Digitized by the Internet Archive in 2012 with funding from Royal Ontario Museum http://archive.org/details/neogondolelliforOOvonb *te, 5/7/v 0/^; A/o ?.0^ & .S^-** ROM Royal Ontario Museum 15 June 1977 ROYAL ONTARIO MUSEUM LIBRARIES 3 1761 0516233 Life Sciences Occasional Paper No. 29 Neogondolelliform Conodonts of Early and Middle Pennsylvanian Age Peter H. von Bitter Department of Invertebrate Palaeontology, Royal Ontario Museum, Toronto, Ontario Glen K. Merrill Department of Geology, College of Charleston, Charleston, South Carolina Abstract Neogondolelliform conodont elements having morphological features identical to those of the cono- dont genus Neogondolella are increasingly being reported from strata of Pennsylvanian age. It has been suggested that Neogondolella, which until now has been considered to be Permian and Triassic in age, is probably polyphyletic. While it is possible to interpret geologically younger species as ho- meomorphs of Early and Middle Pennsylvanian taxa at present without satisfactory generic assign- ment, it is doubtful to us, in the light of known cases of homeomorphy, that homeomorphy of such an exact nature took place. Since we cannot distinguish these two groups morphologically and be- cause phylogenetic lineages have not been convincingly demonstrated for them, at present we con- sider Pennsylvanian neogondolelliform conodonts to be species of Neogondolella, sensu stricto. The irregular occurrence of neogondolelliform conodonts in the Pennsylvanian is believed to reflect en- vironmental restrictions even more stringent than those noted previously for species of Gondolella. Neogondolelliform conodonts appear near the base of the Pennsylvanian and are therefore con- siderably older than the first species of Gondolella. A common ancestor for the two morphologically similar groups has not been found but the possibility remains that species of Gondolella sprang from those of Neogondolella, rather than the reverse, as has been proposed. Introduction Species of Neogondolella Bender and Stoppel (1965) have come to be thought of as Per- mian and Triassic and those of Gondolella Stauffer and Plummer (1932) as primarily of Middle and Late Pennsylvanian age. Indeed, Clark (1972) suggested the phylogenetic de- rivation of a species of Neogondolella, N. bisselli (Clark and Behnken), from a species of Gondolella, which he identified as G. bella Stauffer and Plummer, in the early Wolf- campian. With such a suggested phylogeny it is paradoxical that conodont elements with the morphology of those of species of Neogondolella are increasingly being re- ported from strata of Pennyslvanian age (Table 1). The question arises whether these neogondolelliform conodonts can reason- ably be referred to the genus Neogondolella or whether they are rather exact heterochro- nous homeomorphs of "true" species of Neogondolella and hence should be assigned to a new genus. Materials and Methods Neogondolelliform conodont elements col- lected by G.K.. Merrill from the Lower Penn- sylvanian of Texas and discussed by Merrill and King (1971) were studied. Similar neo- gondolelliform conodont elements from the Pennsylvanian of the Canadian Arctic were examined through the courtesy of Dr. P.K. Bender of Philipps Universitat, Marburg/ Lahn, West Germany. Neogondolelliform conodonts occurring in rocks of Pennsylva- nian age elsewhere have been tabulated in Table 1 and were not examined first hand. Our understanding of species of Gondolella is based not only on the relevant literature, but is also derived from our independent studies of these Pennsylvanian conodonts (von Bit- ter, 1972, 1976; Merrill, 1975). Neogondolelliform Conodonts in the Pennsylvanian Ellison and Graves (1941) in their work on the conodont faunas of the Lower Pennsyl- vanian Dimple Formation of Texas were the first to record a conodont, which we recog- nize as having a neogondolelliform morphol- ogy, from strata of Pennsylvanian age. This and subsequent