its pairing with the Nothosaurus-" Paranothosaurus" clade in the 50% majority rule consensus tree would seem to contradict its status as a junior synonym of La- riosaurus. Closer inspection of the data matrix published by Storrs (1993) indicates a number of characters for which " Silvestrosaurus" is coded differently than Lariosaurus. These are as fol- lows: nasals contact prefrontals in Lariosaurus, but not in " Silvestrosaurus" (14); postfrontal en- ters upper temporal fenestra in Lariosaurus, but not in "Silvestrosaurus" (19 — mistaken coding?); pineal foramen displaced posteriorly in Lariosau- rus, but not in " Silvestrosaurus" (28 — but see the juvenile Lariosaurus described by Renesto [1993]); rostrum not constricted in Lariosaurus, constricted in "Silvestrosaurus" (33); sacral ribs distally expanded in "Silvestrosaurus," distally reduced in Lariosaurus (52); rib pachyostosis present in Lariosaurus, but not in "Silvestrosau- rus" (53); supracoracoid foramen/notch present in Lariosaurus, but not in "Silvestrosaurus" (64); entepicondylar foramen present in Lariosaurus, but not in "Silvestrosaurus" (76); ulna broad in Lariosaurus, but not in "Silvestrosaurus" (83). Many of these characters, as well as those cited by Kuhn-Schnyder (1990) in support of "Silves- trosaurus," require greater scrutiny, as discussed below. Character Analysis General Morphology " Ceresiosaurus" calcagnii is known from sev- eral specimens, all but one of which are currently not accessible for detailed investigation. "Silves- trosaurus" buzzii is known from a single, incom- plete, and disarticulated specimen described in de- tail by Tschanz (1989). Specimens referred to the genus Lariosaurus are frequent throughout Ladin- ian deposits of the Alpine Triassic and, because of a variable degree of pachyostosis, bear a su- perficial resemblance to pachypleurosaurs often found at the same localities. The detailed mor- phology of lariosaurs is distinct from that of pachy- pleurosaurs, however, and rather closely resem- bles that of Nothosaurus. The general morpholog- ical description of the skeletal anatomy of lario- saurs provided in this section will be followed by a more detailed analysis of selected characters im- portant for cladistic analysis of lariosaur interre- lationships. The skull of Lariosaurus is distinctly depressed and elongated, with an elongated postorbital re- gion characterized by large upper temporal fossae distinctly larger than the orbits. The rostrum is elongated and constricted, and the premaxillary and anterior dentary teeth are distinctly enlarged (fanglike) and strongly procumbent. Kuhn-Schny- der (1987, p. 18) found the Lariosaurus specimen from the Montral-Alcover locality kept at the Museum of the Solnhofer Aktien-Verein, Max- berg, to show certain "anomalies," and he may have referred to seemingly aberrant skull propor- tions, as they appear in Sanz (1983b, PI. 5, Fig. 1). However, this is a false impression created by the difficulties in photographing the specimens from the Montral-Alcover locality. Investigation of the original specimen showed the skull to share the elongated, distinctly constricted rostrum. Lari- osaurus shares with Nothosaurus the presence of paired maxillary fangs located at a level between the external naris and the orbit. And as in Notho- 10 FIELDIANA: GEOLOGY saurus, the parietal and squamosal are elaborated into an occipital crest rising above the occiput. The occiput is closed and platelike, with the su- praoccipital more or less horizontally oriented. Unfortunately, the detailed morphology of the oc- ciput remains incompletely known for Lariosau- rus, in particular the taxonomically important re- lations of the basioccipital to the dermal palate (Rieppel, 1994c), although these are assumed to be similar to Nothosaurus. The lower jaw of La- riosaurus is a slender and delicate structure with- out a distinct coronoid process. The surangular bears a laterally protruding flange for the insertion of superficial jaw adductor muscle fibers (Tschanz, 1989). The retroarticular process is dis- tinct. The vertebrae of Lariosaurus show swollen or dome-shaped (pachyostotic) pre- and postzyg- apophyses and a very low neural spine, much like pachypleurosaurs. Lariosaurus balsami shows 43 to 45 presacrals (42 in the holotype of L. valce- resii; 47 in the Basel specimen of "Ceresiosau- rus"), of which 19-23 are cervicals (located in front of the clavicular-interclavicular complex; 22 cervicals in the holotype of L. valceresii; 23 in the Basel specimen of "Ceresiosaurus"). Cervi- cal ribs are present throughout the cervical ver- tebral column with the probable exception of the atlas (Peyer, 1933-1934, PI. 35). They are, how- ever, often incompletely exposed and visible in the posterior cervical region only. The cervical ribs bear a distinct anterior process. The dorsal ribs show a variable degree of pachyostosis, as discussed in detail below. The sacrum is defined by a cluster of tightly juxtaposed ribs converging with a tapering distal end toward the dorsal pro- cess of the ilium. The number of sacral ribs varies from four to five pairs. The tail is completely pre- served in the Frankfurt specimen (smf R-13), but the exact vertebral count is difficult to establish. Dislocation of the pelvic elements obscures the proximal caudal region, and individual vertebrae are difficult to distinguish at the tapering tip of the tail, but 32 caudal vertebrae can unequivocally be identified, the total probably being 37 or 38. The Maxberg specimen shows a total of 36 caudal vertebrae with few, if any, missing. The proximal caudal ribs differ from the posterior sacral ribs by their greater length and by their orientation in a posterolateral rather than anterolateral direction. Posteriorly, the caudal ribs rapidly decrease in size, the last ones assuming a knoblike shape; they do not seem to be present beyond the 15th or 16th caudal. The closely juxtaposed gastral ribs form a sturdy ventral armor. There are two gastral ribs per vertebral segment. Each gastral rib is composed of five elements: a median, slightly an- gulated rib flanked by two slightly curved and overlapping elements on either side. The clavicular-interclavicular complex of the pectoral girdle shows pronounced anterolateral corners, emphasized by pachyostosis of the cla- vicula. The interclavicle bears no trace of a pos- terior stem or process. As in other eosauropteryg- ians, the clavicle is applied against the antero- medial surface of the dorsal wing of the scapula. The humerus of Lariosaurus is morphologically distinct. It is distinctly curved and characterized by a weak development of the deltopectoral crest (in Lariosaurus balsami), as well as by the ab- sence of a distinct crest for the insertion of the latissimus dorsi muscle on its postaxial surface. The width of the humerus increases gradually to- ward the distal end. A distinct sexual dimorphism is expressed in the proportions of the humerus in pachypleurosaurs (Rieppel, 1989a, 1993b; Sander, 1989), but no such dimorphic proportions of the humerus can be detected in the sample of lario- saurs deposited in public repositories. The dis- tinctly broadened ulna is very characteristic in Lariosaurus. The radius is slightly shorter than the ulna and much more slender. Between radius and ulna remains a distinct spatium interosseum, distal to which lies the intermedium. The number of carpal ossifications varies in a pattern discussed in detail below. The manus shows a tendency to- ward hyperphalangy, which reflects the general observation that the forelimb is more strongly de- veloped than the hind limb in Lariosaurus. The pelvic girdle is notable for the further re- duction of the dorsal wing of the ilium, reduced to a stocky dorsal process. The obturator foramen in the distinctly waisted pubis is slitlike and re- mains open in the adult. The fenestra thyroidea separates the pubis from the ischium. The ischium has a relatively narrow, rounded dorsal head but shows a distinct ventral expansion. Its ventral margin is strongly convex. The femur is a slender, slightly sigmoidally curved bone that in general is much more lightly built than the humerus but remains slightly longer than the humerus in Lariosaurus, including the large neotype of L. balsami (bsp AS I 802); the humerus is longer than the femur in the large (adult) "Ceresiosaurus" specimens due to its al- lometric growth. Tibia and fibula show no partic- ular differentiation, and they enclose a spatium interosseum distal to which lies the astragalus. RIEPPEL: REVISION OF LARIOSAURUS 11 B^tafcv^a - ■ h^H [El |SSM| 1 1 2 cm 1 1 1 ' 1 Fig. 10. The skull of Lariosaurus in dorsal view. A, Lariosaurus balsami (neotype, bsp ASI 802); B, L. balsami (smf R-13, original of Boulenger, 1898); C, L. valceresii (holotype, Museo Civico di Szienze Naturali di Induno Olona P 500); D, L. curionii n. sp. (holotype, pvhr 1); E, L. balsami (mcsnm uncatalogued, original of Mariani, 1923); F, Lariosaurus sp. Museo (Civico di Szienze Naturali di Induno Olona P 550, original of Renesto, 1993). Tarsal ossifications vary in a pattern discussed in detail below. Hyperphalangy in the pes is restrict- ed to specimens referred to " Ceresiosaurus." The Skull The morphological analysis of lariosaurs is ren- dered difficult by the often poor preservation and/ or preparation of the sometimes incomplete and always dorsoventrally compressed material (Fig. 10). Information on sutural characteristics of the skull will therefore remain limited. Premaxilla-frontal Contact — In "Silvestro- saurus," fused nasals form a relatively broad dor- sal bridge between the external nares (the nasals appear paired in Kuhn-Schnyder, 1974, Fig. 12). The posterior (nasal) process of the premaxilla ap- pears unusually short due to breakage of its pos- terior tip, and as preserved, the premaxilla re- mains widely separated from the frontal. This is in contrast to other lariosaurs, where the dorsal 12 FIELDIANA: GEOLOGY bony bridge between the external nares is rela- tively narrower, the posterior (nasal) processes of the premaxillae are more elongate, and the nasals are paired. Dividing the dorsal bridge between the orbits (width of the frontal) by the dorsal bridge between the external nares yields a ratio of 1 . 1 for "Silvestrosaurus" and values ranging from 1.2 to 2.1 in Lariosaurus; the only exception is the La- riosaurus described by Kuhn-Schnyder (1987, pmz T4288), with a corresponding ratio of 1.0, which reflects the relatively large orbits in this juvenile specimen. In pvhr 1 and pmz T4288, the posterior (nasal) processes of the premaxillae con- tact the anteromedial process of the frontal, whereas the nasals seem to contact each other be- hind the premaxillary processes in the holotype of L. valceresii. A similar variation in the relations of the premaxillae, nasals, and frontal is observed in Neusticosaurus (Sander, 1989) and Nothosau- rus (Rieppel & Wild, 1996), where the nasals may cover the contact between premaxilla and frontal to a variable degree. The relatively broad and fused nasal is an autapomorphy of "Silvestrosau- rus." Prefrontal-Nasal Contact — In "Silvestro- saurus," an anterolateral process of the frontal contacts the ascending (medial) process of the maxilla, thus separating the nasal from the pre- frontal. The only other specimen that shows su- tural details in the preorbital skull is pmz T4288, where the nasals are seen to contact the prefrontal. In this specimen, the frontal is figured without an- terolateral processes, which, if correct, is a con- dition highly unusual in Sauropterygia. The only other sauropterygian with no anterolateral pro- cesses of the frontal is the Chinese pachypleuro- saur Keichousaurus. As figured, the anterior end of the frontal is asymmetrical in pmz T4288, which appears to be the result of breakage. The best preserved Lariosaurus skull, pvhr 1 (Fig. 11), shows a distinct yet short anterolateral pro- cess of the frontal on the left side, leaving enough room for the nasal to contact the prefrontal. Un- fortunately, the presence of such a contact cannot be ascertained, owing to damage of the bone sur- face in the critical area on both sides of the skull. Skulls of Simosaurus (Rieppel, 1994b) and Noth- osaurus (Rieppel & Wild, 1996) show bilateral asymmetry of the presence versus absence of a contact of nasal and prefrontal. Postfrontal Relations — In "Silvestrosaurus" and Lariosaurus, the pre- and postfrontal remain separated at the dorsal margin of the orbit. "S/7- vestrosaurus" shows a broad postfrontal, which sq Fig. 11. The skull of Lariosaurus curionii n. sp. in dorsal view (holotype. pvhr 1). Abbreviations: bo, ba- sioccipital; eo, exoccipital; f, frontal; m, maxilla; n, na- sal; p, parietal; pm, premaxilla; po, postorbital, pof, post- frontal; prf, prefrontal; so. supraoccipital; sq, squamosal. Scale bar = 10 mm. defines the anteromedial margin of the upper tem- poral fossa. A similar postfrontal is reconstructed for L valceresii by Tintori and Renesto (1990), and the entry of the postfrontal into the antero- medial margin of the upper temporal fossa is dis- tinct in smf R-13 (right side). Interestingly, this contrasts with pvhr 1 (Fig. 1 1 ), where the post- frontal appears as a much smaller element located at the posteromedial margin of the orbit, excluded from the upper temporal fossa by the postorbital. The latter element reaches high up in the postor- bital arch to meet a lateral extension of the pari- etal, a condition otherwise not known in saurop- terygians. RIEPPEL: REVISION OF LARIOSAURUS 13 Jugal Relations — "Silvestrosaurus" was originally figured with a jugal extending anteri- orly along the ventral margin of the orbit (Tschanz, 1989), restricting