FIELDIANA Geology Published by Field Museum of Natural History New Series, No. 7 REVIEW OF THE HATHLYACYNINAE, AN EXTINCT SUBFAMILY OF SOUTH AMERICAN "DOG-LIKE" MARSUPIALS LARRY G. MARSHALL MAY 5 m\ April 30, 1981 Publication 1318 REVIEW OF THE HATHLYACYNINAE, AN EXTINCT SUBFAMILY OF SOUTH AMERICAN "DOG-LIKE" MARSUPIALS FIELDIANA Geology Published by Field Museum of Natural History New Series, No. 7 REVIEW OF THE HATHLYACYNINAE, AN EXTINCT SUBFAMILY OF SOUTH AMERICAN "DOG-LIKE" MARSUPIALS LARRY G. MARSHALL Assistant Curator of Fossil Mammals Department of Geology Field Museum of Natural History Accepted for publication July 11, 1980 April 30, 1981 Publication 1318 Library of Congress Catalog Card No.: 80-69140 ISSN 0096-2651 PRINTED IN THE UNITED STATES OF AMERICA CONTENTS List of Illustrations vi List of Tables viii Abstract 1 Introduction 1 Abbreviations 2 Acknowledgments 2 Systematics 5 Superfamily Borhyaenoidea 5 Family Borhyaenidae 5 Subfamily Hathlyacyninae 5 Patene 6 P. simpsoni 7 P. coluapiensis 13 Procladosictis 16 P. anomala 16 P. erecta (nomen xnnum) 18 Pseudocladosictis 18 P. determinabile (nomen vanum) 18 Pseudonotictis gen. nov. 19 P. pusillus 19 Notictis 24 N. ortizi 24 Perathereutes 26 P. pungens 26 Borhyaenidium 30 B. musteloides 31 B. nggsi sp. nov 37 Sipalocyon 40 S. externa 42 S. gracilis 44 S. obusta 60 Notocynus 63 N. hermosicus 63 Notogale 65 N. mitis 65 N. tenuis (nomen vanum) 72 Cladosictis 73 C. centralis 73 C. patagonica 79 Chasicostylus 95 C. castroi 95 Anatherium 99 A. herrerae sp. nov 103 A. defossus 103 Hathlyacyninae, Indeterminate 108 Summary of Evolution of Hathlyacyninae 108 Literature Cited 117 LIST OF ILLUSTRATIONS 1. Map of South America showing some vertebrate fossil localities 3 2. Map of southern tip of South America showing vertebrate fossil localities .... 4 3. Patene simpsoni Paula Couto, 1952a (Riochican) 7 4. Patene simpsoni Paula Couto, 1952a (Riochican) 8 5. Patene simpsoni Paula Couto, 1952a (Riochican) 9 6. Patene simpsoni Paula Couto, 1952a (Riochican) 10 7. Patene simpsoni Paula Couto, 1952a (Riochican) 11 8. Patene simpsoni Paula Couto, 1952a (Riochican) 13 9. Patene coluapiensis Simpson, 1935 (Casamayoran) 14 10. Patene coluapiensis Simpson, 1935 (Casamayoran) 15 11. Procladosictis anomala Ameghino, 1902b (Mustersan) 16 12. Procladosictis anomala Ameghino, 1902b (Mustersan) 17 13. Pseudonotictis pusillus (Ameghino, 1891c) (Santacrucian) 20 14. Pseudonotictis pusillus (Ameghino, 1891c) (Santacrucian) 22 15. Pseudonotictis pusillus (Ameghino, 1891c) (Santacrucian) 23 16. Pseudonotictis pusillus (Ameghino, 1891c) (Santacrucian) 24 17. Notictis ortizi Ameghino, 1889 (Huayquerian) 25 18. Notictis ortizi Ameghino, 1889 (Huayquerian) 25 19. Perathereutes pungens Ameghino, 1891c (Santacrucian) 27 20. Perathereutes pungens Ameghino, 1891c (Santacrucian) 28 21. Perathereutes pungens Ameghino, 1891c (Santacrucian) 28 22. Borhyaenidium musteloides Pascual & Bocchino, 1963 (Huayquerian) 32 23. Borhyaenidium musteloides Pascual & Bocchino, 1963 (Huayquerian) 34 24. Borhyaenidium musteloides Pascual & Bocchino, 1963 (Huayquerian) 35 25. Borhyaenidium musteloides Pascual & Bocchino, 1963 (Huayquerian) 36 26. Borhyaenidium riggsi sp. nov. (Montehermosan) 37 27. Borhyaenidium riggsi sp. nov. (Montehermosan) 38 28. Borhyaenidium riggsi sp. nov. (Montehermosan) 39 29. Borhyaenidium riggsi sp. nov. (Montehermosan) 40 30. Sipalocyon externa (Ameghino, 1902c) (Colhuehuapian) 41 31. Sipalocyon externa (Ameghino, 1902c) (Colhuehuapian) 42 32. Sipalocyon gracilis Ameghino, 1887 (Santacrucian) 45 33. Sipalocyon gracilis Ameghino, 1887 (Santacrucian) 45 34. Sipalocyon gracilis Ameghino, 1887 (Santacrucian) 46 35. Sipalocyon gracilis Ameghino, 1887 (Santacrucian) 46 36. Sipalocyon gracilis Ameghino, 1887 (Santacrucian) 47 37. Sipalocyon gracilis Ameghino, 1887 (Santacrucian) 48 38. Sipalocyon gracilis Ameghino, 1887 (Santacrucian) 52 39. Sipalocyon gracilis Ameghino, 1887 (Santacrucian) 54 40. Sipalocyon gracilis Ameghino, 1887 (Santacrucian) 55 41. Sipalocyon gracilis Ameghino, 1887 (Santacrucian) 56 42. Sipalocyon gracilis Ameghino, 1887 (Santacrucian) 58 43. Sipalocyon gracilis Ameghino, 1887 (Santacrucian) 59 44. Sipalocyon obusta (Ameghino, 1891c) (Santacrucian) 60 45. Sipalocyon obusta (Ameghino, 1891c) (Santacrucian) 61 46. Sipalocyon obusta (Ameghino, 1891c) (Santacrucian) 61 47. Notocynus hermosicus Mercerat, 1891b (Montehermosan) 64 vi vii 48. Notoq/nus hermosicus Mercerat, 1891b (Montehermosan) 65 49. Notogale mitis (Ameghino, 1897) (Deseadan) 66 50. Notogale mitis (Ameghino, 1897) (Deseadan) 67 51. Notogale mitis (Ameghino, 1897) (Deseadan) 69 52. Notogale mitis (Ameghino, 1897) (Deseadan) 70 53. Notogale mitis (Ameghino, 1897) (Deseadan) 71 54. Notogale mitis (Ameghino, 1897) (Deseadan) 71 55. Notogale mitis (Ameghino, 1897) (Deseadan) 72 56. Cladosictis centralis Ameghino, 1902c (Colhuehuapian) 74 57. Cladosictis centralis Ameghino, 1902c (Colhuehuapian) 75 58. Cladosictis centralis Ameghino, 1902c (Colhuehuapian) 77 59. Cladosictis centralis Ameghino, 1902c (Colhuehuapian) 78 60. Cladosictis patagonica Ameghino, 1887 (Santacrucian) 80 61. Cladosictis patagonica Ameghino, 1887 (Santacrucian) 81 62. Cladosictis patagonica Ameghino, 1887 (Santacrucian) 82 63. Cladosictis patagonica Ameghino, 1887 (Santacrucian) 83 64. Cladosictis patagonica Ameghino, 1887 (Santacrucian) 84 65. Cladosictis patagonica Ameghino, 1887 (Santacrucian) 86 66. Cladosictis patagonica Ameghino, 1887 (Santacrucian) 90 67. Cladosictis patagonica Ameghino, 1887 (Santacrucian) 91 68. Chasicostylus castroi Reig, 1957 (Chasicoan) 96 69. Chasicostylus castroi Reig, 1957 (Chasicoan) 97 70. Chasicostylus castroi Reig, 1957 (Chasicoan) 98 71. Chasicostylus castroi Reig, 1957 (Chasicoan) 99 72. Anatherium herrerae sp. nov. (Colhuehuapian) 100 73. Anatherium herrerae sp. nov. (Colhuehuapian) 101 74. Anatherium defossus Ameghino, 1887 (Santacrucian) 104 75. Anatherium defossus Ameghino, 1887 (Santacrucian) 105 76. Anatherium defossus Ameghino, 1887 (Santacrucian) 106 77. Anatherium defossus Ameghino, 1887 (Santacrucian) 107 78. Anatherium defossus Ameghino, 1887 (Santacrucian) 107 79. Comparison of upper dentitions of various species of Hathlyacyninae showing relative size and proportions of teeth 109 80. Comparison of lower dentitions of various species of Hathlyacyninae showing relative size and proportions of teeth 110 81. Size distribution of various species of Hathlyacyninae as indicated by length of MM 112 82. Size distribution of various species of Hathlyacyninae as indicated by relationship of length and width of M, 114 83. Dendrogram showing probable phylogenetic relationships of the genera and species of Hathlyacyninae 115 LIST OF TABLES 1. Measurements of cheek teeth of Patene simpsoni and P. coluapiensis 12 2. Measurements of cheek teeth of Pseudonotictis pusillus and Notictis ortizi 21 3. Measurements of mandibular rami of Pseudonotictis pusillus and Notictis ortizi . 21 4. Measurements of lower cheek teeth and mandibular rami of Perathereutes pungens 29 5. Measurements of cheek teeth of Borhyaenidium musteloides, B. riggsi sp. nov, and Notocynus hermosicus 33 6. Measurements of mandibular rami of Borhyaenidium musteloides, B. riggsi sp. nov., and Notocynus hermosicus 34 7. Measurements of upper dentition of Sipalocyon externa 43 8. Measurements of mandibular rami of Sipalocyon gracilis 49 9. Statistics for some dimensions of mandibular rami of Sipalocyon gracilis 49 10. Measurements of upper cheek teeth of Sipalocyon gracilis 50 11. Statistics for some upper cheek tooth dimensions of Sipalocyon gracilis 51 12. Measurements of lower cheek teeth of Sipalocyon gracilis 53 13. Statistics for some lower cheek tooth dimensions of Sipalocyon gracilis 54 14. Measurements of cheek teeth and mandibular rami of Sipalocyon obusta 62 15. Measurements of cheek teeth of Notogale mitis 68 16. Measurements of lower cheek teeth of Cladosictis centralis 76 17. Measurements of mandibular rami of Cladosictis patagonica 81 18. Statistics for some dimensions of mandibular rami of Cladosictis patagonica .... 82 19. Measurements of upper cheek teeth of Cladosictis patagonica 88 20. Statistics for some upper cheek tooth dimensions of Cladosictis patagonica 89 21 . Measurements of lower cheek teeth of Cladosictis patagonica 92 22. Statistics for some lower cheek tooth dimensions of Cladosictis patagonica 94 23. Measurements of cheek teeth of Chasicostylus castroi 97 24. Measurements of lower cheek teeth of Anatherium defossus and A. herrerae sp. nov 102 25. Measurements of mandibular rami of Anatherium defossus and A. herrerae sp. nov 103 26. Summary of some diagnostic characters for genera of Hathlyacyninae Ill ABSTRACT Members of the extinct "dog-like" marsupial subfamily HATHLYACYNINAE (Borhyaenidae, Borhyaenoidea) are known from beds of Late Paleocene (Rio- chican) through Pliocene (Montehermosan) age in Argentina and beds of early Oligocene (Deseadan) age in Bolivia. Twelve genera and 18 species are recog- nized: Patene simpsoni Paula Couto, 1952; Patene coluapiensis Simpson, 1935; Pro- cladosictis anomala Ameghino, 1902; Pseudonotictis pusillus (Ameghino, 1891) gen. nov.; Notictis ortizi Ameghino, 1889; Perathereutes pungens Ameghino, 1891; Bor- hyaenidium musteloides Pascual & Bocchino, 1963; Borhyaenidium riggsi sp. nov.; Sipalocyon externa (Ameghino, 1902); Sipalocyon gracilis Ameghino, 1887; Sipalo- cyon obusta (Ameghino, 1891); Notocynus hermosicus Mercerat, 1891; Notogale mitis (Ameghino, 1897); Cladosictis centralis Ameghino, 1902; Cladosictis patagonica Ame- ghino, 1887; Chasicostylus castroi Reig, 1957; Anatherium herrerae sp. nov.; and Anatherium defossus Ameghino, 1887. In addition, Procladosictis erecta Ame- ghino, 1902; Pseudocladosictis determinabile Ameghino, 1902; and Notogale tenuis (Ameghino, 1897) are regarded as nomina vana. The species and genera are distinguished largely on the basis of absolute and relative size differences in the dentition. Such characters as presence or absence of a metaconid; relative size of protocone, talonid, and stylar shelf; spacing differences between C, P„ and P2; and orientation of P, in the jaw relative to other cheek teeth also proved useful in distinguishing these taxa. With regard to dental structure and incisor number, hathlyacynes are the most generalized of known borhyaenids, and early members (i.e., Patene) closely ap- proximate the expected condition of their presumed didelphoid ancestors. The general evolutionary trend within the Hathlyacyninae involved increase in car- nassial specializations resulting in loss of metaconid and reduction in size of protocone, stylar shelf, and talonid. The group has been extremely conservative during its evolutionary history, and structurally the taxa are monotonously alike. Nevertheless, if sheer numbers of individuals and taxa are a gauge, then the Hathlyacyninae was the most successful of the borhyaenid subfamilies. INTRODUCTION This paper presents a detailed systematic revision of an extinct subfamily of South American "dog-like" marsupials, the Hathlyacyninae. The taxonomic history of the Hathlyacyninae is reviewed, the possible phylogenetic relation- ships of the included taxa are discussed, and the group's taxonomy at the generic and specific levels is stabilized. This study represents an attempt to bring to- gether in one place an updated and expanded treatment of these animals. Sys- 2 FIELDIANA: GEOLOGY tematic revisions of other extinct carnivorous marsupial groups in South America are presented elsewhere [Thylacosmilidae (Marshall, 1976b); Borhyaenidae in general and Borhyaeninae in particular (Marshall, 1978); Prothylacyninae (Mar- shall, 1979)]. During the course of this study I was able to examine, firsthand, all pertinent materials, including