reports of conodonts inter- preted by us as having this morphology and occurring in the Middle and Lower Upper Carboniferous are summarized in Table 1. With the possible exception of Gondolella fujimotoi Igo and Kobayashi, the types of which are poorly preserved and could repre- sent a species of Gondolella similar to G laevis Kosenko and Kozitskaya, each of these occurrences documents Pennsylvanian elements with the morphology characteristic of species of Neogondolella. Definition of Neogondolella Neogondolella was defined by Bender (1967: 516) as "a conodont genus of the form that develops from the genus Spathognathodus in the lowermost Triassic. . . .According to the principles of the artificial system the genus would be placed in the form-genus Gondolella" [von Bitter's translation]. Sweet (1970; Teichert, Kummel, and Sweet, 1973) gave a more objective definition. He noted that elements of Neogondolella, in contrast to those of [the Sp elements of] Gondolella, have a finely to coarsely pitted platform, a plat- form that is continued around the posterior side of the cusp as a more or less pro- nounced brim, and anteriorly thin growth la- mellae. He further noted that Clark and Mosher (1966) showed that conspicuous dif- ferences in undersurface morphology ex- isted between elements of the two genera. Fi- nally, Sweet (1970) stated that the skeletal apparatus of Gondolella, in contrast to that of Neogondolella, contained elements of more than a single type. Pennsylvanian Neogondolelliform Elements and their Phylogenetic Significance Conodonts from the Morrowan of Texas show all the features (Fig. 1) characteristic of species of Neogondolella. These include the coarsely pitted platform, the distinctive undersurface morphology, and the pro- nounced brim around the posterior side of the element, all of which were given as defi- nitive features by Sweet (in Ziegler, 1973) in his revised diagnosis of Neogondolella. Speci- i £ 00 < u. = < 11 u c E c3 0 a ~D 0 C 01 0 c Crt O 0 < u 1 c E 0 9 ■2 = = c 0> c ifi O 0 ™ -a ttj c Cd > e 0 c < c/j C O cd D D c 0 D s < H X c/5 a o E 5 c m c cd 1-1 '0 1 0 C cd j* v- '5 E 0 E 0 c u O O 0 < Q 2 < Q c Q ^ •0 a O J* 09 O CJ ■0 C JO s 13 u_ S i> c cd 2 i£ c 4) cd N u _o> jeu > 0 O v 3 T3 ^ T3 _«: V c w T3 •O •0 CA O 0 A X z S 5 2 2 H a IC r- 3 I) cr B O -r u -^ —■ CT' '5 LU ! u jD U. O X o I ^ -S ?3 ^3 -S ^ ~3 a ■s: ■5 R 9, S^ •J 'S •2 < "5 5 -*3 -r o -S 'S a -5 2 "S I <£ I 2 »0 in -k 2 -Sf S C3 o i. "« T3 _ r~l + O 0 u $j ON mens from strata of Atokan-Desmoinesian age from the Canadian Arctic show a similar structure to the figured specimens from Texas and could not be distinguished from those of species of Neogondolella by Sweet (pers. comm., 1975) or by von Bitter. The importance of the pitted ultra- sculpture covering the upper surface of the platforms of species of Neogondolella cannot be overemphasized. These pits cover much of the upper surface of elements of every known species of Neogondolella (see for ex- ample Behnken, 1975, pis. 1 and 2; von Bit- ter, 1976, fig. 5), but are either lacking or re- stricted to the lateral margins (von Bitter, 1976) of the corresponding elements, the platform or Sp elements, in species of Gondolella. That is true even in the oldest known fully platformed species of Gondolel- la, G. laevis Kosenko and Kozitskaya [ = Gondolella n. sp. A of Merrill and King, 1971 and G. pulchra of Merrill, 1975, as shown in Fig. 2. This species was a contemporary of Pennsylvanian neogondolelliform conodont species similar to Neogondolella clarki (Koike). The recovery over the years (Table 1), by a number of authors, of neogondolelliform conodont elements seemingly indistinguisha- ble from species of Neogondolella, from strata of Early and Middle Pennsylvanian age, can be interpreted in two ways: a) Species of Neogondolella are not re- stricted to strata of Permian and Trias- sic age, but ranged from the Early Penn- sylvanian to the Triassic. b) Permian and Triassic species