the maxilla to an an- terior position (same in Kuhn-Schnyder, 1974, Fig. 12). This is a highly unusual configuration of the jugal and maxilla for a nothosaurian eosau- ropterygian. In fact, the jugal cannot be identified unequivocally in "Silvestrosaurus" (Tschanz, 1989, p. 159) or Lariosaurus (Peyer, 1933-1934, p. 24, identified a jugal in the Munich specimen bsp AS I 802, currently mounted for permanent exhibit and hence difficult to analyze). Indeed, the jugal seems to be absent in the relatively well- preserved and acid-prepared specimen pvhr 1 (Fig. 11). For lack of adequate preservation of other specimens, it remains unknown whether the absence of a jugal is unique to specimen pvhr 1 or shared by other Lariosaurus. A jugal bone is present in "Ceresiosaurus" indicating that loss of the jugal could be a derived character of La- riosaurus that is shared by "Silvestrosaurus." Corroboration of this hypothesis requires better preserved specimens, however. Parietal Morphology — " Silvestrosaurus" shows an unusually broad parietal skull table with the pineal foramen shifted to a position only slightly behind the midpoint of the parietal. Dor- soventral compression may add to the impression of a wide parietal skull table, which nevertheless shows some constriction behind the pineal fora- men. This constriction is much more pronounced in Lariosaurus, where the parietal has a distinct morphology, at least in the smaller specimens. It is relatively broad anteriorly, with straight and parallel lateral edges between the anterior two- thirds of the upper temporal fenestrae. The degree of posterior displacement of the pineal foramen is somewhat variable. The foramen may lie in a rather forward position as in smf R-13, which in this respect is comparable to " Silvestrosaurus," or its posterior displacement may be more pro- nounced, but it never reaches the immediate prox- imity of the posterior margin of the parietal skull table as in "Ceresiosaurus" and in some Notho- saurus specimens. Behind the pineal foramen, the parietal skull table shows a marked constriction that is distinctly set off from the anterior part of the skull table in smaller Lariosaurus; in larger specimens (bsp AS I 802, and holotype of L. val- ceresii), this posterior parietal constriction ap- pears less abrupt. It is interesting to note that the juvenile specimen of Lariosaurus described by Renesto (1993) resembles "Silvestrosaurus" rath- er closely by showing a broad parietal skull table and a relatively anterior position of the pineal fo- ramen. Parietal morphology in "Silvestrosaurus" is reversed (on the basis of DELTRAN character optimization; see discussion of cladistic analysis below), seemingly as a result of paedomorphosis. Rostrum Constriction — The elongated ros- trum is distinctly constricted in "Ceresiosaurus," "Silvestrosaurus," and Lariosaurus, as is also the case in Nothosaurus. In juvenile Lariosaurus specimens, rostral constriction may be weakly pronounced (Renesto, 1993), and a rostral con- striction is absent in the skull from the Pyrenees (Fig. 11; pvhr 1, original of Mazin, 1985). Divid- ing the width of the skull at the level in front of the orbits by the width of the skull at the rostral constriction yields a ratio of 1.8 in "Silvestrosau- rus," 1.2-2.0 in Lariosaurus. Dividing the maxi- mal width of the premaxillary rostrum by the width of the skull at the rostral constriction yields a ratio of 1.0 in "Silvestrosaurus," 0.9-1.4 in Lariosaurus. Dividing the distance from the tip of the snout to the anterior margin of the external naris by the width of the skull at the rostral con- striction yields a ratio of 0.9 in "Silvestrosaurus," 0.6-1.2 in Lariosaurus. Relative Rostrum Length — The relative length of the rostrum is similar in "Silvestrosau- rus" and Lariosaurus. Dividing the distance from the tip of the snout to the anterior margin of the orbit by the distance from the tip of the snout to the anterior margin of the external naris yields 2.0 for "Silvestrosaurus," 1.8-2.1 for Lariosaurus. Dividing the distance from the tip of the snout to the anterior margin of the upper temporal fossa by the distance from the tip of the snout to the anterior margin of the external naris yields 3.7 for "Silvestrosaurus," 2.8-3.9 for Lariosaurus. Relative Size of the Upper Temporal Fos- sa— The relatively small upper temporal fossa of "Silvestrosaurus" has played a major role in dis- cussions of the validity of that genus (Tschanz, 1989; Kuhn-Schnyder, 1990). The difficulty here is that the size of the temporal fossa has been compared to skull length or to the size of the or- bit, respectively, which may be problematic in view of the negative allometric growth of the orbit and the possibility of allometric growth of the ros- trum. On the other hand, the size of the temporal fossae cannot be compared to a standard mea- surement of the postcranial skeleton (such as the length of the last four presacral centra), since the postcranial skeleton of "Silvestrosaurus" is com- pletely disarticulated. 14 FIELDIANA: GEOLOGY Keeping these provisions in mind, the division of the longitudinal diameter of the orbit by the distance from the tip of the snout to the back end of the supraoccipital (the posterior cranial land- mark most easily identified in the specimens from Montral-Alcover) yields 0.2 for "Silvestrosau- rus" and all Lariosaurus included in the analysis. Division of the longitudinal diameter of the upper temporal fossa by the distance from the tip of the snout to the back end of the supraoccipital yields 0.3 for "Silvestrosaurus" and 0.2-0.3 for Lario- saurus. Division of the longitudinal diameter of the upper temporal fossa by the distance from the tip of the snout to anterior margin of the upper temporal fossa yields 0.4 for "Silvestrosaurus'"' 0.3-0.6 for Lariosaurus. Division of the longitu- dinal diameter of the upper temporal fossa by the longitudinal diameter of the orbit yields 1.0 for "Silvestrosaurus," 1.0 (1 . 1) — 1 .8 for Lariosaurus. A closer look at these values indicates that the upper temporal fossa is equal in size to the orbit in " Silvestrosaurus," whereas the longitudinal di- ameter of the upper temporal fossa is between 1 .4 (in the juvenile described by Renesto, 1993) and 1.8 (in bsp AS I 802 and in the specimen de- scribed by Mariani, 1923) times the longitudinal diameter of the orbit in Lariosaurus. The one ex- ception is a specimen from Montral-Alcover (sb M-501), with a lower jaw length of 50.5 mm (tip of snout to back end of supraoccipital 43.5 mm). The longitudinal diameter of the upper temporal fossa is distinct on the left side of the skull (8.7 mm), the longitudinal diameter of the orbit is 8.1 mm (left) and 8.5 mm (right) respectively, yield- ing a quotient of 1.02 to 1.07. The specimen is a little more than half the size of "Silvestrosaurus," but shows much smaller temporal fossae relative to orbital size than juvenile Lariosaurus (Renesto, 1993). A relatively small upper temporal fossa is plesiomorphic at the level of the Eosauropterygia, and with respect to this character, "Silvestrosau- rus" lies at one extreme of the range of variation observed in Lariosaurus. Postcranial Skeleton Vertebral Count — The presacral vertebral count cannot be established for "Silvestrosau- rus." In Lariosaurus, the presacral vertebral count ranges from 42 (holotype of L. valceresii) to 44. Cervical vertebrae are defined as those lying in front of the pectoral girdle (interclavicle and clav- icle), and their number ranges from 19 to 23. The number of dorsal vertebrae ranges from 20 to 24. These numbers are randomly distributed through- out the sample and do not segregate lariosaurs ac- cording to geographic locality. Sacrum — The number of sacral vertebrae rang- es from four to five in Lariosaurus (Fig. 1 2). This does not imply that four or five sacral ribs actually contact the ilium, but rather that four to five close- ly juxtaposed sacral ribs converge on the dorsal process of the ilium. Storrs (1993) coded the pres- ence of distal l> expanded sacral ribs for "Silves- trosaurus," but in fact the elements identified as (disarticulated) sacral ribs by Tschanz (1989) show a broadened proximal head and a tapering, blunt distal tip, as is also seen in Lariosaurus (as well as in Nothosaurus and "Ceresiosaurus"). Ribs — The dorsal ribs of "Silvestrosaurus" show no pachyostosis, in contrast to most speci- mens of Lariosaurus. Rib pachyostosis is variably expressed in the latter genus, however, and ap- pears to be reduced with increasing size. Rib pachyostosis is distinct in juvenile (Kuhn-Schny- der, 1987; Renesto, 1993) as well as most inter- mediate-sized specimens (not in the relatively small smf R-13), but it is weak or absent in the large neotype of L. balsami and in the relatively large holotype of L. valceresii. (It was weakly ex- pressed in the original holotype of L. balsami.) Pectoral Girdle (Fig. 13) — The clavicle of " 8^65^050^^" differs from that of Lariosau- rus by a generally more slender appearance and by the apparent absence of an expanded antero- lateral edge (Tschanz, 1989, Fig. 6). In fact, the radiograph of the specimen shows a weak antero- lateral expansion of the clavicle (Kuhn-Schnyder, 1974, Fig. 10), which is also present in Lariosau- rus to a variable degree (compare bsp AS I 802, Fig. 13C, with a very distinct anterolateral exten- sion of the clavicle, to the specimen Curioni VI or to the holotype of Macromirosaurus, with a weak expression of that character). The relatively slender shape of the clavicle in "Silvestrosaurus" results from the absence of pachyostosis, which inflates the clavicle in most small and intermedi- ate-sized specimens of Lariosaurus (see diagnosis of the genus given by Peyer, 1933-1934). An an- terolateral expansion of the clavicles is absent (Peyer, 1933-1934) or weakly expressed in "Ce- resiosaurus" (Fig. 13D). The clavicle of "Silvestrosaurus" is narrow and pointed anteromedially and hence does not seem to have met its counterpart in an antero- medial suture. The same is observed in "Ceresio- saurus" (Peyer, 1933-1934). In Lariosaurus, the RIEPPEL: REVISION OF LARIOSAURUS 15 Fig. 12. The sacrum and hind limb of Lariosaurus in dorsal view. A, Lariosaurus balsami (mcsnm uncatalogued, original of Mariani, 1923); B, L. valceresii (holotype, Museo Civico di Szienze Naturali di Induno Olona P 500); C, L. balsami (mcl 202, original of Ticli, 1984); D, L. balsami, left hind limb (mcsnm uncatalogued, original of Mariani, 1923). clavicles meet in an anteromedial suture in front of the interclavicle (pvhr 1, Figs. 13 A, B), as is also the case in Nothosaurus (Rieppel, 1994b). The interclavicle of "Silvestrosaurus" is un- known; that of Lariosaurus (pvhr 1 ; also well ex- posed in the small specimen from the Natural His- tory Museum in Lausanne) and " Ceresiosaurus" (Peyer, 1931) is rhomboidal and shows no rudi- ment of a posterior stem (Fig. 13B). Storrs (1993) coded the supracoracoid notch absent for " Silvestrosaurus." In the Sauropteryg- ia, the coracoid nerve always passes in between the scapula and coracoid (Rieppel, 1994b, as op- posed to piercing the coracoid), and it must have done so in "Silvestrosaurus," since a supracora- coid foramen is absent in the coracoid. The ap- parent absence of the supracoracoid notch (Tschanz, 1989, Fig. 6) may be due to incomplete preparation, to incomplete ossification of the en- dochondral pectoral girdle, and/or to compression of the scapula or coracoid, respectively. Pelvic Girdle — The ilium of " Silvestrosau- rus," Lariosaurus, and "Ceresiosaurus" differs from that of Nothosaurus by further reduction of its dorsal wing. No praeacetabular process is formed by the ilium or by a posteriorly projecting wing (Fig. 12). The pubis of "Silvestrosaurus" lacks the ventral concavity characteristic for the pubis of Simosaurus or Nothosaurus (Rieppel, 1994b). As far as can be inferred from the avail- able material, the pubis shows a convex ventral edge in Lariosaurus. In " Ceresiosaurus," the pu- bis shows a weakly concave ventral edge. Limb Proportions — Kuhn-Schnyder (1990) emphasizes the relatively short humerus (com- pared to the femur) in "Silvestrosaurus" as a character separating this taxon from Lariosaurus. In Lariosaurus, as in all other Sauropterygia, the humerus grows with positive allometry. Dividing the length of the humerus by standard length (de- fined as the length of the last four presacral ver- tebrae) yields 1.0 in juvenile specimens (Kuhn- Schnyder, 1987; Renesto, 1993), and a ratio of 1.4-1.6 for larger specimens. The corresponding value remains unknown for l ulnare > distal carpal (dc) 4 > dc3 > dc2 > dc5 in the carpus, astragalus > calcaneum > distal tarsal (dt) 4 > dt 3 in the tarsus. There are notable exceptions to the correlation of carpal/ tarsal ossifications and absolute body size. The neotype of Lariosaurus balsami (bsp AS I 802; glenoid-acetabulum length 246 mm, Figs. 18A,C) shows only three ossified carpals (intermedium, ulnare, and distal carpal 4) and tarsals (astragalus, calcaneum, and distal tarsal 4), and a relatively large isolated foot (specimen Lucas II, original of Sanz, 1983a, PI. 3C), again shows only three tar- sal ossifications. By contrast, the much smaller Table 1. Proportions of the ulna in Lariosaurus. See text for further discussion. ul-lg mw ul-lg pw ul-lg dw Nothosaurus "raabi" 4.2 2.2 3.4 "Ceresiosaurus" 3.1 2.3 2.8 "Silvestrosaurus" 3.4 2.6 2.2 Lariosaurus 2.2-3.5 1.7 - 2.1 1.8 - 2.3 specimen smf R-13 (Boulenger, 1898, glenoid-ac- etabulum length 70 mm, Figs. 18B,D) has six car- pals (including distal carpals 2 through 5) and four tarsals (including distal tarsal 3, well exposed in left tarsus), and the even smaller specimen kept at the Natural History Museum in Lausanne (un- catalogued, glenoid-acetabulum length 54 mm) shows four ossified carpals. The question may be raised as to whether these specimens represent two separate species (or different sexes of the same species) distinguished by different adult size, the smaller one retaining more carpal (five to six) and tarsal (four) ossifications in the adult than the larger species. However, the original ma- terial of Curioni (1863) includes specimen Cu- Fig. 17. Left zeugopodium and carpus of Lariosaurus calcagnii (mbs, uncatalogued). 