type and referred specimens. This work includes discussion and description of some new materials, including two new species, but is es- sentially based on a reappraisal of previously known specimens and literature. The fossil localities mentioned below (figs. 1, 2) are shown on maps and are discussed in detail in Marshall (1976c) and in Marshall, Hoffstetter, & Pascual (in press). The chronology and usage of South American Land Mammal Ages follows Marshall, Hoffstetter, & Pascual (in press), which is based largely on the radioisotope time scale in Marshall, Pascual, et al. (1977) and Marshall, Butler, et al. (1979). All measurements are in millimeters (mm) unless indicated oth- erwise. The serial designation for cheek tooth number employed in this study is based on the dental formula P{^, M{^. ABBREVIATIONS Abbreviations used in text, figure captions, and tables of measurements are: C, canine; ca., approximate measurement; CV, coefficient of variation; I, incisor; L, length; M, molar; N, number; OR, observed range of sample; P, premolar; s, standard deviation of sample; x, mean; W, width. The following abbreviations are used for specimens from institutional collec- tions: AC, Amherst College, Amherst, Mass.; AMNH, American Museum of Natural History, New York; BM(NH), British Museum (Natural History), Lon- don; CMNH, Carnegie Museum of Natural History, Pittsburgh; DGM, Divasao de Geologia e Mineralogia do Departamento Nacional da Producao Mineral, Rio de Janeiro, Brazil; FMNH, Field Museum of Natural History, Chicago; MACN, Museo Argentino de Ciencias Naturales "Bernardino Rivadavia," Buenos Aires, Argentina; MLP, Museo de La Plata, La Plata, Argentina; MMP, Museo Municipal de Ciencias Naturales de Mar del Plata "Lorenzo Scaglia," Mar del Plata, Ar- gentina; MNHN, Museum National d'Histoire Naturelle, Paris, France; MNRJ, Museu Nacional e Universidade Federal do Rio de Janeiro, Brazil; PU, Princeton University, Princeton, N.J.; UCMP, University of California Museum of Paleon- tology, Berkeley, Calif.; USNM, United States National Museum, Washington, D.C ACKNOWLEDGMENTS I am indebted to the following individuals for allowing me to study specimens at their respective institutions: D. Baird (PU), R. H. Tedford (AMNH), R. Pascual (MLP), J. Bonaparte (MACN), F. L. de Souza Cunha (MNRJ), L. Price (DGM), A. J. Sutcliff [BM(NH)], R. Hoffstetter (MNHN), M. Coombs (AC), and M. Dawson (CMNH). For many helpful comments on various phases of this study and/or for reading the manuscript, I thank M. C. McKenna, R. Pascual, R. H. Tedford, and W D. Turnbull. The figures of specimens (except figs. 49, 51-55) were drawn by Mar- lene Hill Werner from original specimens and/or epoxy casts. The latter were Fie. 1. Map of South America showing some vertebrate fossil localities (circles) discussed in text. OCEANO PACI FICO 0 50 100 150 200 k Fig. 2. Map of southern tip of South America showing vertebrate fossil localities (circles) discussed in text. MARSHALL: REVIEW OF THE HATHLYACYNINAE 5 made by Mrs. Barbara Waters at UCMR The stereo photographs were made by Ron Testa from epoxy casts. Initial stages of this study were facilitated by support from UCMP for travel and graduate study and by grants no. 1329, 1698, 1943 from the National Geo- graphic Society, Washington, D.C.; its completion was made possible by National Science Foundation grant DEB-7901976. SYSTEMATICS Superfamily BORHYAENOIDEA (Ameghino, 1894, p. 371) Simpson, 1930, p. 9. Diagnosis. — Dental formula IJH, Q, P£i M$; extinct South American "dog- and cat-like" marsupials of small to large size; lack palatal vacuities; transverse canal either rudimentary or absent; strong sagittal and nuchal crests; lunar small and in contact with large magnum; lacrimal bone extends onto rostrum and usually has large tuberosity developed above lacrimal canal which opens within orbit. Known range. — Riochican through Montehermosan. Family BORHYAENIDAE Ameghino, 1894, p. 371 Diagnosis. — Dental formula l£f, C\, P], M}; small to large size; skull dolicho- cephalic to brachycephalic, rostrum robust and well developed; upper and lower C usually large, laniary, and with closed roots in adults; mandibular symphysis typically shallow (may be fused or unfused in adult) and without flange; man- dibular ramus of subequal depth and breadth below molar series and without distinct labial bend posteriorly along ventral edge as in thylacosmilids; masseteric fossa usually shallow; premolars double rooted; molars increase gradually or rapidly in size from M{ to M$; protocone large to very reduced; paracone often reduced; paracone and metacone approximated on M1'3; stylar shelf reduced; talonids large or reduced, and often imperfectly or not basined; metaconids often absent, if present always smaller than paraconids; nasals large and expanded posteriorly; distinct nasal-lacrimal contact; no postorbital bar; basicranial and basifacial planes parallel; basisphenoid and basioccipital processes increase in width posteriorly, neither has a distinct medial keel and both are relatively flat transversely; at suture they form a fairly prominent transverse ridge; pars petrosa of periotic lacks a tympanic process; large hypoglossal, postsquamosal and post- glenoid foramina present. Known range. — Riochican through Montehermosan. Subfamily HATHLYACYNINAE (Ameghino, 1894, p. 382) Kirsch, 1977, p. 112 [Including Acyonidae,1 Ameghino, 1889, p. 894; 1891a, p. 147n; Hathlyacynidae Ameghino, 1894, p. 382; Amphiproviverridae Ameghino, 1894, p. 333n (formally proposed on p. 389); Cladictidae Winge, 1923, p. 77; Cladosictidae Ameghino, 1935, p. 131; Cladosictinae Cabrera, 1927, p. 273) 'The family-group name Acyonidae was formally proposed by Ameghino (1891a, p. 147n) to accommodate Acyon and Sipalocyon. The name first appears in a list of families in Ameghino (1889, p. 894). Trouessart (1898, p. 1215) later recognized this taxon as a 6 FIELDIANA: GEOLOGY Diagnosis. — It C{, Pi M| (when known); small to medium-sized borhyaenids; mandibular rami long, shallow, and generally gracile; symphysis ligamentous and rami never fused in adult; symphysis typically extends posteriorly to point below P3; IM subequal in size; C weakly or moderately developed; P{ much smaller than P| or P^; P2. and Pj either subequal in size or latter is larger; P13 usually have small but distinct posterobasal cusps; molars increase in size from Mj to M4; metaconid present only in earliest forms (Patene); M13 have large, basined talonid (M4 with reduced talonid that may or may not be basined); small but distinct anterobasal cingulum on M2^, weak or absent on M,; Iw of subequal size; M'^with well-developed protocone; paracone well developed and distinct on M1'3, but smaller and fused basally with larger metacone; weak but distinct parastyle on M1"3, increasing in size from M1 to M3; distinct paracingulum connects parastyle with protocone; metacrista moderately well developed; M3 usually with distinct ectoflex, small ectoflex sometimes present on M2; skull dolichocephalic; large ossified auditory bulla (alisphenoid forms anterior two-thirds, pars mas- toidea of periotic forms posterior one-third — Patterson, 1965); ectotympanic has large incisura tympanica dorsally; epitympanic recess rather large and circular; paroccipital process heavy, squat, and blunt; pars petrosa of periotic rather sharply pointed anteriorly; foramen ovale, foramen lacerum posterium, and posterior carotid foramen all large; foramen lacerum medium absent; terminal phalanges uncleft, laterally compressed, and pointed. Known range. — Riochican through Monte hermosan. Patene Simpson, 1935 Patene Simpson, 1935, p. 3. Ischyrodidelphis Paula Couto, 1952b, p. 9. Type of Patene. — Patene coluapiensis Simpson, 1935, p. 3. Type of Ischyrodidelphis. — Ischyrodidelphis castellanosi Paula Couto, 1952b, p. 11. Distribution. — Riochican of Brazil and Casamayoran of Argentina. Diagnosis. — Borhyaenids of small size; M1^ with large, well-developed pro- tocone and basined talon; paracone slightly smaller than and well separated from metacone on M1 3 (both cusps are more external on M1 and medial on M3); metastylar spur weakly developed; M1 3 with distinct but vestigial protoconules subfamily, Acyoninae, and included it with the Borhyaenidae. The last instance in which the family-group name Acyonidae is employed as a valid name appears in Trouessart (1904, p. 176), who recognized it as distinct from the family-group name Borhyaenidae, and in Palmer (1904, p. 877), who included it as a synonym of the family-group name Borhyaenidae. Palmer (1904, p. 877n) noted that "Acyonidae has priority of five years merely by publication in a nominal list, but as Borhyaenidae has come into more general use it is here adopted provisionally." The family-group name Acyonidae has remained unused as a senior synonym in all zoological literature for the last 70 years. During this time, the family-group name Bor- hyaenidae has always been used, and Acyonidae has been ignored by everyone working on members of this family. In addition, Acyon Ameghino, 1887, is a junior synonym of Cladosictis Ameghino, 1887 (Cabrera, 1927, p. 288; this study). A proposal has been sub- mitted to the Commission requesting use of its plenary powers to suppress the family- group name Acyonidae Ameghino, 1889, for the purposes of the Law of Priority, but not for those of the Law of Homonymy, and to place this family-group name on the Official Index of Rejected and Invalid Family-Group Names in Zoology (Marshall, Clemens, et al., 1977, 1978). MARSHALL: REVIEW OF THE HATHLYACYNINAE 7 and metaconules; shallow but distinct ectoflex present on M5; M4with strong parastylar spur, paracone median, metacone represented by basal cuspule; stylar shelf well developed on M1 3; parastyle small but distinct on M1 2, weakly de- veloped on MJ; P} proodont with distinct posterobasal cuspule; trigonids prom- inent and much higher than talonids; metaconid well developed on M2^, smaller on M,; talonids well developed and basined on MM and narrower than trigonids; M,., with well-developed anterobasal cingular shelf; no evidence of diastems between C, P„ and/or P2. Patene simpsoni Paula Couto, 1952a. Figures 3-8; Table 1. Patent simpsoni Paula Couto, 1952a, p. 23, fig. 8A, B; 1961, p. 329, figs. 8-10; 1970, p. 33. Ischyrodidelphis castellanosi Paula Couto, 1952b, p. 11; 1962, p. 140, fig. 1. Type of Patene simpsoni. — MNRJ 1331-V , a right maxillary with P3-M4 (figured by Paula Couto, 1961, figs. 8-9). Type of Ischyrodidelphis castellanosi. — MNRJ 1351-V, a partial right mandibular ramus with roots of P2, P3-M2, and trigonid of M3 present, and alveoli of M, talonid and M< (figured by Paula Couto, 1962, fig. 1A-B). Fig. 3. Patene simpsoni Paula Couto, 1952a (Riochican). MNRJ 1331-V (type), a right maxillary with P3-M4 complete: a, labial; b, occlusal; c, lingual views. Scale = 10 mm. i* ;&**• Fig. 4. Patene simpsoni Paula Couto, 1952a (Riochican). Stereopairs of MNRJ 1331-V (type), a right maxil- lary with P3-M4 complete: a, labial; b, occlusal; c, lingual views. Scale = 10 mm. MARSHALL: REVIEW OF THE HATHLYACYNINAE Fie. 5. Putene simpsoni Paula Couto, 1952a (Riochican). MNRJ 1351-V (type of Ischyrodi- delphis castellanosi Paula Couto, 1952b), a partial right mandibular ramus with roots of P2, P3-M2 and trigonid of M3 present, and alveoli of M3 talonid and M,: a, labial; b, occlusal; c, lingual views. Scale = 30 mm. Hypodigm. — The two types and DGM 324-M, a fragment of a right mandibular ramus with alveoli of P: and roots of P3, anterior root of M„ talonid and anterior root of M2, M3 virtually complete, and roots of M4 (the M3 is figured by Paula Couto, 1952a, fig. 8A, B; 1961, fig. 10); DGM 331-M, part of a left maxilla with alveoli of M1'3 and incomplete alveoli of P3 and M4; DGM 654-M, an