of Neogondolella are homeomorphs of Early and Middle Pennsylvanian taxa that at present are without satisfactory generic assignment. Discussion The first interpretation of the irregular occurrences of these Pennsylvanian Neogondolella-hke forms is that they were subject to environmental restrictions similar to those noted for species of Gondolella (Merrill and von Bitter, 1976). Indeed, with no known occurrences of elements like these from rocks of Missourian or Virgilian age worldwide, the restriction would need to be considerably more confining and might in- clude zoogeographic as well as ecologic con- trols. What the nature of these controls might have been is at present unknown, but there is no compelling reason to believe that it was similar to the environmental restraints upon the distribution of species of Gondolel- la, sensu stricto. The second interpretation would be con- sistent with the concept put forward by Sweet {in Ziegler, 1973: 128) that "the group of species herein assigned to Neogondolella may be polyphyletic" and "It is likely that several unnamed stocks are represented by the more or less isolated species here as- signed to Neogondolella". Although Sweet may be correct in his view that species at present assigned to Neogondolella are poly- phyletic, we remain sceptical that homeo- morphy of such an exact nature could have taken place. Even in well-documented in- stances of homeomorphy, as for example that between species of Patrognathus, Clydagnathus, and Cavusgnathus (Austin, 1973), it is important to note that the degree of homeomorphy was never as exact as in the case under discussion. Because we can- not distinguish Pennsylvanian neogondolel- liform conodonts from similar Permian and Triassic forms and because phylogenetic lineages have not been demonstrated for Fig. 1 a-f Neogondolella clarki (Koike), Texas, San Saba Co., Marble Falls Limestone (Morrowan), ROM 30680, 30681. a Oral view, rom 30680. b Enlarged view of anterior portion, ROM 30680. C. Lateral oral view of side of denticle, rom 30680. D. Enlarged view of anterior portion showing anterior brim, rom 30681. E Enlarged view of aboral edge microsculpture, rom 30680. F. Aboral view, rom 30680. them, at present we consider Pennsylvanian neogondolelliform conodonts to represent species of Neogondolella, sensu stricto. Fur- ther study of Pennsylvanian occurrences of neogondolelliform elements may make it possible to demonstrate that the animals in- volved bore more than one kind of element in their apparatuses. In both the Texas and the Canadian Arctic occurrences (Table 1) a few poorly preserved ramiform elements, possibly belonging in the apparatus of a species of Neogondolella, were found associ- ated with the neogondolelliform conodont elements. If Sweet's conclusion (1970; in Ziegler, 1973), since challenged by Kozur (1976), that Permian and Triassic species of Neogondolella possessed an apparatus con- sisting of only a single kind of element, proves to be correct; possession of multiple elements by the Pennsylvanian forms would constitute sufficient ground for removing them to a separate genus. According to Merrill and King (1971), ad- vanced Desmoinesian species of Gondolella, and by extension Missourian ones including Gondolella elegantula Stauffer and Plummer, the type species, were descendants of G. gymna Merrill and King. Depending upon locality, the beds from which G. gymna were recovered are either uppermost Atokan or lowermost Desmoinesian, but in either case, species of Neogondolella appearing near the base of the Pennsylvanian evolved earlier than did species of Gondolella. Since the groups are morphologically much more simi- lar to each other than to other conodonts with which they are associated, it is not un- reasonable to interpret, as has already been done by Clark (1972), that they are phylo- genetically related. A common ancestor for the two groups has not been found but the strong possibility remains that species of