20 FIELDIANA: GEOLOGY Fig. 18. The manus and pes of Lariosaurus balsami. A, Zeugopodium and left manus in dorsal view (neotype, bsp ASI 802); B, zeugopodium and left manus in ventral view (smf R-13, original of Boulenger, 1898); C, zeugopodium and left pes in dorsal view (neotype, bsp ASI 802); D, zeugopodium and right pes in ventral view (smf R-13, original of Boulenger, 1898). rioni V.I., represented by the anterior trunk, neck, and skull of similar size as the neotype of La- riosaurus balsami (bsp AS I 802), which has a total of five carpal ossifications; the specimen Cu- rioni VII. I. is an isolated foot, again similar in size to the Munich specimen (bsp AS I 802) with a total of four tarsal ossifications. Specimen 'Cu- rioni VI' (glenoid-acetabulum length 194 mm) is the second largest known specimen of Lariosau- rus balsami, with a total of five carpal and three tarsal ossifications. In fact, a comparison of all adequately preserved Lariosaurus specimens kept in public repositories (Table 2) indicates a poor correlation of the degree of ossification in the car- pus and tarsus with glenoid-acetabulum (trunk) length. The number of carpal or tarsal ossifica- tions by itself does not allow the distinction of two separate taxa of different adult body size within the entire sample, and other than the total number of carpal or tarsal ossifications in the adult (three versus five or six carpals; four versus three tarsals), there is no character supporting the hypothesis that more than one taxon might be rep- resented by the specimens referred to L. balsami. RIEPPEL: REVISION OF LARIOSAURUS 21 Table 2. Number of carpal and tarsal ossifications in relation to body size in Lariosaurus. See text for fur- ther discussion. specimen number specimen description trunk length carpals tarsals PMZ uncatalogued "Ceresiosaurus" 545 6 3 PMZ uncatalogued "Ceresiosaurus" 520 6 3 PMZ T2460 "Ceresiosaurus" 260 4 3(4) BSP AS I 802 Neotype L. balsami 246 3 3 Induno-Olona P500 Holotype L. valceresii 215.5 5(6) 3 PMZ T2462 "Ceresiosaurus" 125 3(4) 3 UGR 4428P "Curioni VI" 193.8 5 4 Maxberg uncatalogued Sanz, 1983 PI. 5, Fig. A 116 ? 3 MCSNM uncatalogued Mariani, 1923 114.5 3 3 MCL 202 Ticli, 1984 109 5(6) 4 SB M-501 Sanz, 1983 PI. 2, Fig. B 74.3 2 2 SMF R-15 Boulenger, 1898 70 6 4 SB M-506 Sanz, 1983 PI. 2, Fig. A 62 2 2 PMZ T4288 holotype "L. lavizzarii" 58 2(1) 1(0) Induno-Olona P550 Renesto. 1993 57.5 1 2 MHNL uncatalogued 54 4 ? UGR 4427P holotype "Macromirosaurus" 52.2 4 2 Peyer (1933-1934, p. 115) arrived at the same conclusion. Phalangeal Formula — Due to incomplete preservation, the accurate phalangeal formula can be established in very few specimens only. An exact count of phalanges is possible in the right manus of the specimen "Curioni V.I.", where the formula is 4-5-5-4 (5?)-3; a similar formula is likely for smf R-13. Specimen SB M-501 from Montral-Alcover shows at least four phalanges in the fifth digit of the left manus. Hyperphalangy in the manus of Lariosaurus is therefore well estab- lished. The pes of Lariosaurus retains the primi- tive phalangeal formula 2-3-4-5-4 (specimens 'Curioni VI' and smf R-13), with the exception of the holotype of L. valceresii. In the latter spec- imen, all four autopodia are incomplete, but the second digit of the left foot shows four phalanges with the ungual in situ, indicating the possibility of mild hyperphalangy in the pes. "Ceresiosau- rus"' is characterized by hyperphalangy both in manus and pes (Tschanz, 1989). Discussion Lariosaurs, a monophyletic clade including "Ceresiosaurus," Lariosaurus, and "Silvestro- saurus," differ from their sister group, the genus Nothosaurus, by a relatively smaller temporal opening with a longitudinal diameter that equals between one and two times the longitudinal di- ameter of the orbit. In Nothosaurus, the longitu- dinal diameter of the upper temporal fossa is al- ways longer than twice that of the orbit. Other relatively plesiomorphic features of lariosaurs that are shared with basal species within the genus Nothosaurus (N marchicus [Rieppel & Wild, 1996]) are a relatively short and broad but dis- tinctly constricted rostrum and a relatively for- ward position of the pineal foramen (which is still located behind the midpoint of the parietal, how- ever). The maxillary tooth row does not extend backward beyond the first third of the temporal fossa. The anterior part of the parietal skull table remains relatively broad, but behind the pineal fo- ramen, the parietal skull table may be strongly constricted without ever being developed into a sagittal crest. Carpal and tarsal ossifications may exceed three in the adult. Lariosaurs differ from Nothosaurus in a num- ber of derived features, most notably the mor- phology of the humerus with no constriction in its middiaphyseal part (in some but not all specimens or species), the broadened ulna, the absence of all traces of a posterior stem on the interclavicle, the presence of four or five sacral ribs (three in Noth- osaurus), the reduced dorsal wing of the ilium (with no praeacetabular process and without pos- terior process), and the potential for hyperpha- langy in manus and pes. Within the lariosaur clade, "Silvestrosaurus" is characterized by relatively small upper temporal fenestrae (equal in size to the orbit), a broad pa- rietal skull table that shows only a weak constric- tion in its posterior part, the pineal foramen lo- cated close behind the midpoint of the parietal, the anterolateral corner of the clavicle only weak- ly expanded, and the absence of pachyostosis. The anteromedial tip of the clavicle is narrow and pointed, suggesting the absence of an anterome- dial suture between the two clavicles as in "Ce- resiosaurus" (Peyer, 1931, PI. 1) but unlike La- riosaurus. "Silvestrosaurus" also differs from Lariosaurus by a relatively short humerus, ab- sence of the entepicondylar foramen, and a rela- tively narrow ulna (yet broader than in Nothosau- rus). The close resemblance of "Silvestrosaurus" 22 FIELDIANA: GEOLOGY to the juvenile specimen of Lariosaurus described by Renesto (1993) suggests that the broad skull table in "Silvestrosaurus" is either a paedo- morphic feature or, alternatively, that the holotype of "Silvestrosaurus" is a juvenile. Paedomor- phosis or a juvenile specimen may also explain the relatively short humerus and, correlated there- with, the absence of the entepicondylar foramen, also absent in juvenile Lariosaurus. Manus and pes of "Silvestrosaurus" are not known. Within lariosaurs, the genus Lariosaurus is characterized by pachyostosis affecting not only the ribs but also the clavicle (with the exception of the holotype of L. valceresii, weakly expressed in large specimens of L. balsami), by a strongly expanded proximal head of the ulna, and by hy- perphalangy in the manus (not known in "Silves- trosaurus"). Lariosaurus valceresii differs from L. balsami by a relatively longer forelimb and by a distinctly waisted humerus with an open and notched ectepicondylar groove. The specimen pvhr 1, which is from the eastern Pyrenees (Ma- zin, 1985), is unique among Lariosaurus by the absence of a rostral constriction and by the exclu- sion of the postfrontal from the anteromedial mar- gin of the upper temporal fossa. To evaluate the status of "Ceresiosaurus" among lariosaurs is difficult at this time because critical material remains inaccessible for analysis. The genus is derived as compared to Lariosaurus by the relatively large forelimbs in the adult, by the presence of hyperphalangy in the pes, and by an increased height of the neural spines in the proximal caudal region (Kuhn-Schnyder, 1974, Fig. 40). To assess the systematic status of the taxa in- cluded in the lariosaur clade, a phylogenetic anal- ysis using parsimony is required to critically ad- dress the significance of the characters distilled from the morphological comparison detailed above. A Case for Monophyly To investigate the interrelationships of lario- saurs, I conducted a phylogenetic analysis using parsimony using the software package PAUP (version 3.1.1), developed by David L. Swofford (Swofford, 1990; Swofford & Begle, 1993). The analysis builds on the data matrix developed by Rieppel (1994b, 1997), with new characters added and old ones redefined as detailed in Appendix I. Ancestor Captorhinidae Araeoscelidia Claudiosaurus Younginiformes Archosauriformes Rhynchosauria Trilophosaurus Prolacertiformes Choristodera Kuehneosauridae Rhynchocephalia Squamata Testudines Placodus Corosaurus Cymatosaurus Pistosaurus Dactylosaurus Serpiano-Neustico Simosaurus Germanosaurus Nothosaurus L. balsami L curionii Ceresiosaurus L. valceresii Silvestrosaurus Fig. 19. Strict consensus tree of 10 equally parsimo- nious trees (TL = 479, CI = 0.630, and RI = 0.762), indicating lariosaur interrelationships. The data matrix (Table 3) includes a total of 27 taxa plus the all-0-ancestor, and a total of 122 characters. Character codings for lariosaurs follow the morphological description given above. In a first run, the Sauropterygia were treated as a monophyletic ingroup rooted on a paraphyletic outgroup that included the Captorhinidae, Testu- dines, Araeoscelidia, Younginiformes, and Clau- diosaurus. Deletion of all other taxa rendered a number of characters uninformative (2, 5, 24, 28, 34, 40, 53, 63, 66, 111, and 117), which were consequently ignored in the analysis. Character 27 was the only multistate character treated as an or- dered transformation series because it implies a logical interdependence of the character states: a lower temporal fenestra must have formed before the lower temporal arch could be lost (Rieppel, 1994b; the alternative of ventral emargination of the cheek in sauropterygians is discussed in this paper). A heuristic search, employing random stepwise addition (10 replications) and branch swapping (on minimal trees only) by tree bisec- tion and reconnection, yielded a total of 10 most parsimonious trees (MPTs) with a tree length (TL) of 310 steps, a consistency index (CI) of 0.645, and a retention index (RI) of 0.746. All 10 trees support the monophyly of lariosaurs (including RIEPPEL: REVISION OF LARIOSAURUS 23 Table 3. Data matrix for the analysis of lariosaur interrelationships. Character definitions are given in Appendix I. 1 1 2 3 4 5 6 7 8 9 1 0 1 Ancestor 0 0 0 0 0 0 0 0 0 0 2 Captorhinidae 0 0 0 0 0 0 0 0 0 0 3 Testudines 0 0 0 0 0 0 0 0 1 0&1 4 Araeoscelidia 0 0 0 0 0 0 0 0 0 0 S Younginiformes 0 0 0 0 0 0 0 0 1 0 6 Kuehneosauridae 0 0 0 0 0 0 0 0 1 0 7 Rhynchocephalia 0 0 0 0 0 0 0 0 1&2 0 8 Squamata 0 0 0 0 0 0 0 0 1&2 0&1 9 Rhynchosauria 1 0 0 0 0 0 0 1 0 1 0 Prolacertiformes 1 0 0 1 0 0 0 1 0 1 1 Trilophosaurus ? 0 0 0 0 0 0 ? 1 1 2 Choristodera 1 0 0 1 0 0 0 1 0 1 3 Archosauriformes 1 0 0 1 0 0 0 1 0 1 4 Claudiosaurus 0 0 0 0 0 0 0 0 1 0 1 5 Dactylosaurus 0 0 0 0 0 0 0 2 0 1 6 Serpiano-Neustico 0 0 0 0 0 0 0&1 2 0 1 7 Simosaurus 0 0 0 0 1 0 1 2 0 1 8 Nothosaurus 0 0 0 0 0&1 2 0 1 9 Ceresiosaurus 0 0 0 0 0 2 0 20 L. balsami 0 0 0 0 1 2 0 21 L. curionii 0 0 0 0 0 1 2 0 22 L. valceresii 0 0 0 0 0 2 0 23 Silvestrosaurus 0 0 0 0 0 2 0 24 Corosaurus 0 0 0 0 0 0 0 2 0 25 Cymatosaurus 0 0 0 2 0&1 1 2 0&1 2 6 Germanosaurus 0 1 0 1 0 1 2 0 27 Pistosaurus 0 0 0 0 2 1 1 2 0 28 Placodus 0 1 0 1 0 0 0 2 1 "Ceresiosaurus," Lariosaurus, and "Silvestro- saurus"), and in all 10 trees, Lariosaurus valce- resii, "Ceresiosaurus'''' calcagnii, and "Silvestro- saurus" buzzii from a monophyletic group (inter- nally unresolved in the strict consensus tree), which in turn falls into an unresolved trichotomy with Lariosaurus balsami and specimen pvhr 1 (described as Lariosaurus curionii n. sp. below) in the strict consensus tree. In six out of these 10 trees, Lariosaurus balsami is the sister taxon of specimen pvhr 1; these two in turn are the sister group to a second lariosaur clade within which "Ceresiosaurus" calcagnii is the sister taxon to Lariosaurus valceresii plus "Silvestrosaurus" buzzii. Tree topology of the 50% majority rule consensus tree is: ((balsami, pvhr 1) (calcagnii (buzzii, valceresii))). implementation of identical search options but treating character 27 as unor- dered yielded five MPTs (TL = 309; CI = 0.647, RI = 0.747), with identical lariosaur interrelation- ships in the strict consensus and 50% majority rule consensus trees. In a second analysis, all 26 taxa were treated as the monophyletic ingroup (Reptilia) rooted on an all-0-ancestor. Heuristic search settings were identical, and of all multistate characters, only character 27 was treated as ordered. All characters were informative. One hundred replications yield- ed a total of 10 MPTs, with TL = 479, CI = 0.630, and RI = 0.762. Lack of resolution was restricted to archosauromorph taxa and lariosaurs. All 10 trees again support the monophyly of lar- iosaurs (including "Ceresiosaurus," Lariosaurus, and "Silvestrosaurus"). Within lariosaurs, Lario- saurus valceresii, "Ceresiosaurus" calcagnii, and "Silvestrosaurus" buzzii again form a monophy- letic group (internally unresolved in the strict con- sensus tree), which in turn falls into an unresolved trichotomy with Lariosaurus balsami and speci- men pvhr 1 in the strict consensus tree (Fig. 19). In six out of these 10 trees, Lariosaurus balsami is the sister taxon of specimen pvhr 1 ; these two in turn are the sister group to a second lariosaur clade within which "Ceresiosaurus" calcagnii is the sister taxon to Lariosaurus valceresii plus "Silvestrosaurus" buzzii (Fig. 20B). Tree topol- ogy of the 50% majority rule consensus tree again is: ((balsami, pvhr 1) (calcagnii (buzzii, valcere- 24 FIELDIANA: GEOLOGY Table 3. Extended. 