isolated right Mv DGM 655-M, an isolated right M3; DGM 656-M, an isolated right M,; DGM 797-M, an isolated right M3; DGM 798-M, an isolated left M,; MNRJ 1332-V, an isolated right M4; MNRJ 1333-V (now AMNH 49804), an isolated left M1; MNRJ 1334-V (now AMNH 49805), an isolated right M2; MNRJ 1335-V, an incomplete isolated M1 or M2; MNRJ 1336-V, an isolated left lower trigonid; MNRJ 1337-V, an isolated left lower M4 trigonid; MNRJ 1338-V , an isolated left lower trigonid; MNRJ 1339-V, an isolated left lower trigonid; MNRJ 1340-V, an isolated left lower trigonid; MNRJ 1341-V, an isolated left M3 trigonid; MNRJ 1342-V, an isolated left lower trigonid; MNRJ 1343-V, an isolated left lower trigonid; MNRJ 1352-V, an isolated right M^ MNRJ 1353-V, an isolated right M: (figured by Paula Couto, 1962, fig. 1C-E); MNRJ 1354-V, an isolated left M^; MNRJ 1425-V, an isolated right Pv- MNRJ 1428-V, an isolated right lower molar trigonid; (DGM 324-M, MNRJ 1332-V, and MNRJ 1335-V are paratypes of P. simpsoni; and MNRJ 1352-V, 1353-V, 1354-V, and 1425-V are paratypes of /. castellanosi). Horizon and locality. — All specimens were collected from fissure deposits in the Itaboraf Formation, Sao Jose de Itaboraf, Brazil. Age. — Riochican . Fig. 6. Patene simpsoni Paula Couto, 1952a (Riochican). Stereopairs of MNRJ 1351-V (type of Ischyrodidelphis castellanosi Paula Couto, 1952b), a partial right mandibular ramus with roots of P2, P3-M2 and trigonid of M3 present, and alveoli of M3 talonid and M4: a, labial; b, occlusal; c, lingual views. Scale = 30 mm. 10 MARSHALL: REVIEW OF THE HATHLYACYNINAE 11 Fie. 7. Patent simpsoni Paula Couto, 1952a (Riochican). DGM 324-M, a fragment of a right mandibular ramus with alveoli of P2 and roots of Pj, anterior root of Mw talonid and anterior root of M2, M3 virtually complete, and roots of M,: a, labial; b, occlusal; c, lingual views. Scale = 20 mm. Diagnosis. — Differs from Patene coluapiensis in being about one-fourth to one- third smaller in linear tooth dimensions and in having relatively larger proto- cones and wider stylar shelf on M1 "\ a larger metacone on M\ and a slightly shallower ectoflex on M\ Comments. — Paula Couto (1952b, p. 11) erected Ischyrodidelphis castellanosi on a partial lower dentition and several isolated cheek teeth. He assigned this species to the subfamily Didelphinae and concluded (1952b, p. 9) that "its closest affinities seem to be with the largest Recent species of the genus Didelphis." I have compared all specimens assigned by Paula Couto to /. castellanosi with the lower dentitions of Patene simpsoni and found them to represent the same species. I therefore formally recognize /. castellanosi as a junior synonym of P. simpsoni. The recognition that these species are synonymous readily explains why Paula Couto did not assign upper cheek teeth to /. castellanosi; they were all assigned to P. simpsoni. In the lower dentition, he assigned complete cheek teeth from M2 forward to /. castellanosi, whereas he assigned complete M3s and M4s to P. simpsoni. Patene simpsoni is the most generalized of known borhyaenoids. Indeed, if more specialized borhyaenoids like cf. Nemolestes sp. were not contemporaneous with it (see Marshall, 1978, p. 27), P. simpsoni would be an ideal prototype for the superfamily. Patene simpsoni is, nonetheless, structurally the most generalized and temporally the oldest of known Hathlyacyninae and may represent the basal stock for the subfamily. £ l-> vo in in en CD CD o On i— O O i-i • ON O tv CN CD CD CD CD • CM CD r^ vOOOOOON t^ in m so m in V l-l a 2 *? in o o 00 00 ON ON s 1 E << X >>>> oc M a. en w H M w w X u R 5 & 5 7, MNRJ 1331- MNRJ 1332- MNRJ 1333- MNRJ 1334- « S3 e .§ 5. s _s 3 a CM X 2 2 < s M w w X o M B E D Qi Qi C 22222 > >> *•* invoooSSS •sCNiinininoNS22S S_2 22 22!,s © !s ! fl vO * in ro rvi «N 06 •-: S ir, 3 ^- e f ^ 3 s <5 en vo in X 3 § i - 3 — — — — ° S ° S\2's - E •G I a. I/} 06 ts! 3 Z «-" ... Z ?Ucu ay I E I 55" 5T ^= a. B 8? I § 2 S S .H 2 g == U a, a. • a 0 s §.2ss ?S 21 22 FIELDIANA: GEOLOGY Fig. 14. Pseudonotictis pusillus (Ameghino, 1891c) (Santacrucian). Stereopairs of MLP 11- 26 (type of Hathliacynus kobyi Mercerat, 1891a), a left mandibular ramus with root of C, P, and P3-M4 complete, and anterior half and posterior root of P2 present: a, labial; b, occlusal; c, lingual views. Scale = 30 mm. If the species pusillus is to be included in any presently recognized genus following arrangements of previous workers, it would have to be placed either in Cladosictis, from which it is certainly distinct and does not belong, or in Sipalocyon as originally proposed by Ameghino. There are sufficient differences, however, between pusillus and species of Sipalocyon to warrant generic separa- tion. For this reason I have proposed the new generic name Pseudonotictis. Pseudonotictis pusillus differs from species of Sipalocyon in being smaller in size, in having a proportionately smaller Pu in lacking a distinct (or less prominent) posterobasal heel on P,.3, in having a relatively and absolutely smaller protocone on upper molars, and in having a more weakly developed canine. Pseudonotictis pusillus is similar in size to the Riochican species Patene simpsoni. These species differ in P. pusillus having a more specialized dentition in the MARSHALL: REVIEW OF THE HATHLYACYNINAE 23 Fie. 15. Pseudonotictis pusillus (Ameghino, 1891c) (Santacrucian). MLP 11-26 (type of Hathlmynus kobyi Mercerat, 1891a), a frag- ment of a right maxillary with alveoli of P- M ; . and a complete M:: a, labial; b, occlusal; c, lingual views. Scale = 5 mm. direction of carnassialization than does P. simpsoni. The primary changes in- volved in such a lineage include reduction in size of the protocone, stylar shelf, talonid, and metacone (latter becoming fused basally with paracone); virtual loss of posterobasal cuspule on Pv loss of metaconid; elongation and tricuspid struc- ture of M,; and an increase in size and importance of postvallum-prevallid shear. Considering the time involved, Riochican to Santacrucian, these changes are minor, and I thus choose to regard P. simpsoni as the Riochican structural ancestor of P. pusillus. Pseudonotictis pusillus is in turn very similar to Notictis ortizi from the Huay- querian. Both species are of similar size, both have virtually identical molar morphology, both have weakly developed canines, and the size, shape, and location of the mental foramina are similar. The premolars in N. ortizi are ab- solutely and relatively smaller than in P. pusillus, and the premolar region of the jaw is more shortened and the teeth crowded, such that the P, is set obliquely in the jaw. These differences are related to shortening of the premolar region of the jaw and are thus the expression of a single basic change. Even taken as a whole, the differences between these species are not great and represent only slight modification or specialization of features seen in P. pusillus. An ancestral- descendant relationship for these taxa seems probable. 24 FIELDIANA: GEOLOGY tT2r*Jii Fig. 16. Pseudonotictis pusillus (Ameghino, 1891c) (Santacru- cian). Stereopairs of MLP 11-26 (type of Hathliacynus kobyi Mer- cerat, 1891a), a fragment of a right maxillary with alveoli of P3- M1, and a complete M2: a, labial; b, occlusal; c, lingual views. Scale = 10 mm. Notictis Ameghino, 1889 Notictis Ameghino, 1889, p. 911; Kraglievich, 1934, p. 62; Reig, 1952, p. 3. Type. — Notictis ortizi Ameghino, 1889, p. 912. Distribution. — "Mesopotamian beds" along rio Parana, Entre Rfos Province, Argentina. Diagnosis. — As for type and only known species. Notictis ortizi Ameghino, 1889. Figures 17, 18; Tables 2, 3. Notictis ortizi Ameghino, 1889, p. 912, pi. 72, fig. 14, pi. 81, fig. 7; 1891b, p. 262; Krag- lievich, 1934, pp. 62-63; Simpson, 1945, p. 42n (as nomen vanum); Reig, 1952, p. 3, fig. 1; Ringuelet, 1953, p. 267. Didelphys curvidens Burmeister, 1891, p. 379, pi. 7, fig. 1. Type. — MACN 3996, a left mandibular ramus with alveoli of C and F^-Mx complete, M2.4 present but broken (figured by Ameghino, 1889, pi. 72, fig. 14; Burmeister, 1891, pi. 7, fig. 1; Reig, 1952, fig. 1). Hypodigm. — Type only. Horizon and locality. — "Piso mesopotamico de la formacion patagonica," "bar- rancas de los alredores de la ciudad del Parana," along the rio Parana, Entre Rios Province, Argentina. Age. — Huayquerian. Fie. 17. Notictis ortizi Ameghino, 1889 (Huayquerian). MACN 39% (type), a left man- dibular ramus with alveoli of C, PpM! complete, and M2A present but broken: a, labial; b, occlusal; c, lingual views. Scale = 20 mm. f^^^W Fie. 18. Notictis ortizi Ame- ghino, 1889 (Huayquerian). Stereopairs of MACN 3996 (type), a left mandibular ra- mus with alveoli of C, P|-M, complete, and M2.4 present but broken: a, labial; b, occlu- sal; c, lingual views. Scale = 30 mm. 25 26 FIELDIANA: GEOLOGY Diagnosis. — Very small size, smallest known species of Huayquerian bor- hyaenid; C weakly developed; P, tiny and set obliquely in jaw; P23 larger and crowded, but roots aligned in same anteroposterior axis; P, separated from P2 by small diastema; P2 and P3 crowded such that posterior alveolus of former and anterior alveolus of latter are confluent; M^-, have small, but basined talonids, well-developed anterobasal cingula, and lingual side of talonid basin slightly higher than labial side; differs from Pseudonotictis pusillus in having relatively larger talonids, in an absolutely shorter premolar region, and smaller P,. Comments. — The type of Notictis ortizi has been redescribed and its taxonomic history discussed by Reig (1952). As demonstrated by Ameghino (1891b, p. 262) and Kraglievich (1934, pp. 62-63), Didelphys curvidens Burmeister (1891, p. 379) and N. ortizi Ameghino (1889, p. 912) were founded on the same specimen, MACN 3996. A second specimen, MACN 565 (cast) originally referred to N. ortizi and figured by Ameghino (1889, pi. 81, fig. 7) and later discussed by Reig (1952, p. 3), is almost certainly a didelphoid. Notictis ortizi very probably evolved from the Santacrucian species Pseudono- tictis pusillus. The probable phylogenetic relationships of these species are dis- cussed in the comments section on P. pusillus. Perathereutes Ameghino, 1891c Perathereutes Ameghino, 1891c, p. 313. Type. — Perathereutes pungens Ameghino, 1891c, p. 313. Distribution. — Santa Cruz Formation, Santa Cruz Province, Argentina. Diagnosis. — As for type and only known species. Perathereutes pungens Ameghino, 1891c. Figures 19-21; Table 4. Perathereutes pungens Ameghino, 1891c, p. 313; 1894, p. 392, fig. 54; 1898, pp. 191, 193, fig. 58d; 1935, p. 108, fig. 23 (caption only). Epanorthus aratae Ameghino, 1889, pi. 1, figs. 10-lOb (partim). Abderites altiramis Ameghino, 1894, p. 340; 1898, p. 186. Type of Perathereutes pungens. — MACN 684, a left mandibular ramus with al- veolus of C, roots of P13, MM complete but worn (figured by Ameghino, 1894, fig. 54; 1898, fig. 58d). Type of Abderites altiramis. — MACN 8250, a fragment of a right mandibular ramus with talonid of M3, anterior alveolus and posterior root of M4 (figured by Ameghino, 1889, pi. 1, figs. 10-10d as Epanorthus aratae). Hypodigm. — Types only. Horizon and locality. — Both types are from the Santa Cruz Formation, Santa Cruz Province, southern Argentina. MACN 684 is from Monte Observacion and was collected by C. Ameghino in 1890-91. MACN 8250 is from La Cueva and was collected by C. Ameghino in 1892-93. Age. — Santacrucian. Diagnosis. — Intermediate in size between Pseudonotictis pusillus and Sipalocyon gracilis; P] small and set at slight oblique angle in jaw and separated from C and P2 by small but distinct diastems; talonid well developed and basined on M,^, but relatively smaller than in Sipalocyon; mandibular ramus exceptionally shallow in depth relative to its length; symphysis