Gondolella sprang from species of Neogondolella, rather than the reverse as has been proposed (Clark, 1972). The suggested xaniognathid origin for species of Neogondolella proposed by Sweet (1970; in Ziegler, 1973) will be discussed for the sake of completeness in considering the origin(s) of Neogondolella. Xaniognathus Sweet (1970) was based on ozarkodiniform blade-like conodont elements which were "not closely associated in range and fre- quency of occurrence with any other elements" (Sweet, 1970: 262) and were inter- preted to have been "the only components of the skeletal apparatus of the conodonts that secreted them" (ibid.). The fact that species of both Neogondolella and Xaniognathus were interpreted to have borne elements of only one kind was a strong factor in leading Sweet to suggest a phylogenetic derivation of Neogondolella from Xaniognathus. The proposed xaniognathid origin for species of Neogondolella appears unlikely to us, particularly in light of the conclusion (Kozur, 1976) that species of the latter bore conodont elements of more than one type and that these species had an element makeup directly comparable to that of spec- ies of Gondolella as shown by von Bitter (1972, 1976) and by Merrill (1975). Instead it seems more probable to us that xaniogna- thodiform conodont elements, rather than being ancestors, were in fact biological com- ponents of one or more species of Neogondolella. This suggestion is supported by the similar overall distribution (range) of species of Xaniognathus and Neogondolella (Sweet, 1970, table 1). The difference in frequency noted by Sweet is believed to rep- resent the normal under- and over- representation of ramiform and platform co- nodont elements, respectively, that are corn- Fig. 2 a-e Gondolella laevis Kosenko and Kozitskaya, Illinois, Rock Island Co., Seville locality 1 1 of Merrill and King (1971), "Seville" Limestone Member (Atokan or Desmoinesian), rom 34444. a. Lateral view. B. Enlarged lateral view of anterior denticles. C Enlarged oral view of anterior denticles. d Aboral view. E Enlarged view of basal cavity. mon in Late Palaeozoic conodont faunas (von Bitter, 1972, 1976). It is significant that Sweet (1970: 263) observed that Neogondo- lella carinata (Clark) and some large speci- mens of Xaniognathus eurvatus Sweet shared certain platform characteristics, but that the latter are distinguished from N. carinata by retention of a short posterior process. We be- lieve this to represent a symmetry transition among anatomical associates much like that reported between the Sp and Oz elements of Gondolella denuda Ellison (von Bitter, 1972) and Gondolella gymna Merrill and King (Merrill, 1975). Acknowledgments We are indebted to the staff of the Depart- ment of Invertebrate Palaeontology, Royal Ontario Museum, for their help and cooper- ation. Mrs. LaVerne Russell operated the scanning electron microscope and Miss Joan Burke typed numerous drafts of the manu- script. Acknowledgment is made for the use of the scanning electron microscope in the Royal Ontario Museum, established through a grant from the National Research Council to the Department of Zoology, University of Toronto, for the development of a pro- gramme in systematic and evolutionary zool- ogy- We thank Dr. P.K. Bender of Philipps Universitat, Marburg/Lahn, West Germany, for permitting us to examine conodonts from the Canadian Arctic recovered and being studied by him. We also wish to thank the outside reviewers of this paper for their con- structive criticisms. Literature Cited AUSTIN. R.L 1973 Phylogeny and homeomorphy of cono- donts in the Lower Carboniferous -In Rhodes, F.H.T., ed. Conodont paleozool- ogy. Special Paper, Geological Society of America. 