2 1 1 1 2 1 3 1 4 1 5 1 6 1 7 18 19 20 1 Ancestor 0 0 0 0 0 0 0 0 0 0 2 Captorhinidae 0 0 0 0 0 ? 0 0&3 0 0 3 Testudines 0 0&2 0 0 0 ? 0 4 0 1 4 Araeoscelidia 0 1 0 1 0 0 0 0 0 5 Younginiformes 0 1 0 1 0 0 0 0 0 6 Kuehneosauridae 0 0 0 1 0 0 3 0 7 Rhynchocephalia 0 0 0&1 0&1 0 0&1 0&3 0&2 8 Squamata 0 0&1&2 0&1 0 0 0&1 0&3&4 0&2 9 Rhynchosauria 0 0 0 0 0 1 4 3 1 0 Prolacertiformes 0 1 0 0&1 0 0&1 3&4 0 1 1 Trilophosaurus 0 1 0 0 1 0 4 3 1 2 Choristodera 0 2 0 0 0 0 4 1 1 3 Archosauriformes 0 0&1 0&1 0&1 0&1&2 0&1 0&4 0&2 1 4 Claud iosaurus 0 1 0 0 0 0 0 1 5 Dactylosaurus 0 1 3 0 0 0 0 0 1 6 Serpiano-Neustico 0 1 3 0 0 0 0 0 1 7 Simosaurus 0 2 2 0 0 2 1 1 1 8 Nothosaurus 2 2 0 2 1&2 2&3 1 9 Ceresiosaurus 2 2 0 2 2 2 20 L balsami 2 2 0 2 1&2 1&2 21 L. curionii 2 2 0 2 1 2 2 2 L. valceresii 2 2 0 2 1&2 1&2 2 3 Silvestrosaurus 2 1 0 2 1 0 2 4 Corosaurus 0 0 1 0 1 0 0 1 25 Cymatosaurus 0 2 2 0 1&2 1&2 0 2&3 26 Germanosaurus 1 2 2 0 1 1 1 1 27 Pistosaurus 0 1 2 0 2 1 3 3 28 Placed us 0 0 2 0&1 0 0&2 3 0 Fig. 20. Strict consensus (A) and majority rule consensus tree (B; six out of 10 equally parsimonious trees), indicating lariosaur interrelationships. For further discussion, see text. RIEPPEL: REVISION OF LARIOSAURUS 25 Table 3. Extended. 3 21 2 2 23 24 25 26 2 7 28 29 30 1 Ancestor 0 0 0 0 0 0 0 0 0 0 2 Captorhinidae 0 0 0 0 0 0 0 0 0 3 Testudines 0&1 0 0 0 ? 0 1 0 0 4 Araeoscelidia 0 0 0 0 0 0&1 0 0 0 S Younginiformes 0&1 0 0 0 0 1 0 0 0 6 Kuehneosauridae 1 0 0 0 2 1 1 1 7 Rhynchocephalia 0&1 0&1 1 0 1&2 0 0 1 8 Squamata 0&1 0&1 0 0 2 1 1 ? 9 Rhynchosauria 1 0 1 0 1 1 0 0 1 0 Prolacertiformes 0&1 0 0&1 0 2 1 0&1 1 1 1 Trilophosaurus ? 0 ? 0 0 ? 0 ? 1 2 Choristodera 1 0 0 0 1 1 0&1 0 1 3 Archosauriformes 0&1 0 1 0 1 1 0 0 1 4 Claudiosaurus 1 0 0 0 2 0 0 1 5 Dactylosaurus 1 ? 0 0 2 2 0 0 1 6 Serpiano-Neustico 1 0 0 0 2 2 0 0 1 7 Simosaurus 1 0 0 1 1 2 0 0 1 8 Nothosaurus 1 1&2 0 1 1&2 2 0 0&1 1 9 Ceresiosaurus 1 1&2 0 1 2 2 0 ? 20 L. balsami 1 ? 0 1 2 2 0 ? 21 L. curionii 1 ? ? ? 2 2 0 ? 22 L. valceresii 1 ? 0 1 2 2 0 ? 23 Silvestrosaurus 1 ? 0 1 2 0 ? 24 Corosaurus 1 ? 0 0 2 0 ? 25 Cymatosaurus 1 1 0 0 2 0 1 26 Germanosaurus 1 2 0 1 2 0 ? 27 Pistosaurus 1 ? 0 1 2 0 1 28 Placodus 1 0 0 1 2 0 0 0 sii))). Treating character 27 unordered in an oth- erwise equivalent search (10 replications) yielded 15 MPTs (TL = 478, CI = 0.632, RI = 0.762), with identical lariosaur interrelationships but de- creased resolution among archosauromorph taxa. Listing of synapomorphies for lariosaur taxa was identical in the two searches. The implemen- tation of DELTRAN character optimization will minimize the number of synapomorphies diagnos- tic at any node that will subsequently be lost again within that same clade. For this reason, it will generally indicate synapomorphic characters (character states) at a level of minimal inclusive- ness, rather than maximal inclusiveness as ACC- TRAN character optimization would. Synapomor- phy listing will here be based on DELTRAN char- acter optimization (also in the diagnoses given be- low). The consistency index (CI) for the individual characters is derived from the compre- hensive analysis (second run). Derived characters shared by the genera Germanosaurus, Nothosau- rus, "Ceresiosaurus" Lariosaurus, and "Silves- trosaurus" are: 3(1) [CI = 0.25], 4(1) [CI = 1.0], 11(1) [CI = 1.0], 23(2) [CI = 1.0], 55(1) [CI = 0.5]. Synapomorphies shared by the genera Noth- osaurus, "Ceresiosaurus,'" Lariosaurus, and "Sil- vestrosaurus" are 14(1) [CI = 0.833], 19(2) [CI = 0.714], 35(1) [CI = 0.667], 36(1) [CI = 0.625], 45(1) [CI = 0.5], 51(2) [CI = 0.5], 56(0) [CI = 0.333], 67(1) [CI = 0.5], 74(1) [CI = 0.5], 83(2) [CI = 0.75]. Lariosaurs are diagnosed by the fol- lowing characters: 26(2) [CI = 0.6], 69(1) [CI = 0.667], 73(2) [CI = 0.75], 82(0) [CI = 0.667], 98(0) [CI = 0.6]; 99(3) [CI = 0.667], 101(1) [CI = 0.667], 120(1) [CI = 1.0], 122(1) [CI = 1.0]. "Ceresiosaurus," "Silvestrosaurus," and Lario- saurus valceresii share the following synapomor- phies: 8(0) [CI = 0.6], 77(1) [CI = 0.5], 79(0) [CI = 0.5]. The evidence currently at hand does not sup- port the monophyly of the genus Lariosaurus as currently conceived, including the two species Lariosaurus balsami Curioni, 1847, and Lario- saurus valceresii Tintori and Renesto, 1990. Nor does the available evidence allow the separation of three distinct genera, viz. "Ceresiosaurus," Lariosaurus, and "Silvestrosaurus." Instead, La- riosaurus valceresii, "Ceresiosaurus" calcagnii, 26 FIELDIANA: GEOLOGY Table 3. Extended. 4 31 32 33 34 35 36 37 38 39 40 1 Ancestor 0 0 0 0 0 0 0 0 0 0 2 Captorhinidae 0 0 0 ? 0 0 0 0 0 0 3 Testudines 0 0 0&2 0 0 0 1 1 0 0 4 Araeoscelidia 0 0 0 1 0 0 0 0 ? 0 5 Younginiformes 0 0 0 1 0 0 ? 0 6 Kuehneosauridae 0 0 0 1 0 1 ? 1 7 Rhynchocephalia 0&1 0 0 1 0 0&1 1 0&1 8 Squamata 0 0 0&1&2 0&1 0&1 0&1 1 1 9 Rhynchosauria 1 0 0 0 0 0 1 0 1 0 Prolacertiformes 1 0 0 1 0 0 ? 0 1 1 Trilophosaurus 1 0 2 ? 0 ? 0 0 1 2 Choristodera 1 0 1 1 0 1 ? 0 1 3 Archosauriformes 0&1 0 0&1&2 1 0 0&1 ? 0 1 4 Claudiosaurus 0 0 0 ? 0 0 0 0 ? 0 1 5 Dactylosaurus 2 0 0 ? 0 1 0 1 6 Serpiano-Neustico 2 0 0 ? 0 1 0 1 7 Simosaurus 2 0 1 1 0 0 0 0 0 1 8 Nothosaurus 2 0 0&1 1 0 0 0 1 9 Ceresiosaurus 2 0 0 1 0 0 0 20 L. balsami 2 0 0 1 0 ? 0 21 L. curionii 2 0 0 1 0 ? 0 22 L. valceresii 2 0 0 1 0 ? 0 23 Silvestrosaurus 2 0 0 1 0 ? 0 24 Corosaurus 1 1 1 1 0 0 1 0 25 Cymatosaurus 1 1 1 ? 0 0&1 0 ? 0 26 Germanosaurus ? ? ? ? ? 0 0 ? 0 27 Pistosaurus 1 ? 1 ? 0 1 0 1 0 28 Placodus 1 0 0 1 0 0 1 1 0 and "Silvestrosaurus" buzzii group in a mono- phyletic clade (itself unresolved), which in turn falls into an unresolved trichotomy with Lario- saurus balsami and pvhr 1 in the strict consensus tree. As shown in Figure 20, the genus Lariosaurus as currently conceived is paraphyletic. Monophy- ly of the genus Lariosaurus Curioni, 1847, senior synonym of all three generic names (with L. bal- sami as the genotypical species), requires the in- clusion of all four terminal taxa in that genus, a procedure that renders Ceresiosaurus Peyer, 1931, and Silvestrosaurus Kuhn-Schnyder, 1990, junior synonyms of Lariosaurus. osaurus Munster, 1834, and Lariosaurus Curioni, 1847. Diagnosis — Small to large eosauropterygians with a distinctly constricted snout; temporal re- gion of skull strongly depressed; dorsal exposure of prefrontal reduced; jugal restricted to position behind the orbit without entering the latter's pos- terior margin; premaxillary and anterior dentary fangs present. Distribution — Lower to Upper Triassic, Eu- rope and Israel. Nothosaurinae Nopcsa, 1923 Systematic Paleontology Sauropterygia Owen, 1860 Eosauropterygia Rieppel, 1994b Nothosauridae Baur, 1889 Definition — A monophyletic taxon including the genera Germanosaurus Nopcsa, 1928a,b, Noth- Definition — A monophyletic taxon, including the genera Nothosaurus Munster, 1834, and La- riosaurus Curioni, 1847. Diagnosis — Frontals fused in adult; parietal skull table strongly constricted (at least posteri- orly); occipital crest present; maxillary canines present; dorsal centra not constricted in ventral view; sacral ribs without distal expansion. RIEPPEL: REVISION OF LARIOSAURUS 27 Table 3. Extended. 5 41 42 43 44 45 4 6 4 7 48 4 9 50 1 Ancestor 0 0 0 0 0 0 0 0 0 0 2 Captorhinidae 0 0 0 0 0 1 0 0 0 0 3 Testudines 0&1 0 0 0&1 1 0 0&1 0 0 4 Araeoscelidia 0 0 0 0 0 0 0 0 0 5 Younginiformes 0 0 0 0 0 0 1 0 6 Kuehneosauridae 0 0 0 ? ? 0 0 0 7 Rhynchocephalia 0 0 0 0 0 0 1 0 8 Squamata 0 0 0 0&1 0 0 1 0 9 Rhynchosauria 0 0 0 1 0 0 1 0 1 0 Prolacertiformes 0 0 0 0 0 0 0&1 0 1 1 Trilophosaurus 0 0 0 0 0 0 1 0 1 2 Choristodera 9 0 0 1 0 0 0 0 1 3 Archosauriformes 0&1 0 0 0&1 0&1 0 0&1 0 1 4 Claudiosaurus 0 0 1 0 0 0 0 0 9 1 5 Dactylosaurus ? 0 1 0 1 ? 0 0 1 6 Serpiano-Neustico ? 0 1 0 1 ? 0 0 1 7 Simosaurus 2 0 1 0 0 1 0 1 8 Nothosaurus 2 0 0&1 1 0 1 0 1 9 Ceresiosaurus 2 0 1 1 0 ? 0 20 L. balsami 2 0 1 1 0 9 0 21 L. curionii 2 0 1 1 0 ? 0 22 L valceresii 2 0 1 1 0 9 0 23 Silvestrosaurus 2 0 1 1 0 9 0 24 Corosaurus 9 0 0 9 0 9 1 25 Cymatosaurus ? 0 0 1 0 1 9 0 ? 26 Germanosaurus 9 9 ? 9 ? ? ? 9 9 27 Pistosaurus 9 0 0 ? 0 9 ? ? 9 28 Placodus 1 0 0 1 0 0 1 1 0 Distribution — Lower to Upper Triassic, Eu- rope and Israel. Lariosaurus Curioni, 1847 1847 Lariosaurus, Curioni, p. 166. 1847 Macromirosaurus, Curioni, p. 161. 1854 Lariosaurus, Cornalia, p. 54. 1854 Macromerosaurus, Cornalia, p. 54. 1854 Deirosaurus, Owen, p. 68. 1863 Lariosaurus, Curioni, Pis. 1—3. 1863 Macromerosauro, Curioni, p. 266. 1886 Lariosaurus, Bassani, p. 21. 1886 Macromirosaurus, Bassani, p. 22. 1886 Lariosaurus, Baur, p. 247 ff. 1886 Macromirosaurus, Baur, p. 247 ff. 1886 Lariosaurus, Deecke, p. \l\ff. 1886 Macromerosaurus, Deecke, p. 189/ 1887 Lariosaurus, Zittel, p. 486. 1887 Macromirosaurus, Zittel, p. 486. 1889 Lariosaurus, Lydekker, p. 284. 1889 Macromerosaurus, Lydekker, p. 284. 1889 Macromirosaurus, Lydekker, p. 284. 1890 Lariosaurus, Dames, p. 78 ff. 1891 Eupodosaurus, Boulenger, p. 293. 1898 Lariosaurus, Boulenger, p. Iff. 1898 Macromerosaurus, Boulenger, p. 2. 1898 Palaeosaurus, Boulenger, p. 2. 1924 Lariosaurus, Arthaber, p. 498/ 1924 Macromerosaurus, Arthaber, p. 489/ 1924 Palaeosaurus, Arthaber, p. 499. 1924 Proneusticosaurus (partim), Arthaber, p. 498/ 1927 Lariosaurus, Broili, p. 220/ 1927 Macromerosaurus, Broili, p. 223. 1927 IRhaeticonia, Broili, p. 205 ff. 1928a Lariosaurus, Nopcsa, p. 43. 1928a Macromerosaurus, Nopcsa, p. 43. 1928b Lariosaurus, Nopcsa, p. 173. 1928b Macromerosaurus, Nopcsa, p. 173. 1931 Ceresiosaurus, Peyer, p. 3ff. 1933-34 Lariosaurus, Peyer, p. Aff. 1934 Ceresiosaurus, Kuhn, p. 46. 1934 Lariosaurus, Kuhn, p. 46. 1950 Ceresiosaurus, Peyer, p. 184/ 1955 Ceresiosaurus, Saint-Seine, pp. 424, 428. 28 FIELDIANA: GEOLOGY Table 3. Extended. 6 51 52 83 54 55 56 57 58 59 60 1 Ancestor 0 0 0 0 0 0 0 0 0 0 2 Captorhinidae 0 0 0 0 ? 0 0 0 0 0 3 Testudines 0 1 ? ? ? ? ? 0 0&1 0&2 4 Araeoscelidia 0 1 0 0 0 0 0 0 0 0 S Younginiformes 0 ? 0 0 0 0 0 0 0 6 Kuehneosauridae 0 ? 0 0 0 0 1 1 0 7 Rhynchocephalia 0 1 1 0 0 0 1 0&1 0 8 Squamata 0 1 1 0 0 0 1 0&2 9 Rhynchosauria 0 0 0 ? 0 0 1 0 1 0 Prolacertiformes 0 1 0 0 0 0 0&1 0&2 1 1 Trilophosaurus 0 ? 0 ? 0 0 1 1&2 1 2 Choristodera 0 1 0 0 0 0 0 1 1 3 Archosauriformes 0 1 0 0 0 0 0&1 0&1&2 1 4 Claud iosaurus 0 1 0 0 0 0 0 ? 0 1 5 Dactylosaurus 0 ? 0 0 0 0 0 1 6 Serpiano-Neustico 0 ? 0 0 0 0 0 1 7 Simosaurus 0 1 0 1 0 2 1 1 8 Nothosaurus 2 1 0 1 0 2 1 1 9 Ceresiosaurus 2 1 0 1 0 2 1 20 L balsami 2 1 0 1 0 2 1 2 1 L. curionii 2 1 0 1 0 2 1 22 L. valceresii 2 1 0 1 0 2 1 23 Silvestrosaurus 2 1 0 1 0 2 1 24 Corosaurus 1 ? 0 1 0 1 0 2 5 Cymatosaurus 2 1 0 1 0 1 1 26 Germanosaurus ? ? 0 1 1 1 ? ? ? 27 Pistosaurus ? ? 0 1 0 1 1 1 28 Placodus 2 0 0 1 0 1 0 0 0 1955 Lariosaurus, Saint-Seine, p. 428. 1955 Macromerosaurus, Saint-Seine, p. 428. 1956 Ceresiosaurus, Huene, p. 387. 1956 Lariosaurus, Huene, p. 386. 1956 Ceresiosaurus, Romer, pp. 410, 662. 1956 Lariosaurus, Romer, p. 662. 1964 Lariosaurus, Kuhn, p. 12. 1964 Ceresiosaurus, Kuhn, p. 9. 1966 Ceresiosaurus, Romer, p. 371. 1966 Lariosaurus, Romer, p. 371. 1968 Ceresiosaurus, Miiller, p. 158. 1968 Lariosaurus, Miiller, p. 157. 1970 Ceresiosaurus, Schultze and Wilczew- ski, p. 101 ff. 1970 Lariosaurus, Schultze and Wilczewski, p. 101 # 1987 Lariosaurus, Kuhn-Schnyder, p. 19. 1987 Ceresiosaurus, Schmidt, p. 366. 1987 Lariosaurus, Schmidt, p. 366. 1988 Ceresiosaurus, Carroll, pp. 244, 245, 584, 619. 1988 Lariosaurus, Carroll, pp. 584, 619. 1989b Ceresiosaurus, Rieppel, p. 139# 1989b Lariosaurus, Rieppel, p. 139j^ 1989 Ceresiosaurus, Tschanz, p. 174. 1989 Lariosaurus, Tschanz, p. 156. 1990 Ceresiosaurus, Kuhn-Schnyder, p. 315. 1990 Lariosaurus, Kuhn-Schnyder, p. 315. 1990 Silvestrosaurus, Kuhn-Schnyder, p. 315. 1991 Ceresiosaurus, Storrs, p. 134. 1991 Macromerosaurus, Storrs, p. 136. 1991 Macromirosaurus, Storrs, p. 136. 1991 Lariosaurus, Storrs, p. 136. 1991 Silvestrosaurus, Storrs, p. 139. 1993 Ceresiosaurus, Storrs, p. \19ff. 1993 Lariosaurus, Storrs, p. \19ff. 1993 Silvestrosaurus, Storrs, p. \19ff. 1993 Silvestrosaurus, Renesto, p. 208. 1993b Ceresiosaurus, Rieppel, p. 135. 1993b Lariosaurus, Rieppel, p. 135. 1994a Lariosaurus, Rieppel, p. 347. Type Species — Lariosaurus balsami Curioni, 1847, from the upper Ladinian, Middle Triassic, northern Italy. Definition — A monophyletic taxon including RIEPPEL: REVISION OF LARIOSAURUS 29 Table 3. Extended. 7 6 1 62 63 64 65 6 6 67 68 69 70 1 Ancestor 0 0 0 0 0 0 0 0 0 0 2 Captorhinidae 0 0 0 0 ? 0 0 0 0 0 3 Testudines 1 0&1 0 0 0 0 0 0 0 4 Araeoscelidia 0 0 0 ? 0 0 0 0 0 5 Younginiformes 0 0 0 0 0 0 0 0 0 6 Kuehneosauridae 1 1 0 7 1 0 0 0 1 7 Rhynchocephalia 0&1 0 1 0 0 0 0 0 0 8 Squamata 1 0 0&1 0 0 0 0 0 0&1 9 Rhynchosauria 0 0 0 7 0 0 0 0 0&1 1 0 Prolacertiformes 0&1 0&1 0 7 0 0 0 0 0 1 1 Trilophosaurus 0 0 0 7 0 7 0 0 0 1 2 Choristodera 1 0 0 1 0 0 0 0 0 1 3 Archosauriformes 0&1 0&1 0 0 1 0 0 0 0&1 1 4 Claudiosaurus 0 0 0 ? 0 0 0 0 0 1 5 Dactylosaurus 1 0 0 1 0 1 6 Serpiano-Neustico 1 0 0 1 0 1 7 Simosaurus 1 0 0 0 0 1 1 8 Nothosaurus 1 0 0 0&1 0 1 9 Ceresiosaurus 1 0 0 1 0 20 L. balsami 1 0 0 1 0 21 L. curionii 1 0 0 1 7 22 L. valceresii 1 0 0 1 0 23 Siivestrosaurus 1 0 0 1 0 24 Corosaurus 1 0 0 0 1 0 1 25 Cymatosaurus 1 ? 0 0 0 7 7 26 Germanosaurus ? 7 ? ? 