extends posteriorly to point below P2.3 contact; C moderately developed as in Sipalocyon; entoconid higher than hypoconid on M^, lower on M4. u B — 5 I Cm " 3 a, a, 2 27 Fig. 20. Perathereutes pungens Ameghino, 1891c (Santacrucian). Stereopairs of MACN 684 (type), a left mandibular ramus with alveoli of C, roots of Pj.3, and Mw complete but worn: a, labial; b, occlusal; c, lingual views. Scale = 40 mm. A* A. ..'j**N*we\ - Tip«» fl.fc$4 Fig. 21. Perathereutes pungens Ameghino, 1891c (Santacrucian). MACN 684 (type), a left mandibular ramus with alveoli of C, roots of Pi.3, and M^ complete but worn: top, occlusal; bottom, lingual views. Scale = 50 mm. 28 E£ 2^ 0> 00 v- cu o T o uS in 00 vO zz uu 29 30 FIELDIANA: GEOLOGY Description. — Three mental foramina occur on type: largest below diastema between P, and P2, a slightly smaller one below P2_3 contact, and one of similar size to latter below Mi_2 contact. The region of the mandibular ramus near the P2 and anterior root of the P3 is covered with secondary bone growth, indicating that this area was either diseased or injured during the life of the animal. Comments. — Abderites altiramis was erected by Ameghino (1894, p. 304) on a fragment of a right mandibular ramus (MACN 8250) that preserves the anterior alveolus and talonid of M3 and roots of M4. Ameghino characterized this species as being almost twice as large as Abderites crassiramis. MACN 8250 is not, how- ever, an abderitine, but a small borhyaenid. Size of the M^ roots and structure of the M3 talonid agree almost perfectly with the type of Perathereutes pungens (MACN 684). The ramus of A. altiramis is slightly shallower and more gracile than in P. pungens, but these differences are minor, and A. altiramis is regarded a junior synonym of P. pungens. MACN 8250 was figured by Ameghino (1889, pi. 1, figs. 10-10b) as Epanorthus aratae. Ameghino (1891c, p. 313) originally placed P. pungens in the family Thylacynidae, but later (1894, p. 392) included it in his group Sparassodonta, family Amphiproviverridae. Perathereutes pungens is similar to Sipalocyon gracilis, although there are impor- tant differences; P. pungens differs from specimens of the latter (i.e., MACN 5938) in being smaller in size, in having Pj set at a sharper oblique angle in jaw and being separated from C and P2 by distinct diastems, and in a proportionately smaller talonid basin, especially on M4. Although isolated teeth and partial jaw fragments of these species may be difficult to separate, more complete material as described here shows these forms to be distinct and the taxa valid. The most likely ancestor for P. pungens is the Riochican species Patene simpsoni. These taxa are similar in size and structure, but differ in P. pungens having P, set obliquely in jaw and being separated from C and P2 by distinct diastems, in lacking a metaconid, in a slightly more reduced talonid on MM, and in a more elongated and tricuspid M,. Perathereutes pungens is in turn similar to Borhyaenidium musteloides from beds of Huayquerian age and most probably represents an ancestor of that species. Both species have Px set at a slight oblique angle in the jaw, the Px is separated from the C and P2 by distinct diastems, and talonids (especially on M4) are more reduced than in species of Sipalocyon. Borhyaenidium musteloides differs from P. pungens primarily in being slightly larger in size and in the talonid basin being proportionately and absolutely more reduced. The fact that talonid reduction is already begun in P. pungens makes this species a more likely ancestor for B. musteloides than does S. gracilis. For S. gracilis to have been ancestral to B. musteloides, it would have had to have undergone talonid reduction and hence passed through a stage similar to that seen in P. pungens. The S. gracilis lineage, however, with the larger talonid basins appears to have continued into the Montehermosan as evidenced by Notocynus hermo- sicus. The lineages that terminated in the reduced talonid form of B. musteloides in the Huayquerian and the large talonid form of N. hermosicus in the Monte- hermosan were thus already distinct in the Santa crucian. Borhyaenidium Pascual & Bocchino, 1963 Borhyaenidium Pascual & Bocchino, 1963, p. 101. Type. — Borhyaenidium musteloides Pascual & Bocchino, 1963, p. 101. MARSHALL: REVIEW OF THE HATHLYACYNINAE 31 Distribution. — Known from beds of Huayquerian and Montehermosan age in Argentina. Diagnosis. — Similar in size to Sipalocyon and Notocynus; a large mental foramen occurs below posterior root of P,; P, separated from C and P2 by small diastems; talonid distinct, not basined, and relatively smaller than in Sipalocyon and No- tocynus; trigonid relatively narrower and more elongated than in Notocynus, Sipalocyon, and Perathereutes, and paraconid lies more directly anteriad of pro- toconid; protocone distinct but smaller than in Sipalocyon, Pseudonotictis, and Cladosictis, and set more anteriad relative to para- and metacone as in Chasicostylus castroi; paracone small and fused basally to larger metacone and becoming smaller from M1 to M\ whereas metacone becomes larger in same direction; para- and metacone set more labiad on M1 and more mediad on M3; parastyle large and elongated anteriorly on M1 and in same axis as para- and metacone; parastyle on M: shorter and set on anterolabial corner of tooth labiad to para- metacone axis; parastyle on M3 smaller and set completely on labial side of tooth; M3 with small but distinct ectoflex opposite metacone; metacrista well developed and its shear surface continues along inner surface of protocone. Borhyaenidium musteloides Pascual & Bocchino, 1963. Figures 22-25; Tables 5, 6. Borhyaenidium musteloides Pascual & Bocchino, 1963, p. 101, pis. 1, 2. Type. — MLP 57-X-10-153, poorly preserved partial skull with left M1'3 and right M2"3; a nearly complete left mandibular ramus with C, roots of P„ P23 complete, posterior half of M„ M; complete, and Mw missing tip of protoconid; a fragment of a right mandibular ramus with complete P3-M, and broken M:^; proximal and distal ends of a humerus; proximal end of an ulna; and assorted postcranial fragments, all of a single associated individual (figured by Pascual & Bocchino, 1963, pis. 1, 2). Hypodigm. — Type only. Horizon and locality. — Type from Epecuen Formation, Salinas Grandes de Hi- dalgo, La Pampa Province, Argentina. Age. — Huayquerian . Diagnosis. — Differs from Borhyaenidium riggsi in having, in most cases, slightly smaller linear tooth dimensions (see table 5); a slightly smaller talonid on M4; and a slightly smaller paracone (especially on M3). Comments. — It is probable that Perathereutes pungens is the Santacrucian ances- tor of Borhyaenidium musteloides. Perathereutes pungens is slightly smaller than B. musteloides, and its talonids are slightly larger and more distinctly basined. How- ever, these taxa are similar in having P, separated from C and P2 by small but distinct diastems. In Pseudonotictis pusillus the talonids are proportionately smaller relative to trigonids than occurs in species of Sipalocyon and Cladosictis. We thus see in P. pusillus the incipient talonid reduction that is continued in this lineage and that appears to a more extreme degree in B. musteloides. Borhyaenidium musteloides has a dental structure very similar to that of Chasi- costylus castroi. Both species have the upper molars greatly elongated antero- posteriorly, the parastyle on M1 is very large and projects anteriorly in the same axis as para- and metacone, whereas on M2 the parastyle is shorter and is set at the anterolabial corner of the tooth labiad to the para-metacone axis; protocone is reduced and is set anteriad of para- and metacone, and shear along metacrista 32 FIELDIANA: GEOLOGY Fig. 22. Borhyaenidium musteloides Pascual & Bocchino, 1963 (Huayquerian). MLP 57-X- 10-153 (type), a left maxillary with M1"3: a, labial; b, occlusal; c, lingual views. Scale = 10 is increased by elongation of that area and by its extension anteriorly along inner surface of protocone; lower molars are also elongated anteroposteriorly, espe- cially the protoconid and paraconid, and the talonid is more reduced than occurs in species of Sipalocyon, Cladosictis, and Notocynus. These features are thus very distinct, and they do not occur jointly in other borhyaenid species of similar size. Chasicostylus castroi differs from B. musteloides in being larger in size, in having a relatively larger protocone and talonid basin, and in having the protocone not set as far anteriad relative to the para- and metacones. Apart from these few differences, these taxa are structurally very similar. The dental specializations seen in C. castroi have been carried further in B. musteloides, in which the protocone is more reduced and is set more anteriad of the para- and metacone, resulting in elongation of the metacrista shear by making it more continuous and unobstructed. Borhyaenidium musteloides thus has slightly more advanced carnassial specializations than does C. castroi. z- o 9 i SB CM rl O ~ -r ^* «-l © o -r «* in r*S cS •*! P o 49 •t in in v© in vC On O * ao oo 00 f*i Tf ^1" ni cj »N . o o "♦ •** °) : no vO in in in ■* hx ^f in _ tn ro rj ni cj \o m in in v© in 33 I I I Fig. 23. Borhyaenidium musteloides Pascual & Bocchino, 1963 (Huayquerian). Stereopairs of MLP 57-X-10-153 (type), a left maxillary with M1"3: a, labial; b, occlusal; c, lingual views. Scale = 10 mm. Table 6. Measurements of mandibular rami of Borhyaenidium musteloides, B. riggsi sp. nov., and Notocynus hermosicus. Depth of Depth of ramus below ramus below labial side Breadth of labial side Breadth of Specimen of M, same of M4 sami Borhyaenidium musteloides MLP 57-X-10-153(l) MLP 57-X-10-153(r) 11.0 11.0 4.3 4.4 11.8 11.7 4.9 5.0 Borhyaenidium riggsi sp. nov. FMNH P14409(l) FMNH P14409(r) 11.0 10.9 4.2 3.8 10.2 9.9 5.4 5.2 Notoa/nus hermosicus MLP 11-91 10.7 4.2 34 £S 35 Fig. 25. Borhyaenidium musteloides Pascual & Bocchino, 1963 (Huayquerian). Stereopairs of MLP 57-X-10-153 (type), a nearly complete left mandibular ramus with C, roots of Pu P2.3 complete, posterior half of M,, M2 complete, and M3^ missing tip of protoconid: a, labial; b, occlusal; c, lingual views. Scale = 50 mm. 36 MARSHALL: REVIEW OF THE HATHLYACYNINAE 37 Borhyaenidium riggsi sp. nov. Figures 26-29; Tables 5, 6. Notocynus hermosicus Riggs & Patterson, 1939, p. 149. Etymology. — riggsi named in honor of Elmer S. Riggs, leader of the 1926-1927 Second Marshall Field Paleontological Expedition to Catamarca Province, Ar- gentina. Type. — FMNH P14409, two fragments of left maxillary, one with C and anterior root of P' and the other with M1'1; a left mandibular ramus with root of C, roots of P,.„ M, almost complete but missing anterior edge, M: missing talonid, and Mw complete; and a broken right mandibular ramus with roots of C-M4; all of a single, associated individual. c3o-l -fS(N • CM I-H .-l ,-H r-l NOvvOO t vo m m . ■* ■* \C \D MTl Ov t}< rj< in •<}< CM CM CM CM CM q q o q o r-« \0 >C «C \0 N >C in in in q i-h ts in in vd vd « S •I- o s & rx 3 vO [^ r^ 3C o ts OV 00 ON X, r^ r-v O <-H vd vO in in «' vC in t< ts t< iri in vd vd in ts CM in in m vO in in CM q CN CD K \0 vc sC ^c ^c ts vd K t< cn ^c sC vd vd O q in 00 ** oo q X Ov Tt in in vd ** ^ in 15 \6 -* >* in in o co in nO in TT vO in vO •£: co to oo ts ts is! nC sd ^c CN vd K N K sC 43 vd vd i tS. °°. m oo . ■«* in °°. 3C CM CM •<* co t*5 >* CO 1 Tf •* m rn ■* ■<* q -* co (N •* in m ^r en q ts vd d vO l< vO K N vd sC vd vd in ov in CM CM CM VOH^f in vd in i— i in in in vo CO CM CM CM CM T* T}< CM VO tS vd in in in in . . oo . . . . ts Ov 00 . 00 o . . 00 O O Ov • ,— i • I— 1 I— 1 T— 1 • t-H CM • •HMNH . . o . . . . 