141: 105-116. BEHNKEN. F H 1975 Leonardian and Guadalupian (Permian) conodont biostratigraphy in western and southwestern United States. -Journal of Paleontology, 49(2): 284-315. BENDER. H 1967 Zur Gliederung der Mediterranen Trias II. Die Conodontenchronologie der Mediter- ranen Trias. -Annales Geologiques des pays Helleniques, 19: 465-540. BENDER. H AND D. STOPPEL 1965 Perm-Conodonten. -Geologisches Jahr- buch, 82: 331-364. CLARK. D.L. 1972 Early Permian crisis and its bearing on Permo-Triassic conodont taxonomy. -In Lindstrom, M. and W. Ziegler. eds. Sym- posium on conodont taxonomy. Geolo- gica et Palaeontologica, SB1 : 147-158. CLARK. D.L. AND L C. MOSHER 1966 Stratigraphic, geographic, and evolution- ary development of the conodont genus Gondolella. -Journal of Paleontology, 40(2): 376-394. ELLISON. S.P., JR AND R.W. GRAVES 1941 Lower Pennsylvanian (Dimple Lime- stone) conodonts of the Marathon Re- gion, Texas. -University of Missouri School of Mines and Metallurgy, Techni- cal Series, 14: 1-13. On the division of the Carboniferous of the South Ural by conodonts. [In Russian] -In Furduj, R.S. and V.S. Zanka-Novatsky, eds. Stratigraphy and biogeography of the seas and lands of the Carboniferous of the USSR Territory. The Lenin Order Kiev State Shevchenko University: 104-109. IGO. H. AND F. KOBAYASH1 1974 Carboniferous conodonts from the Itsu- kaichi District, Tokyo, Japan. -Trans- actions, Proceedings of the Palaeontologi- cal Society of Japan, N.S. 96: 41 1-426. FURDUJ. R.S 1975 KOIKE. T 1967 A Carboniferous succession of conodont faunas from the Atetsu Limestone in southwest Japan (Studies of Asiatic cono- donts. Part vi). -Tokyo Kyoiku Daigaku Science Reports, Section C, 93: 279-318. New species of conodonts from the de- posits of the Moskovian Stage in the south-western part of the Donets Basin. [In Russian] -Akademiya Hayk YCCP, Geological Journal, 35(5): 126-133. Paleoecology of Triassic conodonts and its bearing on multielement taxonomy. -In Barnes, C.R., ed. Conodont paleo- ecology. Special Paper, Geological Asso- ciation of Canada, 15: 312-324. LANE. H R AND J.J STRAKA, II 1974 Late Mississippian and Early Pennsylva- nian conodonts Arkansas and Oklahoma. -Special Paper, Geological Society of America, 152: 1-144. KOSENKO. Z A 1975 KOZUR. H. 1976 MERRILL. G.K. 1975 Pennsylvanian conodont biostratigraphy and paleoecology of northwestern Illinois. -Geological Society of America, Micro- form Publication 3: 1-130. MERRILL. O.K. AND C W KING 1971 Platform conodonts from the lowest Pennsylvanian rocks of northwestern Illi- nois. -Journal of Paleontology, 45(4): 645-664. MERRILL. G.K AND PH. VON BITTER 1976 Revision of conodont biofacies nomen- clature and interpretations of environ- mental controls in Pennsylvanian rocks of eastern and central North America. -Royal Ontario Museum Life Sciences Contribution, 108: 1^16. STAUFFER, C.R. AND H.J. PLUMMER 1932 Texas Pennsylvanian conodonts and their stratigraphic relations. -Bulletin, Univer- sity of Texas, 3201: 13-50. SWEET, W C 1970 Uppermost Permian and Lower Triassic conodonts of the Salt Range and Trans- Indus Ranges, West Pakistan. -In Kummel, B. and C. Teichert, eds. Strati- graphic boundary problems: Permian and Triassic of West Pakistan. University of Kansas Department of Geology Special Publication. 4: 207-275. TEICHERT. C. B. KUMMEL AND W.C. SWEET 1973 Permian-Triassic strata, Kuh-E-Ali Ba- shi, Northwestern Iran. -Bulletin, Mu- seum of Comparative Zoology Harvard University, 145(8): 359-472. von bitter, PR neua typica Rhodes. -Royal Ontario Mu- 1972 Environmental control of conodont distri- seum Life Sciences Contribution. 109: bution in the Shawnee Group (Upper 1^44. Pennsylvanian) of eastern Kansas. -The ii . c is n i .11 ZIEGLER. W. ED University of Kansas Paleontological ~ ... en i mt 1973 Catalogue of conodonts, volume 1. Contributions, 59: 1-105. 6 .„-,, -p, f „ , , „ ,, , , -Stuttgart, E. Schweizerbart sche Verlags- 1976 The apparatus of Gondolella sublanceolata , , , ,, n r- ii //- a . u a ii buchhandlune. 504 pp. Gunnell (Conodontophonda, Upper b rt Pennsylvanian) and its relationship to Illi- 10 Suggested citation: Life Sci. Occ. Pap., R. Ont. Mus. 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