7 7 ? 7 7 7 27 Pistosaurus 7 7 ? 0 0 1 0 7 28 Placodus 1 1 1 0 0 1 0 0 0 1 the species balsami, buzzii, calcagnii, curionii, and valceresii. Diagnosis — Small to large nothosaurs; zyg- apophyseal pachyostosis present; four or more sa- cral ribs; interclavicle of rhomboidal (triangular) shape without any trace of a posterior stem; dorsal wing of ilium reduced to stout process; obturator foramen open in adult; ulna broadened at middi- aphysis; radius somewhat shorter than ulna; hy- perphalangy present in manus. Distribution — Uppermost Anisian and Ladin- ian; southern and western Europe. Comments — Curioni (1847) published a plate showing the mirror image of a specimen he de- scribed under the name Macromirosaurus Plini (p. 161). Later in the text (Curioni, 1847, p. 166), he introduced the name Lariosaurus balsami to refer to the "rettile della famiglia dei Paleosauri" described and figured, but not named, by Balsa- mo-Crivelli (1839). Baur (1886), Deecke (1886), and Lydekker (1889) list Macromirosaurus (Mac- romerosaurus) as a valid taxon. Zittel (1887) con- sidered Macromirosaurus plinii a juvenile of La- riosaurus balsami, a view accepted by Boulenger (1898), and most subsequent workers (e.g., Ar- thaber, 1924). Peyer (1933-1934) reviewed in de- tail the controversy surrounding these taxon names (see also Rieppel, 1987), and concluded that Lariosaurus must have priority over Macro- mirosaurus (Macromerosaurus) because the latter species was described in 1847, whereas the first genus name refers to a specimen already de- scribed and figured in 1839 (for a similar view, see Storrs, 1991). An isolated sacrum came from the Partnach- schichten (Ladinian) of the Gailtaler Alps (Aus- tria) and was described as Proneusticosaurus car- inthiacus by Arthaber (1924, p. 509), but was re- ferred to Lariosaurus by Zapfe and Konig (1980). Broili (1927) described a complete sauropte- rygian skeleton from the Arlbergschichten (Ladin- ian) of Vorarlberg (Austria) as Rhaticonia roth- pletzi. The holotype and only known specimen can no longer be located today (destroyed in World War II, P. Wellnhofer, personal communi- cation). Peyer (1933-1934) considered the taxo- nomic affinities of Rhaeticonia unresolved, but to judge from the illustration of the specimen (Broili, 30 FIELDIANA: GEOLOGY Table 3. Extended. 8 71 72 73 74 75 76 77 78 79 80 1 Ancestor 0 0 0 0 0 0 0 0 0 0 2 Captorhinidae 0 0 0 0 0 ? 0 0 0 0 3 Testudines 0 0 0 0 0 1 0 0 0 0 4 Araeoscelidia 0 0 0 0 0 0 0 0 0 0 5 Younginiformes 0 0 0 0 0&1 0&1 1 0 0 0 6 Kuehneosauridae ? 0 0 0 1 ? ? ? ? ? 7 Rhynchocephalia 0 0 0 0 1 1 0 0 0 8 Squamata 0 0 0 0 1 0&1 0 0 0 9 Rhynchosauria 0 0 0 0 0 1 0 0 0 1 0 Prolacertiformes 0 0 0 1 1 0 0 0 1 1 Trilophosaurus 0 0 0 ? 1 0 0 0 1 2 Choristodera 0 1 0 0 1 1 0 0 1 3 Archosauriformes 0 0&2 0 0&1 1 0 0 0 1 4 Claud iosaurus 0 0 0 1 1 0 0 0 1 5 Dactylosaurus 0 1 0 0 1 1 1 6 Serpiano-Neustico 1 1 0 0 1 0 1 7 Simosaurus 0 1 0 0 0 1 1 8 Nothosaurus 0&1 1 0&1 0&1 1 1 9 Ceresiosaurus 0 2 0 1 0 20 L balsami 0&1 2 0 0 1 21 L. curionii 1 ? ? ? 0 1 22 L. valceresii 0 2 0 ? ? ? 23 Silvestrosaurus 0 ? 0 1 0 0 24 Corosaurus 0 1 0 1 1 0 1 25 Cymatosaurus ? 0 ? ? 0 ? ? ? ? 2 6 Germanosaurus ? ? ? ? ? ? ? ? ? 27 Pistosaurus 0 ? ? ? ? ? ? ? 28 Placodus 0 1 0 0 1 1 0 0 1927, PI. 1), Rhaeticonia is another probable ju- nior synonym of Lariosaurus. Boulenger (1891, pp. 292-293) erroneously de- scribed an isolated left foot of Lariosaurus bal- sami from Esino close to Perledo, first described by Curioni (1863, PI. 7, Fig. 1), as a new taxon, Eupodosaurus longobardicus. In correcting his er- ror, Boulenger (1891, p. 407) referred to the cast of Lariosaurus from the same area and deposits kept at the College of Surgeons, London. The cast he mentioned must be a specimen that Owen (1854, p. 68) referred to under the name of Dei- rosaurus italicus, which here is treated as a junior synonym of Lariosaurus balsami. Lariosaurus balsami Curioni, 1847 1847 Lariosaurus balsami, Curioni, p. 161. 1854 Deirosaurus italicus, Owen, p. 68. 1863 Lariosaurus Balsami, Curioni, p. 266. 1886 Macromerosaurus Plini, Baur, p. 247. 1886 Lariosaurus balsami, Bassani, p. 22. 1886 Macromerosaurus Plinii, Bassani, p. 22. 1886 Lariosaurus balsami, Deecke, p. 171 ff. 1886 Macromerosaurus Plinii, Deecke, p. 171# 1887 Lariosaurus balsami, Zittel, p. 485, Figs. 461-462. 1 889 Lariosaurus balsami, Lydekker, p. 284. 1889 Macromerosaurus plinii, Lydekker, p. 284. 1891 Eupodosaurus longobardicus, Boulen- ger, p. 293. 1891 Lariosaurus balsami, Boulenger, p. 407. 1898 Lariosaurus balsami, Boulenger, p. 1 ff., PL 1. 1898 Macromerosaurus plinii, Boulenger, p. 1. 1899 Lariosaurus balsami, Schrammen, PI. 25, Fig. 13. 1923 Lariosaurus balsami, Man am. p. 218 ff., Fig. 1. 1924 Lariosaurus balsami, Arthaber, Figs. 23-29. RIEPPEL: REVISION OF LARIOSAURUS 31 Table 3. Extended. 9 8 1 82 83 84 85 86 87 88 89 90 1 Ancestor 0 0 0 0 0 0 0 0 0 0 2 Captorhinidae 0 0 ? 0 ? 0 1 0 0 0 3 Testudines 0 1 0 0 ? ? 0 0 1 0 4 Araeoscelidia 0 1 0 0 ? 0 1 0 0 0 5 Younginiformes 0 0&1 0 0 ? 0 0 0 0 6 Kuehneosauridae ? ? ? 1 ? 0 0 0 0 7 Rhynchocephalia 0 0 0 ? 0 0 0 0 8 Squamata 0 0&1 0 ? 0 0 0 0 9 Rhynchosauria 0 0 0 ? 0 0 0&1 0 1 0 Prolacertiformes 0 0 ? 0 ? 0 0 0 0 1 1 Trilophosaurus 0 0 0 ? 0 0 0 0 1 2 Choristodera 0 0 0 ? 0 0 0 0 1 3 Archosauriformes 0 0 0 ? 0 0 0&1 0 1 4 Claudiosaurus 0 0 0 ? 0 0 0 0 1 5 Dactylosaurus ? ? 0 0 2 1 6 Serpiano-Neustico 0&1 2 0 0 2 1 7 Simosaurus 1 0 0 2 1 8 Nothosaurus 0&1 2 0 0 2 1 9 Ceresiosaurus 0 2 0 0 2 20 L. balsami 0 2 0 0 2 21 L. curionii 0 2 0 0 2 22 L. valceresii ? ? 0 0 2 23 Silvestrosaurus ? ? 0 0 2 24 Corosaurus 1 1 1 0 1 25 Cymatosaurus ? ? ? ? ? ? 0 ? ? ? 26 Germanosaurus ? ? 9 ? ? ? 0 ? 9 ? 27 Pistosaurus ? ? ? 1 1 1 0 3 ? ? 28 Placodus 1 1 0 ? 1 0 0 1 1924 Proneusticosaurus carinthiacus, Artha- 1976 ber, p. 509, Figs. 34-35. 1927 Lariosaurus balsami, Broili, p. 215, 1980 Fig. 5. 1927 Macromerosaurus Plinii, Broili, p. 215, 1980 Fig. 2. 1928a Proneusticosaurus carinthiacus, Nop- csa, p. 32. 1983a 1933-34 Lariosaurus balsami, Peyer, p. 121, Figs. 1, 3-14; Pis. 31; 32; 33, Figs. 1984 1, 3; 34-37; 38, Figs. 1, la; 40; 41, Fig. 3. 1984 1933-34 Lariosaurus balsami var. plinii, Peyer, p. 121 /, Fig. 2; PI. 41, Fig. 1. " 1987 1934 Lariosaurus balsami, Kuhn, p. 46. 1934 Lariosaurus balsami var. plinii, Kuhn, 1989b p. 46. 1956 Lariosaurus balsami, Huene, p. 386. 1990 1959 Lariosaurus balsami, Kuhn-Schnyder, p. 655. 1989 1964 Lariosaurus balsami, Kuhn, p. 12. 1974 Lariosaurus balsami, Kuhn-Schnyder, 1991 p. 65, Fig. 42. Lariosaurus balsami, Sanz, pp. 547 ff., Figs. 1-6, 10. Lariosaurus cf. balsami, Zapfe and Konig, p. 72. "Proneusticosaurus carinthiacus," Zap- fe and Konig, p. 78, PI. 1, Fig. 1; PI. 2, Fig. 3. Lariosaurus balsami, Sanz, p. 205 ff., Pis. 2, 3A, C, 4, 5A. Lariosaurus balsami, Ticli, p. 69 ff., Figs. 1-3. Lariosaurus cf. balsami, Warch, p. 81/ Lariosaurus balsami, Kuhn-Schnyder, p. 19, Figs. 10-11. Macromirosaurus Plini, Rieppel, p. 140. Lariosaurus balsami, Kuhn-Schnyder, p. 315. Lariosaurus balsami, Tschanz, p. 157. Lariosaurus balsami, Pinna and Teruz- zi, p. 32, figure on p. 33. 32 FIELDIANA: GEOLOGY Table 3. Extended. 10 91 92 93 94 9 5 96 97 98 99 100 1 Ancestor 0 0 0 0 0 0 0 0 0 0 2 CaptorhinkJae 0 0 0 0 0 0 0 0 0 0 3 Testudines 0 0 0 0 081 082 1 0 182 0 4 Araeoscelidia 0 0 0 0 0 0 0 0 0 5 Younginiformes 0 0 0 0 082 0 081 0 0 6 Kuehneosauridae 0 0 0 0 2 1 2 0 0 7 Rhynchocephalia 0 0 0 0 2 0 0 0 0 8 Squamata 0 0 0 0 082 1 0 0 0 9 Rhynchosauria 0 0 0 0 0 1 0 0 0 1 0 Prolacertiformes 0 0 0 0 0 1 182 0 0 1 1 Trilophosaurus 0 0 ? 0 0 1 0 0 0 1 2 Choristodera 0 0 0 0 0&2 1 2 0 0 1 3 Archosauriformes 0 0 0 0&1 0 1 0 0 0 1 4 Claudiosaurus 0 0 1 1 1 1 0 0 0 0 1 5 Dactylosaurus 0 1 0 1 0 0 0 1 3 0 1 6 Serpiano-Neustico 0 1 0 1 0&1 081 0 182 3 081 1 7 Simosaurus 0 1 0 1 1 1 1 2 2 1 1 8 Nothosaurus 0 1 0&1 0&1 1 081 0 2 2 1 1 9 Ceresiosaurus 0 1 1 1 1 1 0 ? 3 1 20 L. balsam i 0 1 1 1 1 1 081 082 3 0 21 L. curionii 0 1 1 1 1 1 0 0 ? ? 22 L. valceresii 0 1 0 1 1 0 0 0 3 0 23 Silvestrosaurus 0 1 0 1 1 1 1 1 3 0 24 Corosaurus 0 1 1 1 1 0 0 2 1 0 25 Cymatosaurus 0 0 0 0 0 0 0 ? ? 0 26 Germanosaurus ? ? ? ? ? ? ? ? ? ? 27 Pistosaurus 0 1 ? 1 1 1 1 2 0 ? 28 Placodus 0 1 1 1 1 0 1 2 1 0 1993 Lariosaurus balsami, Sanz et al., p. 157/, Figs. 8-13. 1993 Lariosaurus balsami, Renesto, p. 199 ff., Fig. 4A. 1994a Lariosaurus balsami, Rieppel, p. 347, Figs. 2-3. Holotype — A large specimen from Perledo represented by the cervical and anterior dorsal re- gion with parts of the forelimbs preserved was first described by Balsamo-Crivelli (1839) and named by Curioni (1847). The specimen was de- stroyed during World War II. A cast is preserved at the Museo Civico di Storia Naturale, Milano. Kuhn-Schnyder (1987) designated a complete specimen from Perledo (Bayerische Staatssamm- lung fur Palaontologie und Historische Geologic bsp AS I 802) as neotype. Locus Typicus — Calcare di Perledo, Perledo- Varenna Formation, upper Ladinian, Perledo above Varenna, Lake Como, northern Italy. Diagnosis — A medium-sized species of Lario- saurus with a temporal fenestra typically between 1.4 and 1.8 times the size of the orbit; marked parietal constriction behind pineal foramen; hu- merus distinctly curved, with reduced deltopec- toral crest; up to six carpal and four tarsal ossifi- cations in the adult; hyperphalangy in manus only. Distribution — Middle Triassic (middle to up- per Ladinian), southern and western Europe. Comments — Lariosaurus lavizzarii Kuhn- Schnyder, 1987 (referred to Lariosaurus balsami in Kuhn-Schnyder, 1974, p. 65), is based on a juvenile specimen and was treated as a subjective junior synonym of Lariosaurus balsami by Tschanz (1989, p. 157). As a juvenile, the speci- men is not diagnostic (see also Renesto, 1993), and Lariosaurus lavizzarii is therefore here con- sidered a nomen dubium. Similarly, the juvenile specimen described by Renesto (1993) is not di- agnostic and cannot be referred to any species of Lariosaurus with certainty. As noted by Renesto (1993), both these juvenile specimens were col- lected in equivalent deposits (Kalkschieferzone) and in close geographic proximity. The Kalk- schieferzone has otherwise yielded the holotype of Lariosaurus valceresii, and it must remain questionable whether these juvenile specimens are RIEPPEL: REVISION OF LARIOSAURUS 33 Table 3. Extended. 11 101 102 103 104 105 106 107 108 109 1 10 1 Ancestor 0 0 0 0 0 0 0 0 0 0 2 Captorhinidae 0 0 0 0 0 0 0 0 0 0 3 Testudines 0 1 0 0 0 0 1 1 1 0 4 Araeoscelidia 0 0 0 0 0 0 0 0 0 0 5 Younginiformes 0 0 0 0 0 0 6 Kuehneosauridae 0 1 0 0 ? 0 7 Rhynchocephalia 0 1 0 0 1 0 8 Squamata 0 1 0 0 1 0 9 Rhynchosauria 0 0 0 0 1 0 1 0 Prolacertiformes 0 0&1 0 0 0 0 1 1 Trilophosaurus 0 0 0 0 0 0 1 2 Choristodera 0 0 0 1 ? 0 1 3 Archosauriformes 0 0 0 1&2 0&1 0 0 1 4 Claudiosaurus 0 0 0 0 0 1 5 Dactylosaurus 0 ? ? ? 0 1 6 Serpiano-Neustico 0&1 2 1 1 7 Simosaurus 0 2 1 1 8 Nothosaurus 0 2 1 1 9 Ceresiosaurus 1 2 1 20 L. balsami 1 2 1 2 1 L. curionii ? 9 ? ? ? ? ? ? 22 L. valceresii ? 2 1 23 Silvestrosaurus 1 2 ? 24 Corosaurus 1 0 1 1 25 Cymatosaurus 1 0 1 ? ? 26 Germanosaurus ? ? ? ? ? 7 ? ? 27 Pistosaurus ? ? 1 ? ? ? ? 28 Placodus 0 1 0 1 1 1 1 0 to be referred to the latter species or to Lariosau- rus balsami (see Renesto, 1993, for further com- ments). Although distinct, the genotypical species La- riosaurus balsami unfortunately is the only one of all lariosaur species that lacks uniquely derived autapomorphies, and it may thus be considered a metaspecies (Archibald, 1994). This may be the reason why all other specimens of Lariosaurus deposited in public repositories (see Appendix II), except for the holotypes of L. buzzii, specimen pvhr 1, of L. valceresii, and of the specimens re- ferred to L. calcagnii, have to be referred to this species. Lariosaurus balsami correspondingly seems to be the most abundant and the most geo- graphically widespread species of its genus. In- terestingly, a congruent pattern is observed in the Serpianosaurus-Neusticosaurus clade of pachy- pleurosaurs from the Alpine Triassic (Ladinian), within which Neusticosaurus pusillus is the most abundant and geographically most widespread of five (perhaps six) diagnosable species. Neverthe- less, some doubt persist as to whether this large assemblage of specimens referred to Lariosaurus balsami might not, in fact, represent two or more separate species. However, as discussed above, there is no morphological feature known to sub- stantiate such supposition other than the absolute number of carpal (and tarsal) ossifications (see also Peyer, 1933-1934). Among the specimens from the Ladinian of northern Italy, the number of carpal (and tarsal) ossifications varies in a pattern that suggests only a very poor correlation of overall size and degree of ossification. This contrasts with observations of both extant (e.g., Rieppel, 1992) and other fossil (Caldwell, 1994, 1996) taxa, where a good cor- relation of the number of carpal (and tarsal) os- sifications with absolute body size is usually ob- served. Using these observations as a basis for the a priori assumption that a strict control of the de- gree of ossification in relation to individual age (and overall size) also existed in lariosaurs, it would seem possible to distinguish two species, one with six, the other with only three carpal os- sifications. Such a conclusion leaves most of the relatively small specimens indistinct with respect to their specific status, neglects the alternative hy- 34 FIELDIANA: GEOLOGY Table 3. Extended. 12 1 11 1 12 1 13 1 14 1 15 1 16 1 17 1 18 1 19 1 20 1 Ancestor 0 0 0 0 0 0 0 0 0 0 2 Captorhinidae 0 0 0 0 0 0 0 0 0 0 3 Testudines 0 0 0&1 1 0 1 1 0 ? 