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PH <* x _ „ 90 rs r ^ X 9t 3~ ir, • in X x C x ir, ir, • >© ir, ir, x x ir, in ir, m m ID m ir. ir, T co cm in -f in -r C*J CO rj rt rj n rj r) CM rj CM fS cm ri ri rj ri n n 9 O 9 ir, m r^ B* 90 x ts cm ts C ir. in x ir. ir, ir, vO ir, ir, ir, ir, X tr, ir, ; m ^ ^ . in Tf «n ■ sO sO vO (SONh m vO t~s CN ifvi fl .R-.S ai 55 s* BWB)1 m ^rrl Fig. 41. Sipaloa/on gracilis Ameghino, 1887 (Santacrucian). Stereopairs of PU 15373, a nearly complete left mandibular ramus with most of dentition: a, labial; b, occlusal; c, lingual views. Scale = 50 mm. 56 MARSHALL: REVIEW OF THE HATHLYACYNINAE 57 AMNH 9238 (collected by B. Brown 1899); 10 miles south of Coy Inlet PU 15029 (collected by J. B. Hatcher 18%), 15148, 15154, 15312 (collected bv O. A. Peterson 18%); No data MLP 11-41, 11-76, 11-77, 11-105. Age. — Santacrucian. Diagnosis. — Slightly larger than Sipalocyon externa in linear tooth dimensions; differs from S. obusta in having a deeper and more robust mandibular ramus and a larger talonid on M . Description. — In the type of Sipalocyon gracilis, MACN 647, a very large mental foramen occurs below the P12 contact (its size is accentuated by the pathological disorder discussed below), and four smaller foramina occur more posteriorly — one below the middle of P2, one below P2.3 contact, one below the middle of Pj, and the largest of the four is below M,. The teeth are relatively unworn, indicating that this was a young animal. The PM are separated from each other by tiny diastems, and the alveolus of the anterior root of P, lies slightly labiad of the posterior alveolus. The P23 have small but distinct posterobasal cusps. A small but distinct entoconid and hypoconulid are easily distinguished on the talonid of M2, and together these cusps are about equal in size to the hypoconid. Periosteal proliferations. — Several specimens of S. gracilis (including MACN 647, 682, 683, 5%0, 6286) have a pathological disorder in the anterior part of the mandibular ramus. This infection is expressed as irregular rugosities around the mental foramina below the premolars and canine, often extending onto the symphyseal surface. In MACN 647, the type of S. gracilis, the bone in the symphyseal region and around the large mental foramen below the P,2 contact is swollen and is covered by numerous rugosities. The infection has resulted in a significant increase in size of this foramen. In MACN 682, the type of Amphithereutes amputans, a small rugosity occurs on the ventral border of the ramus below the P3-M, contact. In the type of Pera- thereutes obtusus, MACN 683, the symphyseal region and area below the pre- molars on the labial side is swollen and covered with rugosities. The anterior root of the P, is all but obliterated and is filled with secondary bone growth. This condition accentuated the size of the diastema between the C and P„ a feature noted by Ameghino in the original description of this species. In MACN 5960 the incisor region is greatly distorted by the infection and is an amorphous mass of secondary bone growth. The mental foramen below the P,.2 contact is extremely large and is surrounded and filled by rugosities. The ventral border of the ramus and the inner side of the symphysis are also affected, and rugosities extend to a point below the anterior root of the Pj. The C is very blunt, suggesting that infection caused malocclusion. The most extreme case of the infection occurs in MACN 6286. The entire canine alveolus and anterior root of the P, are filled with cancellous bone, and it appears that these teeth were either lost during the life of the animal or were never present. The ventral border of the symphysis is also very swollen, and the mental foramen below the P,.2 contact is enormous (4x2 mm), and the border is very swollen. Comments. — MACN 648 is listed as Sipalocyon gracilis in Ameghino's catalogue and on the specimen. There is, however, no direct reference to this specimen in Ameghino's description of this species, and it therefore does not appear to represent a syntype. MACN 648 is slightly larger than the type, MACN 647, and 58 FIELDIANA: GEOLOGY the posterobasal heel on the P3 is better developed. The Pj is separated from P2 by a small (1.5 mm) diastema. MACN 667 is listed as the "tipo" of Sipaloa/on mixtus in Ameghino's catalogue. However, he neither gave measurements for nor made special reference to this specimen in the original description of this species. The specimen used by Ameghino in the original description of S. mixtus is clearly MACN 5963, and this is the type. MACN 5963 is listed as S. mixtus in Ameghino's catalogue, but is not listed as the "tipo" either in the catalogue or on the specimen. The incisor alveoli of this specimen are broken away, and these teeth are not "rudimentary" as believed by Ameghino. In Ameghino's catalogue MACN 668 is listed as the "tipo" of Sipalocyon curtus. However, the specimen referred to in Ameghino's original description of this species is MACN 5960 (-62), which is identified by that name in his catalogue but is not listed as the type. Ameghino (e.g., 1894, fig. 52) figured, as Amphiproviverra manzaniana, a nearly complete palate with complete dentition. This figure is based on the left maxillary and premaxillary with complete dentition of the type of A. manzaniana, MACN 692. There is no trace of the right side nor did Ameghino note its presence in his catalogue. The only part of the upper right dentition preserved with the type is an isolated C. Ameghino apparently restored the right side in his figure by making a mirror image of the left. Fig. 42. Sipaloq/on gracilis Ameghino, 1887 (Santacrucian). PU 15373, left C-M4 of an incomplete skull: a, labial; b, occlusal; c, lingual views. Scale = 30 mm. MARSHALL: REVIEW OF THE HATHLYACYNINAE 59 I -r/ Fig. 43. Sipalocyon gracilis Ameghino, 1887 (Santacrucian). Stereopairs of PU 15373, left C-M4 of an incomplete skull: a, labial; b, occlusal; c, lingual views. Scale = 40 mm. Sipalocyon gracilis is, as noted above, very similar to the Colhuehuapian species S. externa and may be regarded as the direct descendant of that species. The primary changes in this lineage include a slight increase in size, shallowing of the ectoflex, and increase in size of the metacrista on M\ Sipalocyon gracilis is structurally very similar to the contemporaneous species Perathereutes pungens. Both have the P, set at a slight (10°) angle relative to the rest of the tooth row, P, is separated from C and P2 by small but distinct diastems, and talonids on MM are well developed and basined. These species differ in P. pungens being smaller in size, in having relatively larger talonids on MM, and in M, being relatively longer and narrower, and the paraconid being subequal to the talonid in size (latter is larger in S. gracilis). Overall, these differences are minimal, and Perathereutes and Sipalocyon appear to be more closely related than either is to any other contemporaneous genus. These genera shared a common ancestor (possibly in the Deseadan) that was not shared with any other known genus of Hathlyacyninae. 60 FIELDIANA: GEOLOGY Sipalocyon obusta (Ameghino, 1891c). Figures 44-^46; Table 14. Protoproviverra obusta Ameghino, 1891c, p. 313. Amphiproviverra obusta Ameghino, 1894, p. 389. Thylacodictis robusta (sic) Simpson, 1930, p. 51 Type. — MACN 686, a fragment of a left mandibular ramus with base of P3/ M,.2 complete, roots of M3/ M4 complete; and MACN 687, a fragment of a right mandibular ramus (both specimens are of same individual). Hypodigm. — Type only. Horizon and locality. — Collected by C. Ameghino in 1890-91 from the Santa Cruz Formation at Monte Observacion, Santa Cruz Province, Argentina. Age. — Santacrucian. Diagnosis. — Similar in size to S. gracilis, but with a very shallow and gracile mandibular ramus and a very reduced talonid on M4. Comments. — This species is tentatively recognized as valid. In size and struc- ture of the P3-M3 and trigonid portion of the M4, S. obusta is virtually identical to specimens of S. gracilis. However, it differs from specimens of S. gracilis in the M4 having a very reduced talonid and in the very shallow and gracile structure of the mandibular ramus. These features may be a reflection of the young age of this specimen because the posterior molars show no indication of occlusal wear and there are growth lines on the ramus in the area of the M4, suggesting that this element has not yet completed growth. This specimen might thus represent a variant individual of S. gracilis, although it is very unique and there Fig. 44. Sipalocyon obusta (Ameghino, 1891c) (Santacrucian). MACN 686 (type), a fragment of a left mandibular ramus with base of P3, Mw complete, roots of M3, and M4 complete: a, labial; b, occlusal; c, lingual views. Scale = 20 mm. Fie. 45. Sipalocyon obusta (Ameghino, 1891c) (Santacrucian). Stereopairs of MACN 686 (type), a fragment of a left mandibular ramus with base of Pj, M,.2 complete, roots of M3, and M, complete: a, labial; b, occlusal; c, lingual views. Scale = 30 mm. Fig. 46. Sipalocyon obusta (Ameghino, 1891c) (Santacrucian). MACN 686 (type), a fragment of a left mandibular ramus with base of P^ M,.2 complete, roots of Mj, and M, complete: top, occlusal; bottom, lingual views. Scale = 50 mm. 61 3 iriiri 3.2 2 2 * 2 <* «N II o 3 I a >** o 3 2 •rt £ *! '•& S °° M Q X in so so so SO t-s 00 00 sO sO 22 UU << 22 62 MARSHALL: REVIEW OF THE HATHLYACYNINAE 63 is nothing else quite like it in the Ameghino collection. Sipalocyon obusta thus apparently represents a species distinct from that of S. gracilis, and they may both have evolved from a Colhuehuapian ancestor like S. externa. Ameghino (1891c, p. 313) orginally placed this species in the Dasyura, family Thylacinidae, but later (1894, p. 389) put it in his group Sparassodonta, family Amphiproviverridae. Notocynus Mercerat, 1891b Notocynus Mercerat, 1891b, p. 81. Type. — Notocynus hermosicus Mercerat, 1891b, p. 81. Distribution. — Montehermosan, Buenos Aires Province, Argentina. Diagnosis. — As for type and only known species. Notocynus hermosicus Mercerat, 1891b. Figures 47, 48; Tables 5, 6. Notocynus hermosicus Mercerat, 1891b, p. 81; Ameghino, 1891f, p. 438; Rovereto, 1914, p. 159; Cabrera, 1927, p. 305, fig. 18; Ringuelet, 1966, p. 55, pi. 11, figs. D, E. Notocynus hermosieus (sic) Mercerat, 1898, p. 58. Didelphys triforata Ameghino, 1891f, p. 438 (partim). Type. — MLP 11-91, a fragment of a left mandibular ramus with roots of C and P,, base of P2, roots of P3-M: (M, crown was lost since the specimen was figured by Cabrera, 1927, fig. 18), M3 present but missing tips of protoconid and para- conid, and anterior root of M4 present. Hypodigm. — Type only. Horizon and locality. — Monte Hermoso, type locality of Montehermosan, Bue- nos Aires Province, Argentina. Age. — Montehermosan. Diagnosis. — Small borhyaenid, similar to Sipalocyon gracilis in size and structure; C weakly developed; tooth row tight, no diastems separating antemolar cheek teeth; PM aligned in same anteroposterior axis; P2 with small but distinct pos- terobasal heel; M,., with large-basined talonid; small anterobasal cingular cusp present on M:3, but not on M,; a large mental foramen opens below anterior root of P2, and another tiny one opens below posterior root of P2. Comments. — Notocynus hermosicus was erected by Mercerat (1891b, p. 81) on a partial left mandibular ramus collected from Monte Hermoso, type locality of the Montehermosan. Ameghino (1891f, p. 438) critically and unjustly attacked Mercerat, noting in his opinion that N. hermosicus was a synonym of Didelphys triforata. The latter, from the same locality as N. hermosicus, was earlier named and figured by Ameghino (1889, p. 280, pi. 22, figs. 37-38). Mercerat later (1898, p. 58) pointed out that Trouessart (1898, p. 1232) accepted N. hermosicus as valid, an opinion contra to that of Ameghino. Ameghino refused, however, to recognize this species, and in his classic work of 1898 Sinopsis geoldgico-paleontoldgica he did not even mention the name N. hermosicus. Cabrera (1927, p. 305, fig. 18) later redescribed and figured the type specimen (MLP 11-91) and rightly concluded that N. hermosicus was indeed valid. Two additional specimens from different horizons and localities than the type have been referred in literature to N. hermosicus. Riggs & Patterson (1939, p. 149) noted that: a portion of maxillary with M! and the mandibular rami of the small borhyaeninae may be referred with confidence to N. hermosicus Mercerat, hitherto known only from the Monte Hermoso beds. . . . 