0 4 Araeoscelidia 0 0 0 0 0 0 1 0 0 5 Younginiformes 0 0 0 0 1 0 1 0 0 6 Kuehneosauridae 7 ? ? ? ? ? ? ? ? 0 7 Rhynchocephalia 0 0&1 1 0 1 1 1 0 0 8 Squamata 0 1 1 0 1 1 1 ? 0 9 Rhynchosauria 1 0 1 0 1 1 ? 0 0 1 0 Prolacertiformes 0&1 0&1 1 0 1 0&1 1 0 0 1 1 Trilophosaurus 1 0 1 0 1 1 ? ? 0 1 2 Choristodera 1 0 1 0 1 1 ? ? 0 1 3 Archosauriformes 1 0&1 1 0 1 1 1 0 0 1 4 Claudiosaurus 0 0 0 0 0 0 ? 0 0 1 5 Dactylosaurus ? ? 7 ? ? 7 ? 0 0 0 1 6 Serpiano-Neustico 0 0 1 1 2 0 0 0 0 0 1 7 Simosaurus 0 0 1 1 1 0 0 0 1 0 1 8 Nothosaurus 0 0 1 1 1 0 0 0 1 0 1 9 Ceresiosaurus 0 0 1 1 1 0 0 0 0 20 L. balsami 0 0 1 1 0 0 0 0 0 2 1 L. curionii 7 7 ? ? ? ? ? 0 ? 22 L. valceresii 0 0 1 1 1 0 0 0 0 23 Silvestrosaurus 0 0 ? ? ? ? ? 0 0 24 Corosaurus 0 0 1 1 1 ? ? 0 1 0 2 5 Cymatosaurus ? ? ? ? ? ? ? 0 0 0 2 6 Germanosaurus 7 7 ? ? ? ? ? 0 ? 0 27 Pistosaurus ? 7 7 7 ? ? ? 0 ? 0 28 Placodus 0 0 1 1 2 0 0 0 0 0 pothesis of possible sexual dimorphism (no sexual dimorphism is expressed by humerus proportions in Lariosaurus, in contrast to pachypleurosaurs), and creates the difficulty of explaining, in ecolog- ical terms, how two separate species of very sim- ilar morphology and adult body size coexisted in restricted habitats as are, for example, represented by the deposits at Perledo. The peculiar preservation of the fossils from Montral-Alcover renders it impossible to study the skeletal anatomy of lariosaurs from that lo- cality in detail. Their general anatomy allows their identification as Lariosaurus balsami (Sanz, 1983b), but in view of their occurrence in a sep- arate locality and facies, the possibility still re- mains that these specimens, like the one from the eastern Pyrenees, represent a separate species. Lariosaurus buzzii Tschanz, 1989 1989 Lariosaurus buzzii, Tschanz, p. 157, Figs. 1-8. 1990 Silvestrosaurus buzzii, Kuhn-Schnyder, p. 313# 1990 Silvestrosaurus buzzii, Tintori and Re- nesto, p. 310j^ 1991 Lariosaurus buzzii, Storrs, p. 139. 1993 "Lariosaurus" buzzii, Storrs, p. 179, Fig. 1. 1993 Lariosaurus buzzii, Renesto, p. 208. 1993b Lariosaurus buzzii, Rieppel, p. 135. Holotype — Disarticulated skeleton kept at the Palaontologisches Institut und Museum der Uni- versitat Zurich (pmz T 2804). Locus Typicus — Grenzbitumenzone (Anisian- Ladinian boundary), Point 902, Monte San Gior- gio, Switzerland. Diagnosis — A small species of Lariosaurus with an upper temporal fossa equal in size to the orbit; nasals fused; parietal broad, not distinctly constricted behind the pineal foramen; anterolat- eral corner of clavicle reduced; entepicondylar fo- ramen absent; radius slightly longer than ulna; pachyostosis absent. Distribution — Middle Triassic (Anisian-Ladin- ian boundary), southern Europe. Comments — This species is known from the RIEPPEL: REVISION OF LARIOSAURUS 35 Table 3. Extended. 13 1 21 122 1 Ancestor 0 0 2 Captorhinidae 0 0 3 Testudines 0 0 4 Araeoscelidia 0 0 5 Younginiformes 0 0 6 Kuehneosauridae 0 0 7 Rhynchocephalia 0 0 8 Squamata 0 0 9 Rhynchosauria 0 0 1 0 Prolacertiformes 0 0 1 1 Trilophosaurus 0 0 1 2 Choristodera 0 0 1 3 Archosauriformes 0 0 1 4 Claud iosaurus 0 0 1 5 Dactylosaurus 0 0 1 6 Serpiano-Neustico 0 0 1 7 Simosaurus 1 0 1 8 Nothosaurus 1 0 1 9 Ceresiosaurus 0 1 20 L. balsami 1 1 2 1 L. curionii 1 ? 22 L. valceresii 1 7 23 Silvestrosaurus ? ? 24 Corosaurus ? ? 25 Cymatosaurus ? ? 2 6 Germanosaurus ? ? 27 Pistosaurus ? 9 28 Placodus ? 0 holotype only. The species is unequivocally di- agnosed by uniquely derived autapomorphies such as the relatively small upper temporal fossa, the broad parietal skull table, and the fused nasals. Lariosaurus curionii n. sp. 1985 Lariosaurus balsami, Mazin, p. 168, Figs. 1-8. Holotype — Skull and partial postcranial skel- eton, kept at the Universite Paris VI, Laboratoire de Paleontologie et de Paleoanthropologie, Paris (pvhr 1, original of Mazin, 1985). Locus typicus — Middle Triassic (probably Ladinian), Amelie-les-Bains, eastern Pyrenees, France. Diagnosis — A medium-sized species of Lario- saurus with no rostral constriction; postfrontal small, excluded from the upper temporal fossa by a contact of the parietal with the postorbital; jugal absent; marked parietal constriction behind pineal foramen; dorsal ribs pachyostotic; deltopectoral crest reduced. Distribution — Middle Triassic (Ladinian), southern Europe. Comments — This species is known from the holotype only. The species is unequivocally di- agnosed by uniquely derived autapomorphies such as the absence of the rostral constriction and the exclusion of the postfrontal from the upper temporal fossa. Lariosaurus calcagnii (Peyer), 1931 1931 Ceresiosaurus calcagnii, Peyer, p. 3ff.; Figs. 1-16, 18-22, 29.2, 30-31; Pis. 18-24. 1934 Ceresiosaurus calcagnii, Kuhn, p. 50. 1949 Ceresiosaurus calcagnii, E. v. Huene, p. 118, Figs. 14-16, 18. 1955 Ceresiosaurus calcagnii, Saint-Seine, Figs. 1,7-8. 1956 Ceresiosaurus calcagnii, F v. Huene, p. 387, Fig. 425. 1964 Ceresiosaurus calcagnii, Kuhn, p. 9. 1968 Ceresiosaurus calcagnii, Muller, Figs. 190-191. 1974 Ceresiosaurus calcagnii, Kuhn-Schny- der, p. 62, Figs. 39-40. Holotype — Complete skeleton, specimen A of Peyer (1931), kept at the Palaontologisches Insti- tut und Museum der Universitat Zurich. Locus Typicus — Lower Meridekalke (lower Ladinian), Acqua del Ghiffo near Serpiano, Monte San Giorgio, Switzerland. Diagnosis — A large species of Lariosaurus with the pineal foramen displaced to the posterior extremity of parietal skull table; front limbs much larger than hind limbs in the adult; humerus not constricted in middiaphyseal region in adult; del- topectoral crest reduced; ulna without distinctly broadened proximal head; pubis with slightly con- cave ventral margin; hyperphalangy in pes; height of neural spines increased in anterior caudal re- gion. Distribution — Middle Triassic (Ladinian), southern Europe. Comments — Since Peyer 's (1931) monograph, additional specimens of Lariosaurus calcagnii have been collected (Kuhn-Schnyder, 1974) that document ontogenetic variation and sexual di- morphism, if not taxic diversity. Unfortunately, this material remains inaccessible for study. The 36 FIELDIANA: GEOLOGY diagnosis for L calcagnii given above is likely to change once this new material is described in de- tail. Nevertheless, the species is unequivocally di- agnosed by uniquely derived autapomorphies such as the hyperphalangy in the pes and the heightened neural spines in the proximal caudal region. Lariosaurus valceresii Tintori and Renesto, 1990 1990 Lariosaurus valceresii, Tintori and Re- nesto, p. 314, Figs. 1-7, PI. 1-2. 1993 Lariosaurus valceresii, Renesto, p. 205#, Fig. 4B. Holotype — Complete skeleton, kept at the Mu- seo Civico di Szienze Naturali di Induno Olona (P 500). Locus Typicus — Kalkschieferzone, upper Meri- dekalke (upper Ladinian), Ca del Frate near Vig- giu, Varese, northern Italy. Diagnosis — A medium-sized species of Lario- saurus with an upper temporal fossa twice the size of the orbit; forelimbs somewhat longer than hind limbs; ectepicondylar groove open and distinctly notched; rib pachyostosis absent. Possible hyper- phalangy in pes. Distribution — Middle Triassic (upper Ladini- an), southern Europe. Comments — This species is known from the holotype only. The species is unequivocally di- agnosed by uniquely derived autapomorphies such as the relatively large upper temporal fossa and the notched ectepicondylar groove. Evolution and Paleobiogeography of the Genus Lariosaurus The Nothosauridae is a well-corroborated clade within the Sauropterygia (Eosauropterygia) which, on the basis of present knowledge, is re- stricted to the shallow, warm-water epicontinental seas of the western Pacific (China: Young, 1959, 1960, 1965, 1978) and western Tethyan (Europe and Middle East: Rieppel, 1997; Rieppel & Wild, 1996; Brotzen, 1957) Province. An earlier analy- sis of the stratigraphic and geographic distribution of Eosauropterygia in the Germanic Triassic in- dicated that the Muschelkalk sauropterygians reached the Germanic basin with a marine trans- gression at the time of transition from the upper Buntsandstein (Rot [so2], Scythian) to the lower Muschelkalk (mu,, Anisian) through an eastern gateway (Rieppel & Hagdorn, 1996; Rieppel, 1997; Fig. 21). This scenario will be tested by the projected review of the Chinese nothosaurs. The earliest appearance of the Nothosauridae in the Germanic Triassic coincides with the occur- rence of Germanosaurus (Arthaber, 1924) and Nothosaurus (Kunisch, 1888) in the lower Go- golin layers of the lowermost Muschelkalk of Up- per Silesia. Germanosaurus is known from an iso- lated occurrence (skull only: Rieppel, 1997). Noth- osaurus remains are fragmentary and rare in the basal lower Muschelkalk of the eastern part of the Germanic basin. More abundant and better pre- served Nothosaurus material (undescribed; kept in private collections: Oosterink, 1986; Oosterink & Diepenbroek, 1990) is known from the basal low- er Muschelkalk of the western part of the Ger- manic basin. In the eastern Muschelkalk basin, the abundance of Nothosaurus picks up in the late lower Muschelkalk and basal middle Muschel- kalk, with the appearance of Nothosaurus mar- chicus and an incompletely known, larger species (Rieppel & Wild, 1996). The genus Nothosaurus persists throughout the Germanic Muschelkalk (the Anisian-Ladinian boundary corresponds to the boundary between lower [mo,] and middle [mo2] upper Muschelkalk), and into the Keuper up to the Gipskeuper, i.e., into the uppermost La- dinian (Rieppel & Wild, 1994). Taxonomic diver- sification of the genus Nothosaurus starts to in- crease with the upper Muschelkalk (Rieppel & Wild, 1996). In spite of abundant material, no sau- ropterygian remains diagnostic for the genus La- riosaurus are known from the entire Muschelkalk. Sauropterygians are exceedingly rare in the An- isian of the Alpine Triassic. Singular occurrences are Cymatosaurus in the lower Anisian of the northern Alpine facies (Rieppel, 1995b), as well as scarce pachypleurosaur remains plus a vertebra probably referable to Cymatosaurus from the low- er Anisian of the southern Alpine facies (Rieppel & Hagdorn, 1997). A partial and rather poorly preserved Nothosaurus skeleton from the lower S-charl-Formation of the (eastern) Alpine facies (transition from Anisian to Ladinian: Furrer et al., 1992) may be referred to Nothosaurus marchicus on the basis of skull proportions. The invasion of the (southern) Alpine facies by the genus Notho- saurus at the time of the Anisian-Ladinian bound- ary (Rieppel & Hagdorn, 1997) is further docu- mented by the occurrence of Nothosaurus gigan- RIEPPEL: REVISION OF LARIOSAURUS 37 Fig. 21. Paleogeography of the genera Nothosaurus and Lariosaurus. A, Entry of Sauropterygia into the Germanic basin through the East Carpathian Gate and/or Silesian-Moravian Gate during the basal Anisian. B, Exit of Saurop- terygia from the Germanic basin through the Burgundy Gate at the Anisian-Ladinian boundary to reach the southern Alpine platform and the Spanish Muschelkalk basin. 1, Bohemian Massif; 2, Vindelician Ridge; 3, Central Massif; 4, Germanic (Muschelkalk) basin; 5, Southern Alpine platform; 6, Spanish (Muschelkalk) basin. Paleoreconstructions are those of Marcoux et al. (1993). teus (senior synonym for Paranothosaurus am- sleri Peyer, 1939; see Rieppel & Wild, 1996, for further discussion) and other nothosaur remains (currently not available for study) in the Grenz- bitumenzone of Monte San Giorgio. Although Nothosaurus successfully invaded the Alpine in- traplatform basin facies (Fig. 21), as documented by isolated records from the middle Ladinian Pro- santo Formation (Biirgin et al., 1991) or from the Ladinian of the Province Udine, Italy (Dalla Vec- chia, 1993), it remains a very rare faunal com- ponent in an otherwise abundant fossil record (Furrer, 1995). The Grenzbitumenzone of Monte San Giorgio (Anisian-Ladinian boundary) yielded the first rec- ord of Lariosaurus (Lariosaurus buzzii Tschanz, 1989), sister group of the genus Nothosaurus. Somewhat later, in the lower Ladinian Meride- kalke (Furrer, 1995), Lariosaurus calcagnii makes its first appearance. Lariosaurus becomes abun- dant in the middle and upper Ladinian deposits of the Alpine facies. The type locality for Lariosau- rus balsami is the Calcare di Perledo, Perledo- Varenna Formation, of the upper Ladinian of the southern Alps. The type locality for Lariosaurus valceresii is the Kalkschieferzone of Ca del Frate near Viggiu, northern Italy, again in the upper Ladinian of the southern Alps. The type locality for Lariosaurus curionii n. sp. is the Middle Tri- assic (Ladinian) of Amelie-les-Bains in the east- ern Pyrenees. Other middle to upper Ladinian oc- currences of Lariosaurus (in the northern Alpine 38 FIELDIANA: GEOLOGY facies, and in the Spanish Muschelkalk) are sum- marized above. The stratigraphic and geographic distribution of the genus suggests that Lariosau- rus originated in the Alpine Triassic sometime around the Anisian-Ladinian boundary, i.e., at a time when its sister group, the genus Nothosau- rus, had invaded the Alpine realm. The slightly later appearance of lariosaurs in the Ladinian of the Spanish Muschelkalk and in the eastern Pyr- enees corresponds to the marine reptile speciation and migration scenario reconstructed by Rieppel and Hagdorn (1997): From early Ladinian times onward, the southern Alpine realm was differen- tiated into a patchy facies pattern of deeper ba- sins, carbonate platforms, and intraplatform ba- sins. From this speciation center situated offshore from the main passages to both the Germanic and Spanish Muschelkalk, sauropterygians may have spread over the western Tethys and Peritethys do- main during the Ladinian as long as a high sea level flooded these areas. It