64 FIELDIANA: GEOLOGY Fig. 47. Notocynus hermosicus Mercerat, 1891b (Montehermosan). MLP 11-91 (type), a fragment of a left mandibular ramus with roots of C and Pl7 base of P2, roots of P3-M2, M3 present but missing tips of protoconid and paraconid, and anterior root of M4 present: a, labial; b, occlusal; c, lingual views. Scale = 20 mm. This specimen (FMNH P14409) from beds of Montehermosan age in the province of Catamarca is here (p. 37) named a new species of Borhyaenidium. Reig (1958a, p. 249) tentatively included cf. Notocynus hermosicus in a list of taxa from the Chapadmalal Formation. He later (1958b, p. 280) mentioned that this tentative identification was applied to a cranial fragment (MMP S-240) of a large marsupial that was distinct from other species in the fauna. He pointed out that this specimen was larger than Sparassocynus and did not have an epi- tympanic sinus, but there was evidence of a large alisphenoid bulla. Reig believed this specimen to be of a borhyaenid, and on the basis of its size had earlier (1958a, p. 249) assigned it provisionally to Notocynus. I have not seen this spec- imen, and its true identity is not known. Notocynus hermosicus is very similar to Sipalocyon gracilis (i.e., MACN 5938) from the Santacrucian. In both species there is a small but distinct heel on P2, the M3 has a very large and deeply basined talonid, there is a small anterobasal cingulum, and the size and proportions of the teeth and mandibular ramus are virtually identical. These species differ in N. hermosicus having the P! aligned in the same anteroposterior axis as the rest of the cheek teeth and not being set obliquely as in S. gracilis, and in the P, in N. hermosicus not being separated from MARSHALL: REVIEW OF THE HATHLYACYNINAE 65 Fig. 48. Notoa/nus hermosicus Mercerat, 1891b (Montehermosan). Stereopairs of MLP 11- 91 (type), a fragment of a left mandibular ramus with roots of C and P,, base of P2, roots of Pj-M2, Mj present but missing tips of protoconid and paraconid,and anterior root of M» present: a, labial; b, occlusal; c, lingual views. Scale ■ 30 mm. the C and P2 by diastems. These differences are minor, and I regard S. gracilis as the Santacrucian ancestor of N. hermosicus. Notogale Loomis, 1914 Notogale Loomis, 1914, p. 216. Type. — IPharsophorus mitis Ameghino, 1897, p. 504. Distribution. — Deseadan of Patagonia, and Bolivia. Diagnosis. — As for type and only known species. Notogale mitis (Ameghino, 1897). Figures 49-55; Table 15. IPharsophorus mitis Ameghino, 1897, p. 504. Notogale mitis Loomis, 1914, p. 216, figs. 142, 143; Patterson & Marshall, 1978, figs. 2-7. 66 FIELDIANA: GEOLOGY ■J" Fig. 49. Notogale mitis (Ameghino, 1897) (Deseadan). MACN 52-368 (type), a fragment of a right mandibular ramus with basal portions of M2.3: a, labial; b, occlusal; c, lingual views. Scale = 10 mm. Type. — MACN 52-368, a fragment of a mandibular ramus with basal portions of M2.3 (figured by Patterson & Marshall, 1978, fig. 2). Hypodigm. — The type and AC 3060, a fragment of a left mandibular ramus with P3 and M4 present (figured by Loomis, 1914, fig. 143; Patterson & Marshall, 1978, fig. 3); AC 3117, a left maxillary fragment originally with part of M2, M3 incomplete, and M4 (M4 now missing) (figured by Loomis, 1914, fig. 142; Pat- terson & Marshall, 1978, fig. 6); PU 21867, a fragment of a right mandibular ramus with talonid of M3, M4 complete (figured by Patterson & Marshall, 1978, fig. 4); PU 21868, a fragment of a right mandibular ramus with M3 (missing tip MARSHALL: REVIEW OF THE HATHLYACYNINAE 67 r Fig. 50. Notogale mitis (Ameghino, 1897) (Deseadan). Stereopairs of MACN 52-368 (type), a fragment of a right mandibular ramus with basal portions of \\_ . occlusal view. Scale = 20 mm. of protoconid) (figured by Patterson & Marshall, 1978, fig. 5c, d); PU 21869, a fragment of a right mandibular ramus with roots of C, Pi:, and anterior root of Pv PU 21871, a fragment of a rostrum with roots (or alveoli) of left IM, and base of right C, alveolus of left C, and roots of right P1; PU 21872, a fragment of a left mandibular ramus with P2 (figured by Patterson & Marshall, 1978, fig. 5a, b); PU 21874, a fragment of a left mandibular ramus with base of C and alveoli of I|.v PU 21875, a fragment of a right maxillary with M2 (figured by Patterson & Marshall, 1978, fig. 7, as an M1); PU 21876, a fragment of a left maxillary with M1; PU 21877, greater part of crown of C lacking enamel; PU 21993, a fragment of a right mandibular ramus with bases of M^ and PU 21996, a fragment of a right mandibular ramus with M2 (broken). Horizon and localities. — The type is probably, and the AC specimens are cer- tainly, from Cabeza Blanca, Chubut Province, Argentina. PU 219% is from Bra- nisa Loc. V-5, Salla-Luribay Basin; the other PU specimens are from the general locality of Salla, Bolivia. Age. — Deseadan. Diagnosis. — Similar in size and structure to species of Cladosictis from beds of Colhuehuapian and Santacrucian age of Argentina; upper and lower PI sepa- rated from C and P2 by small but distinct diastemas; PI -3 oriented along same axis as molar series, P) not set obliquely in jaw; P2 longer and narrower than P^ P3 with large, distinct posterobasal cuspule, a feature only faintly developed on Pz; protocone of M1 large, paracone about three-fourths size of metacone; para- cone and metacone approximated, united basally; parastyle small but distinct; stylar shelf virtually absent; protocone of M3 large; shallow ectoflex present; metastylar shear better developed than in M1; lower molars with small but distinct anterobasal cingulum; talonids of Mw distinct, narrower than trigonids; talonids of M3 with distinct hypoconid, entoconid, and hypoconulid; talonid of M< essentially unicusped with enlarged hypoconulid dominant; minute ento- conid and hypoconid visible in unworn teeth (e.g., PU 21867). Comments.— In the type (MACN 52-368) (figs. 49, 50), both teeth have lost all traces of enamel, their bases are fractured, and only a small portion of the mandibular ramus surrounding them is preserved. Their position in the series is not quite certain. Large alveoli can be seen anterior and posterior to them, and their size and relative proportions indicate that they are certainly molars. ■ cs o • ■<* in . t^ oo • tv rv ■> o CS| ~> : : a ^ "* : : : i C nO CO CO X a^ vC * NO • ■* vC •<* • in . o • NO m C-J co in . i— i a- rt X X X oo • oo On 3^ oo oo ■ 00 .oooininKM'j'N •\dininuSinininin Oi— i oo oo o\ csi ^ in OtJOOtNts'tsOONOO : 00 00 .MnnNOOfontN :inininiriinininin** 3 on o in no oo K .oooocsiTjirofNiroON ro ro . o : en . - * c •3 90 MARSHALL: REVIEW OF THE HATHLYACYNINAE 91 Fig. 67. Cladosictis patagonica Ameghino, 1887 (Santacrucian). Stereopairs of MACN 6280, a left maxillary fragment with C-M4 complete: a, labial; b, occlusal; c, lingual views. Scale for lingual view = 50 mm. Age. — Santacrucian. Diagnosis. — Slightly larger than Cladosictis centralis; talonid of M4 cuspate. Comments. — The type of Proviverra trouessartii (MACN 2079) consists of the greater part of a left side of a skull with partial dentition, but missing the basicranium, right zygomatic arch, right maxillary, and all of right dentition. This specimen is figured by Ameghino (1894, fig. 50; 1898, fig. 57c; 1904, fig. 24; 1906, fig. 190) in dorsal view in which the left side and posteriormost edge is restored. The canine and incisors were also restored because none are now present on the specimen. The zygomatic arch region is very narrow in the figure, reflecting the fact that the left arch, although almost complete, is crushed in this specimen but in life was certainly much broader. Ameghino restored the skull with the arches crushed, and the specimen and figure are identical in this respect. The palate and dentition of MACN 2079 are figured by Ameghino (1894, fig. 51; 1898, fig. 57d; 1906, fig. 189). Only parts of the left dentition are preserved, and these are precisely illustrated in the figures. Except for the roots of P' 2, all of the right dentition is missing. Ameghino restored the right side by making a mirror image of the left, a point which is readily apparent by comparing teeth on each side, which are broken in exactly the same way. . oo . • ■>* • • o • On • i-H in o o t* ro -^ rji • Os 00 CN CSI O • CO CO t}< tJ< rl< O O O ts 00 ts OOts iriNvooin ts ts t\ 00 K vO (N ^O ID ■* \£> co co co co co co ■* OS CO CO O ** O O O Os in! vri ts! ts! ts." vo O CN ts! ts! .(N OM3\H • co csi csj co . t— I CO CO ' CO CO CO ts. ts, vO 00 \o \d vd \d oo o o vo ts! is! t— i co co -^ in co CO co co co csi <* oo in ^ is! ts! ts! ts! ts! is in is is! . -* m ** • in CSI • CN CSI CN • CS| CO . in in m ,_ in • in in in •in ZZsOsONO>OvOvsON 22222Z2222ZZ2Z2hS UUUUUUUUUUUUUUUohCu 92 -J : -i On O : as ? u o : t< : ^ —j : ^ . o ■ oo : ^r in : ^i" : in : " : t^ : : t< : tvl K : K : *1 ^ fH • ^ : pS rn : (r> '• : H . rx rf . ON : vo vo : v£j • 'I ^ : pS rn . C»> Tt : t< r< • ^ : on On On : fvj (S ON in ■<* On o no k o © NO NO r-H Cn| t-H l-< en r •- 3 £ O U ra a 8 g o E o |"2 •2 m *- ~ 100 « I ■ « I I Fie. 73. Analherium herrerae sp. nov. (Colhuehuapian). Stereopairs of FMNH P13521 (type), greater part of a right mandibular ramus with base of C, and with P1-M4 (tips of Pj.2 and protoconid of M3 are missing): a, labial; b, occlusal; c, lingual views. Scale for labial view = 50 mm. 101 a 0 ~ >- oo 3 c CN Cn| in in On 00 T cL ro ro NO ON ^H tn t— i i— i in on no in i-i ^ Pu C 2222 2 XX 'f. U UU U 2 2 t < <<< c 22 PL, LL, T3 2S22 •S "< "< 102 MARSHALL. REVIEW OF THE HATHLYACYNINAE 103 Anatherium herrerae, sp. nov. Figures 72, 73; Tables 24, 25. Cladosictis sp. Sinclair, 1930, p. 39, pi. 8, fig. 4, 4a. Etymology. — herrerae named in honor of Senorita Hebe E. Herrera (Museo de La Plata, La Plata and Universidad de la Patagonia, Comodoro Rivadavia) in recognition of her ongoing studies of the marsupial fauna from, and geology of, the Barranca south of Lago Colhue-Huapi from whence this specimen was col- lected. Type. — FMNH P13521, associated left and right mandibular rami with bases of Cs, and P|-M« (tips of right P, ; and protoconids of right M3 and left Mw missing). Hypodigm. — Type only. Horizon and locality. — Colhue-Huapi Formation at Barranca south of Lago Col- hue-Huapi, Chubut Province, Argentina; collected by C. H. Riggs (son of E. S. Riggs) on Nov. 26, 1923. Age. — Colhuehuapian. Diagnosis. — Largest known species of genus; diastems separating P, from C and P: larger than in Anatherium defossus. Table 25. Measurements of mandibular rami of Anatherium defossus and A. herrerae sp. nov. Specimen Depth of ramus below labial side of M, Breadth of same Depth of ramus below labial side of M . Breadth of same A. defossus MACN9 MACN 5988 MACN 11-64 17.4 20.5 18.7 7.6 8.5 7.3 19.8 8.1 A. herrerae sp. nov. FMNH P13521(l) FMNH P13521(r) 21.0 21.5 9.3 10.0 22.4 10*8 Comments. — Anatherium herrerae is the largest species of Hathlyacyninae known. Apart from its slightly larger size and greater size of the diastems sep- arating P, from C and P2, A. herrerae is identical in dental morphology to the Santacrucian species A. defossus. I therefore recognize A. herrerae as the slightly larger Colhuehuapian ancestor of A. defossus. Anatherium defossus Ameghino, 1887. Figures 74-78; Tables 24, 25. Anatherium defossus Ameghino, 1887, p. 8; 1889, p. 289; 1891c, p. 315; 1891d, p. 354; 1894, p. 384; 1898, p. 192, fig. 57b; 1935, p. 110, fig. 10 (caption only). Anatherium defossus (sic) Palmer, 1904, p. 101. Hathliacynus defossus Mercerat, 1891a, p. 53. Acyon tricuspidatus Ameghino, 1887, p. 8; 1889, p. 290; 1894, p. 397; 1935, p. 110; Roger, 18%, p. 18. Acyon tricuspidactus (sic) Mercerat, 1891a, p. 55. Hathliacynus tricuspidatus Mercerat, 1891a, p. 52. Cladosictis tricuspidata Cabrera, 1927, p. 288, fig. 6. Acyon? bardus Ameghino, 1889, pp. 292, 293, pi. 1, fig. 18. Agustylus bardus Ameghino, 1894, p. 392; 1935, p. 109, fig. 9 (caption only). Ictioborus destructor Ameghino, 1894, p. 3%. 