is interesting to note (as summarized above) that in those localities where Lariosaurus is frequent, it may occur to- gether with pachypleurosaurs, which share the same phylogenetic and paleobiogeographic histo- ry (Rieppel & Hagdorn, 1997), but not with its sister taxon Nothosaurus. The exception is the rare occurrence of Lariosaurus in the Keuper, which documents the return of the genus from the Alpine into the Germanic Triassic by upper La- dinian times, a distributional pattern that again is congruent with the stratigraphic and geographic occurrence of the pachypleur genus Neusticosau- rus (Rieppel & Hagdorn, 1997). The genus Neus- ticosaurus originated and diversified in the Alpine Triassic, with Neusticosaurus pusillus invading the Germanic Triassic during late Ladinian times. The congruence of the evolutionary pattern ob- served in the genera Neusticosaurus and Lario- saurus extends to the fact that in spite of appre- ciable diversification at the species level, there is one species in both genera {Neusticosaurus pu- sillus and Lariosaurus balsami, respectively) that is the most abundant and, geographically, the most widespread. The lack of geographic and stratigraphic over- lap in the distribution of Lariosaurus and Notho- saurus may reflect similar ecological requirements of the two sister taxa. But as is the case with Noth- osaurus in the Germanic Triassic (Muschelkalk and lower Keuper; Rieppel & Wild, 1996), the species of Lariosaurus segregate into different size classes in the Alpine Triassic. The only known specimen of Lariosaurus buzzii is relative- ly small, and Lariosaurus calcagnii grows to dis- tinctly larger size than Lariosaurus balsami, La- riosaurus curionii n. sp., and Lariosaurus valce- resii. Different adult size presumably indicates different ecological preferences with respect to diet and may reduce competition between other- wise morphologically very similar species, at least as adults. But whereas species of different body size of Nothosaurus are known to show overlap- ping occurrence both geographically and strati- graphically, the only locality where species of Lariosaurus of different body size (L balsami and L calcagnii) are known to co-occur is the Spanish Muschelkalk of Montral-Alcover. Acknowledgments I am very grateful for the help provided by K. Tschanz, Zurich, in the interpretation of Silvestro- saurus and Ceresiosaurus. Urs Oberli kindly pro- vided a cast of the juvenile Lariosaurus balsami kept in the Natural History Museum in Lausanne. F Stojaspal from the Geologische Bundesanstalt, Vienna, made the loan of the holotype of Pro- neusticosaurus cainthiacus possible. Many col- leagues assisted this research by providing free access to specimens in their care. These include: S. Calzada, Museo de Geologia, Barcelona; Joan Cartanya, Centre d'Historia Natural de la Conca de Barbera; T Kress, Museum beim Solenhofer Aktien-Verein; J.-M. Mazin, Universite de Poi- tiers; D. Goujet, Museum National d'Histoire Na- turelle, Paris; A. C. Milner, The Natural History Museum, London; D. Oppliger, Natural History Museum, Basel; G. Pinna, Museo Civico di Storia Naturale, Milano; G. Plodowski, Forschungsinsti- tut und Naturmuseum Senckenberg, Frankfurt a.M.; S. Renesto, Universita degli Studi, Milano; A. Tintori, Universita degli Studi, Milano; F H. Ucik, Landesmuseum fur Karnten, Klagenfurt; P. Wellnhofer, Bayerische Staatssammlung fur Pa- laontologie und historische Geologic Munich; R. Wild, Staatliches Museum fiir Naturkunde, Stutt- gart; and the officials at the Servicio Geologico dTtalia, Ufficio Geologico di Roma. The pains- taking printing of the photographs was done by Kimberly Mazanek of the Department of Photog- raphy at the Field Museum. This study was sup- ported by National Science Foundation grants DEB-9220540 and DEB-94 19675. RIEPPEL: REVISION OF LARIOSAURUS 39 Literature Cited Alafont, L. S. and Sanz, J. 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Helveticosaurus zollingeri PEYER (Reptilia, Diapsida): Skeletal paedomorphosis, func- tional anatomy and systematic affinities. Palaeonto- graphica, A, 208: 123-152. -. 1992. Studies on skeleton formation in reptiles. m. Patterns of ossification in the skeleton of Lacerta vivipara Jacquin (Reptilia, Squamata). Fieldiana: Zo- ology, n.s., 68: 1-25. 1993a. Middle Triassic reptiles from Monte San Giorgio: Recent results and future potential of analysis. In Mazin, J.-M., and G. Pinna, eds., Evolu- tion, Ecology and Biogeography of the Triassic Rep- tiles. Paleontologia Lombarda, n.s., 2: 131-144. 1993b. Status of the pachypleurosauroid Psi- lotrachelosaurus toeplitschi Nopcsa (Reptilia, Saurop- terygia), from the Middle Triassic of Austria. Fieldi- ana: Geology, n.s., 27: 1-17. -. 1994a. Lariosaurus balsami Curioni (Reptilia, Sauropterygia) aus den Gailtaler Alpen. Carinthia II, 104: 345-356. 1994b. Osteology of Simosaurus gaillardoti and the relationships of stem-group Sauropterygia. Fieldiana: Geology, n.s., 28: 1-85. 1994c. The braincase of Simosaurus and Noth- osaurus: Monophyly of the Nothosauridae (Reptilia: Sauropterygia). Journal of Vertebrate Paleontology, 14: 9-23. 1995a. The pachypleurosaur Neusticosaurus (Reptilia, Sauropterygia) from the Middle Triassic of Perledo, Northern Italy. Neues Jahrbuch fiir Geologie und Palaontologie, Monatshefte, 1995(4): 205-216. 1995b. The status of Anarosaurus multiden- tatus Huene (Reptilia, Sauropterygia), from the Lower Anisian of the Lechtaler Alps (Arlberg, Austria). Pa- laontologische Zeitschrift, 69: 287-297. RIEPPEL: REVISION OF LARIOSAURUS 41 . 1997. Revision of the sauropterygian reptile genus Cymatosaurus v. Fritsch, 1894, and the rela- tionships of Germanosaurus Nopcsa, 1928, from the Middle Triassic of Europe. Fieldiana: Geology, n.s., 36: 1-38. Rieppel, O., and H. Hagdorn. 1997. Paleobiogeogra- phy of Middle Triassic Sauropterygia in Central and Western Europe. In J. M. Callaway and E. L. 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Philosophical Transactions of the Royal So- ciety of London, B, 325: 561-670. Sanz, J. L. 1976. Lariosaurus balsami (Sauropterygia, Reptilia) de Estada (Huesca). Estudios Geologicos, 32: 547-567. . 1983a. Consideraciones sobre el genero Pis- tosaurus. El suborden Pistosauria (Reptilia, Saurop- terygia). Estudios Geologicos, 39: 451-458. 1983b. Los Nothosaurios (Reptilia, Sauropte- rygia) Espanoles. Estudios Geologicos, 39: 193-215. 1984. Osteologia comparada de las familias Nothosauridae y Simosauridae (Reptilia, Sauropteryg- ia). Estudios Geologicos, 40: 81-105. Sanz, J. L., L. S. Alafont, and J. J. Moratalla. 1993. Triassic reptile faunas from Spain. In Mazin, J.-M., and G. Pinna, eds., Evolution, Ecology and Biogeog- raphy of the Triassic Reptiles. Paleontologia Lombar- ds n.s., 2: 153-164. Schmidt, S. 1987. Phylogenie der Sauropterygier (Diapsida; Trias). Neues Jahrbuch fur Geologie und Palaontologie, Abhandlungen, 173: 339-375. Schultze, H.-R, and N. Wilczewski. 1970. Ein Notho- sauride aus dem unteren Mittel-Keuper Unterfrankens. Gottinger Arbeiten zur Geologie und Palaontologie, 5: 101-112. Schrammen, A. 1899. 3. Beitrag zur Kenntnis der Nothosauriden des unteren Muschelkalkes in Ober- schlesien. Zeitschrift der Deutschen Geologischen Gesellschaft, 51: 388-408. Schroder, H. 1914. Wirbeltiere der Rudersdorfer Trias. Abhandlungen der Koniglich Preussischen Geolo- gischen Landesanstalt, Neue Folge, 65: 1-98. Seeley, H. G. 1882. On Neusticosaurus pusillus (Fraas), an amphibious reptile having affinities with terrestrial Nothosauria and with marine Plesiosauria. Quarterly Journal of the Geological Society of Lon- don, 38: 350-366. Senn, A. 1924. Beitrage zur Geologie des Alpensiid- randes zwischen Mendrisio und Varese. Eclogae Geo- logicae Helvetiae, 18: 552-632. Storrs, G. W 1991. Anatomy and relationships of Co- rosaurus alcovensis (Diapsida: Sauropterygia) and the Triassic Alcova Limestone of Wyoming. Bulletin of the Peabody Museum of Natural History, 44: 1-151. . 1993. The systematic position of Silvestrosau- rus and a classification of Triassic sauropterygians. Palaontologische Zeitschrift, 67: 177-191. Sues, H.-D. 1987. Postcranial skeleton of Pistosaurus and interrelationships of the Sauropterygia (Diapsida). Zoological Journal of the Linnean Society, 90: 109- 131. Swofford, D. L. 1990. PAUP Phylogenetic Analysis Using Parsimony, Version 3.0. Illinois Natural History Survey, Champaign, 111. Swofford, D. L., and D. P. Begle. 1993. PAUP Phy- logenetic Analysis Using Parsimony, Version 3.1. Laboratory of Molecular Systematics, Smithsonian In- stitution, Washington, D.C. Ticli, B. 1984. Due esemplari di Lariosaurus balsami Curioni presenti nei Musei Civici di Lecco. Natura (Milano), 75: 69-74. Tintori, A., G. Musico, and S. Nardon. 1985. The Triassic fossil fishes localities in Italy. Rivista Italiana di Paleontologia e Stratigrafia, 91: 197-210. Tintori, A., and S. Renesto. 1990. A new Lariosaurus from the Kalkschieferzone (uppermost Ladinian) of Valceresio (Varese, N. Italy). Bollettino della Societa Paleontologica Italiana, 29: 309-319. Tschanz, K. 1989. Lariosaurus buzzii n. sp. from the Middle Triassic of Monte San Giorgio (Switzerland), with comments on the classification of nothosaurs. Pa- laeontographica, A, 208: 153-179. Via Boada, L., J. F. Villalta, and M. Esteban Cerda. 1977. Paleontologia y paleoecologia de los yacimien- tos fosiliferos del Muschelkalk superior entre Alcover y Mont-ral (Montanas de Prades, Provincia de Tarra- gona). Cuadernos Geologfa Iberica, 4: 247-256. Volz, W. 1902. Proneusticosaurus, eine neue Saurop- terygiergattung aus dem untersten Muschelkalk Ob- erschlesiens. Palaeontographica, 49: 121-164. Warch, A. 1979. Perm und Trias der nordlichen Gail- taler Alpen. Carinthia II, Sonderhefte, 35: 1-111. . 1984. Saurier-Fossilfunde in den Gailtaler Al- pen. Carinthia II, 94: 79-90. Wirz, A. 1945. Beitrage zur Kenntnis des Ladinikum im Gebiete des Monte San Giorgio. In Peyer, B., ed., Die Triasfauna der Tessiner Kalkalpen. XI. Abhand- lungen der Schweizerischen Palaontologischen Ge- sellschaft, 56: 1-84. Young, C.-C. 1959. On a new Nothosauria from the Lower Triassic Beds of Kwangsi. Veterbrata Pal- Asiatica, 3: 73-78. . 1960. New localities of sauropterygians in China. Vertebrata PalAsiatica, 4: 82-85. 1965. On the new nothosaurs from Hupeh and Kweichou, China. Vertebrata PalAsiatica, 9: 337-356. 42 FIELDIANA: GEOLOGY . 1978. A nothosaur from Lu-hsi County, Yun- nan Province. Vertebrata PalAsiatica, 16: 222-224. Zapfe, H., and H. KOnig. 1980. Neue Reptilienfunde aus der Mitteltrias der Gailtaler Alpen (Karnten. Os- terreich). Sitzungsberichte der Osterreichischen Aka- demie der Wissenschaften, Mathematisch-naturwis- senschaftliche Klasse, Abt. I, 189: 65-82. Zeeh, S. 1994. The unusual cyclicity of the Triassic (Carnian) Bleiberg facies of the Wetterstein Formation (Drau Range, Austria). Geologische Rundschau, 83: 130-142. Zittel, K. A. V. 1887. Handbuch der Palaeontologie, I. Abtheilung. Palaeozoologie, III. Band. R. Oldenbourg, Miinchen and Leipzig. Appendix I: Character Definitions for the Data Matrix Shown in Table 3 See Rieppel (1994a, 1997) for a complete dis- cussion of characters and for references. 1. Premaxillae small (0) or large (1), forming most of snout in front of external nares. 2. Premaxilla without (0) or with (1) postnarial process, excluding maxilla from posterior margin of external naris. 3. Snout unconstricted (0) or constricted (1). 4. Temporal region of skull relatively high (0) or strongly depressed (1). 5. Nasals shorter (0) or longer (1) than fron- tal(s). 6. Nasals not reduced (0), somewhat reduced (1), or strongly reduced or absent (2). 7. Nasals do (0) or do not (1) enter external naris. 8. Nasals meet in dorsomedial suture (0) or are separated from one another by nasal processes of the premaxillae extending back to the frontal bone(s)(l). 9. Lacrimal is present and enters the external naris (0), or remains excluded from the external naris by a contact of maxilla and nasal (1), or is absent (2). 10. Prefrontal and postfrontal are separated by the frontal along the dorsal margin of the orbit (0), or a contact of prefrontal and postfrontal ex- cludes the frontal from the dorsal margin of the orbit (1). 11. Dorsal exposure of prefrontal large (0) or reduced (1). 12. Preorbital and postorbital region of skull: of subequal length (0), preorbital region distinctly longer than postorbital region (1), or postorbital region distinctly longer (2). 13. Upper temporal fossa absent (0), present and subequal in size or slightly larger than the orbit (1), present and distinctly larger than orbit (2), or present and distinctly smaller than orbit (3). 14. Frontal(s) paired (0) or fused (1) in the adult. 15. Frontal(s) without (0) or with (1) distinct posterolateral processes. 16. Frontal widely separated from the upper temporal fossa (0), narrowly approaches the upper temporal fossa (1), or enters the anteromedial margin of the upper temporal fossa (2). 17. Parietal(s) paired (0), fused in their posterior part only (1), or fully fused (2) in adult. 18. Pineal foramen close to the middle of the skull table (0), weakly displaced posteriorly (1), strongly displaced posteriorly (2), displaced an- teriorly (3), or absent (4). 19. Parietal skull table broad (0), weakly con- stricted (1), strongly constricted (at least posteri- orly) (2), or forms a sagittal crest (3). 20. Postparietals present (0) or absent (1). 21. Tabulars present (0) or absent (1). 22. Supratemporals present (0) or absent (1). 23. The jugal extends anteriorly along the ven- tral margin of the orbit (0), is restricted to a po- sition behind the orbit but enters the latter's pos- terior margin (1), or is restricted to a position be- hind the orbit without reaching the latter's poste- rior margin (2). 24. The jugal extends backward no farther than to the middle of the cheek region (0) or nearly to the posterior end of the skull (1). 25. The jugal remains excluded from (0) or en- ters (1) the upper temporal arch. 26. Postfrontal large and platelike (0), with dis- tinct lateral process overlapping the dorsal tip of the postorbital (1), or postfrontal with reduced lat- eral process and hence more of an elongate shape (2). 27. Lower temporal fossa absent (0), present and closed ventrally (1), or present but open ven- trally (2). 28. Squamosal descends to (0) or remains broadly separated from (1) ventral margin of skull. 29. Quadratojugal present (0) or absent (1). RIEPPEL: REVISION OF LARIOSAURUS 43 30. Quadratojugal with (0) or without (1) ante- rior process. 31. Occiput with paroccipital process forming the lower margin of the posttemporal fossa and extending laterally (0), paroccipital processes trending posteriorly (1), or occiput platelike with no distinct paroccipital process and with strongly reduced posttemporal fossae (2). 32. Squamosal without (0) or with (1) distinct notch to receive distal tip of paroccipital process. 33. Mandibular articulations approximately at level with occipital condyle (0), or displaced to a level distinctly behind occipital condyle (1), or positioned anterior to the occipital condyle (2). 34. Exoccipitals do (0) or do not (1) meet dorsal to the basioccipital condyle. 35. Supraoccipital exposed more or less verti- cally on occiput (0) or exposed more or less hor- izontally at posterior end of parietal skull table (1). 36. Occipital crest absent (0) or present (1). 37. Quadrate with straight posterior margin (0) or quadrate shaft deeply excavated (concave) pos- teriorly (1). 38. Quadrate covered by squamosal and quadra- tojugal in lateral view (0), or quadrate exposed in lateral view (1). 39. Dorsal wing of epipterygoid broad (0) or narrow (1). 40. Lateral conch on quadrate absent (0) or pres- ent (1). 41. Palate kinetic (0) or akinetic (1). 42. Basioccipital tubera free (0) or in complex relation to the pterygoid as they extend ventrally (1) or laterally (2). 43. Suborbital fenestra absent (0) or present (1). 44. Pterygoid flanges well developed (0) or strongly reduced (1). 45. Premaxillae enter internal naris (0) or are excluded (1). 46. Ectopterygoid present (0) or absent (1). 47. Internal carotid passage enters basicranium (0) or quadrate ramus of pterygoid (1). 48. Retroarticular process of lower jaw absent (0) or present (1). 49. Distinct coronoid process of lower jaw ab- sent (0) or present (1). 50. Surangular without (0) or with (1) strongly projecting lateral ridge defining the insertion area for superficial adductor muscle fibers on the lat- eral surface of the lower jaw. 51. Mandibular symphysis short (0), somewhat enforced (1), or elongated and scooplike (2). 52. Splenial bone enters the mandibular sym- physis (0) or remains excluded therefrom (1). 53. Teeth set in shallow or deep sockets (0) or superficially attached to bone (1). 54. Anterior (premaxillary and dentary) teeth upright (0) or strongly procumbent (1). 55. Premaxillary and anterior dentary fangs ab- sent (0) or present (1). 56. One or two caniniform teeth present (0) or absent (1) on maxilla. 57. The maxillary tooth row is restricted to a level in front of the posterior margin of the orbit (0), or extends backward to a level below the pos- terior corner of the orbit and/or the anterior corner of the upper temporal fossa (1), or extends back- ward to a level below the anterior one-third to one-half of the upper temporal fossa (2). 58. Teeth on pterygoid flange present (0) or ab- sent (1). 59. Vertebrae notochordal (0) or nonnotochordal (1). 60. Vertebrae amphicoelous (0), platycoelous (1), or other (2). 61. Dorsal intercentra present (0) or absent (1). 62. Cervical intercentra present (0) or absent (1). 63. Cervical centra rounded (0) or keeled (1) ventrally. 64. Zygosphene-zygantrum articulation absent (0) or present (1). 65. Sutural facets receiving the pedicels of the neural arch on the dorsal surface of the centrum in the dorsal region are narrow (0) or expanded into a cruciform or butterfly-shaped platform (1). 66. Transverse processes of neural arches of the dorsal region relatively short (0) or distinctly elongated (1). 67. Vertebral centrum distinctly constricted in ventral view (0) or with parallel lateral edges (1). 68. Distal end of transverse processes of dorsal vertebrae not increasing in diameter (0) or dis- tinctly thickened (1). 69. Zygapophyseal pachyostosis absent (0) or present (1). 70. Pre- and postzygapophyses do not (0) or do (1) show an anteroposterior trend of increasing inclination within the dorsal and sacral region. 71. Cervical ribs without (0) or with (1) a dis- tinct free anterior process. 44 FIELDIANA: GEOLOGY 72. Pachyostosis of dorsal ribs absent (0) or present (1). 73. The number of sacral ribs is two (0), three (1), or four or more (2). 74. Sacral ribs with (0) or without (1) distinct expansion of distal head. 75. Sacral (and caudal) ribs or transverse pro- cesses sutured (0) or fused (1) to their respective centrum. 76. Cleithrum present (0) or absent (1). 77. Clavicles broad (0) or narrow (1) medially. 78. Clavicles positioned dorsally (0) or antero- ventrally (1) to the interclavicle. 79. Clavicles do not meet in front of the inter- clavicle (0) or meet in an interdigitating antero- medial suture (1). 80. Clavicles without (0) or with (1) anterolat- eral^ expanded corners. 81. Clavicle applied to the anterior (lateral) (0) or to the medial (1) surface of scapula. 82. Interclavicle rhomboidal (0) or T-shaped (1). 83. Posterior process on (T-shaped) interclavicle elongate (0), short (1), or rudimentary or absent (2). 84. Scapula represented by a broad blade of bone (0) or with a constriction separating a ventral glenoidal portion from a posteriorly directed dor- sal wing (1). 85. The Dorsal wing or process of the eosaurop- terygian scapula tapers to a blunt tip (0) or is ven- trally expanded at its posterior end (1). 86. Supraglenoid buttress present (0) or absent (1). 87. One (0) or two (1) coracoid ossifications. 88. Coracoid of rounded contours (0), slightly waisted (1), strongly waisted (2), or with expand- ed medial symphysis (3). 89. Coracoid foramen enclosed by coracoid os- sification (0) or between coracoid and scapula (1). 90. Pectoral fenestration absent (0) or present (1). 91. Limbs short and stout (0) or long and slen- der (1). 92. Humerus rather straight (0) or curved (1). 93. Deltopectoral crest well developed (0) or re- duced (1). 94. Insertional crest for latissimus dorsi muscle prominent (0) or reduced (1). 95. Humerus with prominent (0) or reduced (1) epicondyles. 96. Ectepicondylar groove open and notched an- teriorly (0), open without anterior notch (1), or closed (2) (i.e., ectepicondylar foramen present). 97. Entepicondylar foramen present (0) or ab- sent (1). 98. Radius shorter than ulna (0), longer than ulna ( 1 ), or approximately of the same length (2). 99. Iliac blade well developed (0), reduced but projecting beyond level of posterior margin of ac- etabular portion of ilium ( 1 ), reduced and no lon- ger projecting beyond posterior margin of acetab- ular portion of ilium (2), or absent, i.e., reduced to simple dorsal stub (3). 100. Pubis with convex (0) or with concave (1) ventral (medial) margin. 101. Obturator foramen closed (0) or open (1) in adult. 102. Thyroid fenestra absent (0) or present (1). 103. Acetabulum oval (0) or circular (1). 104. Femoral shaft stout and straight (0) or slen- der and sigmoidally curved (1). 105. Internal trochanter well developed (0) or re- duced (1). 106. Intertrochanteric fossa deep (0), distinct but reduced (1), or rudimentary or absent (2). 107. Distal femoral condyles prominent (0) or not projecting markedly beyond shaft (1). 108. Anterior femoral condyle relative to poste- rior condyle larger and extending further distally (0) or smaller/equisized and of subequal extent distally (1). 109. Perforating artery passes between astragalus and calcaneum (0) or between the distal heads of tibia and fibula proximal to the astragalus (1). 110. Astragalus without (0) or with (1) a proxi- mal concavity. 111. Calcaneal tuber absent (0) or present (1). 1 12. Foot short and broad (0) or long and slender (1). 113. Distal tarsal 1 present (0) or absent (1). 114. Distal tarsal 5 present (0) or absent (1). 115. Total number of tarsal ossifications four or more (0), three ( 1 ), or two (2). 1 16. Metatarsal 5 long and slender (0) or distinct- ly shorter than the other metatarsals and with a broad base (1). 117. Metatarsal 5 straight (0) or hooked (1). RIEPPEL: REVISION OF LARIOSAURUS 45 118. Mineralized sternum absent (0) or present (1). 119. Medial gastral rib element always has only a single (1) lateral process or may have a two- pronged lateral process (1). 120. Ulna slender at middiaphysis (0) or broad- ened at middiaphysis (1). 121. Ulna without (0) or with (1) distinctly broadened proximal head. 122. Hyperphalangy absent (0) or present (1) in manus. Appendix II: Material Included in the Analysis Bayerische Staatssammlung fur Palaontologie und historische Geologie, Munchen: bsp ASI 802 (neotype for Lariosaurus balsami). British Museum (Natural History), London: bmnh R-2880 (cast of Lariosaurus balsami, left pes; original of Boulenger, 1891; the original spec- imen was kept in Milano and was destroyed in World War II); bmnh R-5263 {Lariosaurus bal- sami, cast of original of Mariani, 1923). Forschungsinstitut und Naturmuseum, Frankfurt a.M.: smf R-13 {Lariosaurus balsami, original of Boulenger, 1898). Geologische Bundesanstalt, Wien: Proneustico- saurus carinthiacus (holotype, original of Ar- thaber, 1924; uncatalogued). Landesmuseum fiir Karnten, Klagenfurt: Palaon- tologische Inventarnummer 5410 {Lariosaurus balsami, original of Zapfe & Konig, 1980, PI. 1, Fig. 1). Museo Civico, Lecco: mcl #202, #663 {Lariosau- rus balsami, originals of Ticli, 1984). Museo Civico di Szienze Naturali di Induno Olona: P 500 (holotype of Lariosaurus valce- resii), P 550 {Lariosaurus, original of Renesto, 1993). Museo Civico di Storia Naturale, Milano: mcsnm uncatalogued (cast of holotype of Lariosaurus balsami, first described by Balsamo-Crivelli, 1839); mcsnm uncatalogued (original of Mari- ani, 1923). Museo y Laboratorio de Geologia, Seminario de Barcelona: M-501 {Lariosaurus balsami, orig- inal of Sanz, 1983b, PI. 2, Fig. B); M-504 {La- riosaurus balsami, original of Sanz, 1983b, PI. 4, Fig. A); M-506 {Lariosaurus balsami, orig- inal of Sanz, 1983b, PI. 2, Fig. A); M-507 {La- riosaurus balsami original of Sanz, 1983b, PI. 4, Fig. B). Museum beim Solnhofer Aktien-Verein, Max- berg: uncatalogued {Lariosaurus balsami, orig- inal of Sanz, 1983b, PI. 5, Fig. A). Museum d'Histoire Naturelle, Lausanne: mhnl uncatalogued {Lariosaurus balsami, juvenile). Perledo. Naturhistorisches Museum, Basel: uncatalogued {Lariosaurus calcagnii, adult specimen). Palaontologisches Institut und Museum der Uni- versitat, Zurich: pmz T 2804 (holotype of La- riosaurus buzzii); pmz T 4288 (holotype of La- riosaurus lavizzarii). Servicio Geologico d' Italia, Ufficio Geologico di Roma: ugr #4423 P {Lariosaurus balsami, specimen Curioni V.I.); ugr #4425 P and ugr #4427 P (holotype of Maromirosaurus Plini Curioni, 1947, part and counterpart); ugr #4428 P {Lariosaurus balsami, specimen Cu- rioni VI); UGR #4429 P {Lariosaurus balsami, specimen Curioni VII.I.); ugr #4430 P {Lario- saurus balsami, specimen Curioni V.3.). Universite Paris VI, Laboratoire de Paleontologie et de Paleonthropologie, Paris: pvhr 1 {Lario- saurus balsami, original of Mazin, 1985). 46 FIELDIANA: GEOLOGY A Selected Listing of Other Fieldiana: Geology Titles Available Status of the Pachypleurosauroid Psilotrachelosaurus toeplitschi Nopcsa (Rcptilia. Sauropterygia). from the Middle Triassic of Austria. By Olivier Rieppel. Fieldiana: Geology, n.s.. no. 27. 1993. 17 pi 9 illus. Publication 1448, $10.00 Osteology of Simosaurus gaillardoti and the Relationships of Stem-Group Sauropterygia. By Olivier Rieppel. Fieldiana: Geology, n.s., no. 28, 1994. 85 pages, 71 illus. Publication 1462, $18.00 The Genus Placodus: Systematics, Morphology, Paleobiogeography, and Paleohiology. By Olivier Riep- pel. Fieldiana: Geology, n.s., no. 31, 1995. 44 pages, 47 illus. Publication 1472, $12.00 Pachypleurosaurs (Reptilia: Sauropterygia) from the Lower Muschelkalk, and a Review of the Pachy- pleurosauroidea. By Olivier Rieppel and Lin Kebang. Fieldiana: Geology, n.s., no. 32, 1995. 44 pages, 28 illus. Publication 1473, $12.00 A Revision of the Genus Nothosaurus (Reptilia: Sauropterygia) from the Germanic Triassic, with Com- ments on the Status of Conchiosaurus clavatus. By Olivier Rieppel and Rupert Wild. Fieldiana: Geology, n.s., no. 34, 1996. 82 pages, 66 illus. Publication 1479, $17.00 Revision of the Sauropterygian Reptile Genus Cymatosaurus v. Fritsch, 1894, and the Relationships of Germanosaurus Nopcsa, 1928, from the Middle Triassic of Europe. By Olivier Rieppel. Fieldiana: Geology, n.s., no. 36, 1997. 38 pages, 16 illus. Publication 1484, $11.00 Order by publication number and/or ask for a free copy of our price list. All orders must be prepaid. Illinois residents add current destination tax. All foreign orders are payable in U.S. dollar-checks drawn on any U.S. bank or the U.S. subsidiary of any foreign bank. Prices and terms subject to change without notice. Address all requests to: FIELD MUSEUM OF NATURAL HISTORY Library — Publications Division Roosevelt Road at Lake Shore Drive Chicago, Illinois 60605-2498, U.S.A. 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