104 FIELDIANA: GEOLOGY Fig. 74. Anatherium defossus Ameghino, 1887 (Santacrucian). MACN 9 (type of Acyon? bardus), a fragment of a left mandibular ramus with roots of M^ M3 complete, M4 missing tip of protoconid (crowns of MM are heavily worn): a, labial; b, occlusal; c, lingual views. Scale = 20 mm. Type of Anatherium defossus. — MACN 669, a fragment of a right mandibular ramus with roots of I,.3, base of C, base of Pu and P2 complete (listed as "tipo" in Ameghino' s catalogue, and original description fits perfectly). Type of Acyon tricuspidatus. — MLP 11-64, a right mandibular ramus in two parts, anterior with root of C, alveoli of P12; and posterior with P3-M4 all present but partially broken (figured by Cabrera, 1927, fig. 6). Type of Acyon? bardus. — MACN 9, a fragment of a left mandibular ramus with roots of M,.2, M3 complete, M4 missing tip of protoconid — crowns of Mw are heavily worn (listed as "tipo" in Ameghino's catalogue and on specimen — fig- ured by Ameghino, 1889, pi. 1, fig. 18). Type of Ictioborus destructor. — MACN 5988, a fragment of a right mandibular ramus with posterior root of Pu roots of P23, M12 complete but very, very worn (this specimen is not listed as type in Ameghino's catalogue, but it is listed as "tipo" on a card with the specimen, and the original description of the species matches this specimen perfectly). Hypodigm. — The four types and MACN 646, a fragment of a left mandibular ramus with posterior half of P3, and roots of M12, base of M3 and anterior alveolus of M4 (listed as Agustylus bardus in Ameghino's catalogue). Fie. 75. Anatherium defossus Ameghino, 1887 (Santacrucian). Stereopairs of MACN 9 (type of Acyonl bardus Ameghino, 1889), a fragment of a left mandibular ramus with roots of M,.2, M3 complete, M4 missing tip of protoconid— crowns of Mj_, are heavily worn: a, labial; b, occlusal; c, lingual views. Scale = 30 mm. 105 106 FIELDIANA: GEOLOGY Fig. 76. Anatherium defossus Ameghino, 1887 (Santacrucian). MACN 9 (type of Acyonl bardus), a fragment of a left mandibular ramus with roots of M,.2, M3 complete, M4 missing tip of protoconid — crowns of MM are heavily worn: top, occlusal; bottom, lingual views. Scale = 30 mm. Horizon and locality. — All specimens are from the Santa Cruz Formation, Santa Cruz Province, Patagonia, Argentina. MLP 11-64 is probably from Monte Leon, MACN 9 is from Santa Cruz (date not specified but probably 1887), MACN 5988 is from Shehuen (1890-91), and MACN 646 and 669 are from Monte Observacion (1890-91); all were collected by C. Ameghino. Age. — Santacrucian . Diagnosis. — Largest known Santacrucian species of Hathlyacyninae; slightly smaller than herrerae; diastems separating P! from C and P2 smaller than in A. herrerae. Comments. — The type of Ictioborus destructor, MACN 5988, is the largest known specimen of Anatherium defossus. The ramus anterior to the posterior root of the Pi is missing, and this feature of preservation led Ameghino to believe that the P, was rudimentary and single rooted. Thus, he placed destructor in the genus Ictioborus, which he characterized as having a single-rooted, rudimentary Pj (see p. 94). MACN 5988 is a very old individual as evidenced by the deeply worn M,.2 in which the pulp cavities are exposed on Mj and nearly so on M2. This specimen has the most worn teeth of any animal in the Ameghino collection, and it may J Fig. 77. Anatherium defossus Ameghino, 1887 (Santacrucian). MACN 5988 (type of Ictio- borus destructor), a fragment of a right mandibular ramus with posterior root of Pu roots of P2.j, and M,.2 complete but very worn: top, occlusal; bottom, labial views. Scale = 50 mm. Fie. 78. Anatherium defossus Ameghino, 1887 (Santacrucian). Stereopairs of MACN 5988 (type of Ictioborus destructor), a fragment of a right mandibular ramus with posterior root of P,, roots of P2.v M|.2 complete but very worn: labial view. Scale = 50 mm. 107 108 FIELDIANA: GEOLOGY represent an aged male. Four mental foramina occur on the labial side of the ramus — a very large one below the P2 and three smaller ones of similar size below the anterior roots of P2, M„ and M2, respectively. This animal has the same pathological disorder as occurs in specimens of Sipalocyon gracilis (see p. 57), as evidenced by the irregular rugosities around the second and third most anterior mental foramina and along the inner surface of the symphysis. Acyonl tricuspidatus was diagnosed by Ameghino (1887, p. 8) as having four tricuspate lower premolars. This, however, is not so — the P3 crown on the type (MLP 11-64) was erroneously restored onto the broken base of the M„ giving the impression that there were four premolars in this specimen. I have restored the P3 into its proper position, and the species tricuspidatus now shows no differences with respect to other specimens here assigned to A. defossus. Hathlyacyninae Indeterminate Simpson (1948, pp. 48-49) recorded the presence of a number of fragmentary specimens and isolated teeth from beds of early Tertiary age in Patagonia. These could not be assigned to named taxa and themselves were inadequate to be made types of new species. Many, if not all, appear to represent generalized borhyaenids, and they may prove referable to the Hathlyacyninae. However, I can add little to Simpson's comments about these specimens, and they must remain in taxonomic limbo. The same is true for the unnamed specimens men- tioned by Paula Couto (1970) from the Riochican fissure fills at Sao Jose de Itaborai, Brazil. Palaeocladosictis mosesi Paula Couto (1961, p. 332, fig. 12) from Itaborai was based on what was called an upper M1 or M2 (MNRJ 2671-V). In the original description it was compared with Cladosictis and Thylacodictis ( = Sipalocyori) and was thus associated with members of the Hathlyacyninae. This tooth is, how- ever, not of a borhyaenid, but represents a DP4 or P4 of some sort of ungulate (Marshall, 1978, p. 70). Summary of Evolution of Hathlyacyninae Members of the borhyaenid subfamily Hathlyacyninae are known from beds of Riochican (late Paleocene) through Montehermosan (early Pliocene) age in Argentina and beds of Deseadan (early Oligocene) age in Bolivia. Eighteen species and 12 genera are recognized: Patene simpsoni, P. coluapiensis, Procladosictis anomala, Pseudonotictis pusillus, Notictis ortizi, Perathereutes pungens, Borhyaenidium musteloides, B. riggsi, Sipalocyon externa, S. gracilis, S. obusta, Notocynus hermosicus, Notogale mitis, Cladosictis centralis, C. patagonica, Chasicostylus castroi, Anatherium herrerae, and A. defossus. Upper dentitions of various species showing relative proportions and size of the teeth are compared in Figure 79, and lower dentitions are compared in Figure 80. A summary of various characters, some diagnostic, for the genera are pre- sented in Table 26. Size distributions as indicated by length of Mw and length versus width of M4 are compared in Figures 81 and 82, respectively. These plots demonstrate that absolute and/or relative size differences are sufficient in most cases to differentiate species of a given age. Based largely on basicranial characters, the Hathlyacyninae have been shown (Marshall, 1978, p. 72, fig. 13) to be a monophyletic group relative to other MARSHALL: REVIEW OF THE HATHLYACYNINAE 109 borhyaenid subfamilies. Dentally, hathlyacynines are the most generalized of known borhyaenids and share a number of features with their presumed di- delphoid ancestors. Included, among other features, are a high incisor number; their generally small to medium size; their long, shallow, and generally gracile mandibular rami; symphysis ligamentous and rami unfused in adults; C weakly or moderately developed; presence of a metaconid in earliest forms (i.e., Patene); M,.j typically with large-basined talonids; and a large protocone and wide stylar shelf on M1'3 in early forms. The general evolutionary trend among hathlyacynines has been the increase in carnassial specializations resulting in loss of metaconid and reduction in size of protocone, stylar shelf, and talonid. A general trend of size increase also occurs, although some recognized lineages show size reduction and others show no significant size change. The general conclusion that can be made regarding the evolution of this group is that it has been extremely conservative with regard to the other borhyaenid subfamilies. Further, if sheer numbers of individuals and taxa are a gauge, then it has also been the most successful. The recognized species of Hathlyacyninae are listed in Figure 83 in order of their chronostratigraphic occurrence and with an indication of their probable phylogenetic relationship. The proposed phylogeny is based largely on the data set in Table 26, although it includes consideration of other features discussed in the text. The character states that occur in Patene are regarded as plesiomorphic for the subfamily. Patene simpsoni is the most generalized of known borhyaenids, and if more ABC ^v^^ ^M£%% t^zs^w *&& px^ c? £? Fig. 79. Comparison of upper dentitions of various species of Hathlyacyninae showing relative size and proportions of teeth. All illustrations are drawn to same scale. A, labial; B, occlusal; C, lingual views. 1, Cladosictis patagonica; 2, Chasicostylus castroi; 3, Notogale mitis; 4, Sipalocyon gracilis; 5, Sipalocyon externa; 6, Borhyaenidium riggsi; 7, Borhyaenidium musteloides; 8, Pseudonotictis pusillus; 9, Procladosictis anomala; 10, Patene coluapiensis; 11, Patene simpsoni. 110 FIELDIANA: GEOLOGY ^ £v3 d^ z> <^\_Jcs2 Q, (SSOQccss^ c^L^cU^ i^SxJ^ ^CO^fecs A_^£^ ^^b^^ C5£53£3£eo«3 ^^^^^ ^^^^i^ (g^B^S^S^ ^S^d^A^ -^-j^^ Cc^S^j^ccX)0 *=* Aftm^-- ^%^^^ OQssssds^csj o° £km£^ Q^CS^L G^£l£C2£S£>p ooo oo *^_j£iv353o53o £*&&& •«eDC3cr>DC»o • ££*23£i ><^££&£> ^^^gj^S^JCS) s> <&&&S&J^ !d& CBCD j .5 i -V 2 i -a 2 - f £ .5 f E S. li i Is 1 II I * 1 1 6 22 II 2 3 v I* I V ! 22 i 6 _ ^ HI f ir~i = c " s §i =5 8. I 1 -c2 f 2 2 .5 . £ f | | .11 ll| .1 i. c pa li! - «r « if XI 2 '3 ^a*| rnilr III 1 . £ 1 li II -off 1153 h Li22 J ,,1 .-1 M £1 J 1 js-S \ 111 CO O CO CM 00 CM - c J ^3- 1^ CM CO CM CM CM CO CM CM CM o>_ 00_ r^_ •I T3 ^3 O «, * SX 3 • in >> CO •— CO CO •-~ .w TO .CO co TO CO CD > ^ ^ .N c CD CO O) ;6 c TO CO -c o OQ to -Q O c o O o TO Q. CO •^ .O 3 TO . . . t/i .2 -H- 3 c 1 5 i— i >^ 00 * (j « a | CO Q. .CO O o c d> CO o. c o .CO o o 0> c Q. CO to "5 Q) v. TO v. a> CL 5 5 c TO CO i«s o o CO k. D) c o o o to Q. CO 1 TO TO O) O O =2 TO k. C CD O .CO O CO O ■o TO O C o O) TO TO Q. .co O CO O ■o TO O co CO O •*— TO ■o E "C CD TO C CD -C °c CD TO C CQ •~" 112 MARSHALL: REVIEW OF THE HATHLYACYNINAE 113 The Casamayoran species Patene coluapiensis differs from P. simpsoni in being about one-fourth to one-third larger in linear tooth dimensions, in having rel- atively smaller protocones and a slightly narrower stylar shelf on M1 \ a more reduced metacone on M\ and a slightly deeper ectoflex on M\ These taxa are very similar in other respects, and considering their occurrence in successive- aged beds, I recognize P. coluapiensis as the slightly larger and more specialized Casamayoran descendant of P. simpsoni. Procladosictis anomala from beds of Mustersan age has a relatively smaller and cuspate protocone than in species of Patene, and the M3 has a very deep ectoflex. The latter feature is not found in any other borhyaenid and excludes P. anomala as a potential ancestral form for any known later taxa. Procladosictis anomala is here regarded as a slightly larger, specialized, dead-end descendant of the Casa- mayoran species Patene coluapiensis. A metaconid is definitely known only in Patene simpsoni and by inference in P. coluapiensis as well. An isolated lower molar possibly referable to the Mustersan genus Procladosictis also has a metaconid (see p. 18), whereas all known post- Mustersan hathlyacynines lack a metaconid. Loss of this structure thus occurred early in the evolutionary history of this group, although the exact time of loss cannot yet be firmly established. It is, however, assumed in the phylogeny proposed in Figure 83 that metaconid loss occurred independently at least two times within the Hathlyacyninae. Pseudonotictis pusillus is the smallest species of borhyaenid known, being slightly smaller in most comparable linear tooth dimensions than the Riochican species Patene simpsoni (compare measurements in tables 1 and 2). Pseudonotictis pusillus differs from Patene simpsoni in having more advanced carnassial special- izations (i.e., more reduced protocone, stylar shelf, and talonid; loss of meta- conid; elongation of M,; and increase in size and importance of postvallum- prevallid shear). These changes are nevertheless minor considering the time separating these species, and I choose to regard Patene simpsoni as the probable structural ancestor of P. pusillus. Notictis ortizi is the smallest species of post-Santacrucian borhyaenid known and is very similar to Pseudonotictis pusillus. Both species are of similar size with virtually identical molar structure, with weakly developed canines, and with mental foramina of similar size, shape, and position. In N. ortizi, the premolars are absolutely and relatively smaller than in P. pusillus, and the premolar region is foreshortened, the premolars crowded, and the P, is set obliquely in the jaw. The differences in N. ortizi represent but slight specializations of features seen in P. pusillus, and an ancestral-descendant relationship for these species seems probable. Perathereutes pungens from the Santacrucian is intermediate in size between the contemporaneous smaller Pseudonotictis pusillus and the larger Sipalocyon gracilis. I propose that Perathereutes pungens shared a common ancestry with Pseudonotictis pusillus and that this ancestor was characterized by somewhat reduced talonid basins, lack of a metaconid, and presence of small but distinct diastems between C, P„ and P2. Perathereutes pungens is, in turn, here regarded as the most likely known ances- tor for the Huayquerian species Borhyaenidium musteloides. Both species have P, set at a slight oblique angle in the jaw and separated from the C and P2 by diastems, and the talonids (especially on M«) are comparably more reduced relative to other similar-sized Hathlyacyninae. Borhyaenidium musteloides differs §..» F O ^: 3 O O TO 2 o ... Q. O) c oo U) in / , s £ •n VI u x 7J C c Id « 3 C 3 •3 3 SL en — * 01 §"? « H £S *« C o « •y j- c re §05 o -^ fl MN 3 0 cr 9 C w .9 c S'S. in £ 01 J5 .a o tn (j . 60 o c '5 114 MARSHALL: REVIEW OF THE HATHLYACYNINAE 115 South American Land Mammal Aga Montana rmoaan Borhyaemdium nggs, Notocynus harmosicus Huayqoanan Notictia ortizi Borhyaemdium musleloides Chaaicoan Fnaaian Chastcostytus castroi Santacrucian Pseudonotictis Perathereutes Sipalocyon Sipalocyon pusillus pungens obusta gracilis CtadOSiCtiS Anathenum patagonica delossus Cladosictis Anatherium centralis herrerae Fig. 83. Dendrogram showing probable phylogenetic relationships of the genera and species of Hathlyacyninae. from P. pungens in being slightly larger in size and in the talonid basin being proportionately and absolutely more reduced. The Montehermosan species Borhyaenidium riggsi differs from B. musteloides in having, in most cases, slightly larger linear tooth dimensions, a slightly larger M« talonid, and a slightly larger paracone. In other respects these species are inseparable, and they are regarded as representing a single evolutionary lineage. It is proposed that Perathereutes and Sipalocyon shared a common ancestor characterized by a P, set at a slight angle relative to the rest of the tooth row, small diastems separating C, P„ and P2, and talonids on MM being well devel- oped and basined. The Colhuehuapian species Sipalocyon externa is slightly smaller and more gracile than the Santacrucian species S. gracilis, but morphologically these species are virtually indistinguishable. Consequently, I recognize S. externa as the prob- 116 FIELDIANA: GEOLOGY able Colhuehuapian ancestor of S. gracilis. The primary changes in this lineage include slight increase in size, shallowing of the ectoflex, and increase in size of metacrista on M3. Sipalocyon gracilis is the most abundant borhyaenid in the Santa Cruz fauna of Patagonia, southern Argentina. A contemporaneous species, S. obusta, is known only from its type and differs from the large comparative sample of S. gracilis in having a very shallow and gracile mandibular ramus and a very reduced talonid on M4. In other respects S. obusta is indistinguishable from S. gracilis. Sipalocyon obusta is tentatively recognized as a valid species, although it may represent a variant individual of S. gracilis. Both S. gracilis and S. obusta can be easily derived from the Colhuehuapian species S. externa. The Montehermosan species Notocynus hermosicus is very similar to Sipalocyon gracilis; both species are of comparable size, they have a small but distinct heel on P2, M3 has a very large and deeply basined talonid and a small anterobasal cingulum, and the size and proportions of the teeth and mandibular rami are virtually identical. These species differ in N. hermosicus having P, aligned in the same anteroposterior axis as the rest of the tooth row and not being set obliquely as in S. gracilis and in the Pj in N. hermosicus not being separated from the C and P2 by diastems. These differences are minor, and I regard S. gracilis as the probable Santa crucian ancestor of N. hermosicus. The remaining Hathlyacyninae are recognized as monophyletic and can ul- timately be derived from the Casamayoran species Patene coluapiensis. These taxa of the genera Notogale, Cladosictis, Chasicostylus, and Anatherium are of medium to large size, P2 ~ P3, metaconid is absent, talonid of M4 is very small with a shallow basin or cuspate, stylar shelf is very reduced or absent, and talon on M1"4 is moderately developed with a shallow basin or cuspate. The Deseadan species Notogale mitis is a similar size to Patene coluapiensis and can be derived from the latter with a slight reduction in size of the protocone and stylar shelf. Cladosictis and Anatherium shared a post-Deseadan common ancestor that was of large size, had C, Pv and P2 separated by large diastems, and had more reduced protocones and talonid basins than N. mitis. Cladosictis centralis from the Colhuehuapian is known only by a few specimens. These specimens are smaller than the large comparative sample of the Santa- crucian C. patagonica. In other respects these species are inseparable, and I recognize C. centralis as the slightly smaller Colhuehuapian ancestor of C. pa- tagonica. The Chasicoan species Chasicostylus castroi is here regarded as a direct de- scendant of the Santacrucian species Cladosictis patagonica. These species differ in C. castroi being slightly larger in size, in having the upper and lower molars proportionately more elongated anteroposteriorly, in the upper molars having a larger parastyle that extends more anteriorly, in having the protocone set more anteriad relative to the para- and metacone, and in having a more elongated metacrista. These differences show C. castroi to have better developed shearing specializations than occur in Cladosictis patagonica. The species of Anatherium are the largest members of Hathlyacyninae known, and the talonids of M,^ are more reduced than in species of Cladosictis. The Colhuehuapian species A. herrerae is the largest member of the genus, and the diastems separating P, from C and P2 are larger than in the Santacrucian species A. defossus. Both A. herrerae and A. defossus are poorly known, and their specific separation will require reconsideration pending discovery of larger sample sizes. MARSHALL: REVIEW OF THE HATHLYACYNINAE 117 For the present, A. herrerae is regarded as the slightly larger Colhuehuapian ancestor of A. defossus. LITERATURE CITED Amechino, F. 1887. Enumeration sistematica de las espeties de mamiferos fosiles colec- cionados por Carlos Ameghino en los terrenos eocenos de la Patagonia austral y de- positados en el Museo La Plata. Bol. Mus. de La Plata, 1: 1-26. . 1889. Contribuci6n al conocimiento de los mamiferos fdsiles de la Republica Ar- gentina, obra escrita bajo los auspicios de la Academia National de Cientias de la Republica Argentina para presentarla a la Exposition Universal de Paris de 1889. Actas Acad. Cienc. Cbrdoba, VI, xxxiii+ 1,027 pp; atlas, 98 pis. -. 1891a. Caracteres diagnostics de tincuenta espeties nuevas de mamiferos f6siles argentinos. Rev. Arg. Hist. Nat., 1: 129-167. 1891b. Adiriones al eximen de los mamiferos f6siles, tratados en al articulo IV anterior por German Burmeister. Rev. Arg. Hist. Nat., 1: 259-270. -. 1891c. Nuevos restos de mamiferos fbsiles descubiertos por Carlos Ameghino en el Eoceno inferior de la Patagonia austral. Espeties nuevas, aditiones y correctiones. Rev. Arg. Hist. Nat., 1: 289-328. 1891d. Observariones criticas sobre los mamiferos eocenos de la Patagonia austral. Rev. Arg. Hist. Nat., 1: 328-380. -. 1891e. Los monos f6siles del Eoceno de la Republica Argentina. Rev. Arg. Hist. Nat., 1: 383-397. . 1891f. Sobre la supuesta presentia de creodontes en el Mioceno superior de Monte- Hermoso. Rev. Arg. Hist. Nat., 1: 437-438. 1894. Enumeration synoptique des espeties de mammiferes fossiles des formations eocenes de Patagonie. Bol. Acad. Cienc. C6rdoba, 13: 259-452. 1897. Mammiferes Cretaces de 1' Argentine. (Deuxieme contribution a la connais- sance de la faune mammalogique des couches a Pyrotherium.) Bol. Inst. Geog. Argentine 18: 406-521. 1898. Sinopsis geol6gico-paleontologica. Segundo censo de la Republica Argentina. Fol., Buenos Aires, 1: 112-255. 1902a. L'age des formations sedimentaires de Patagonie. An. Soc. Cien. Argentina; L: 109-130; 145-165; 209-229 (1900). LI: 20-39; 65-91 (1900). LII: 189-197; 244-250 (1901). LIV: pp. 161-180; 220-249; 283-342 (1902). 1902b. Notice preliminaires sur les mammiferes nouveaux des terrains cretaces de Patagonie. Bol. Acad. Cienc. C6rdoba, 17: 5-70 (1902-04). -. 1902c. Premiere contribution a la connaissance de la fauna mammalogique des couches a Colpodon. Bol. Acad. Cienc. C6rdoba, 17: 71-141 (1902-04). 1904. Paleontologia argentina. Publicariones de la Universidad de La Plata. Fa- culdad de cientias h'sico-matimaticas, no. 2: 1-79. . 1905. La faceta articular inferior unica del astragalo de algunos mamiferos, no es un caracter primitivo. An. Mus. Nac. Buenos Aires, (3)5: 1-64. . 1906. Les formations sedimentaires du cretace superieur et du Tertiare de Patagonie avec un parallele entre leurs faunes mammalogiques et celles de L'antien continent. An. Mus. Nac. Buenos Aires, (3)8; 1-568. -. 1935. Los Esparasodontes ... A. J. Torcelli (ed.), Ameghino Obras, 19: 103-140 (published posthumously). Burmeister, G. 1891. Aditiones al examen critico de los mamiferos fosiles tratados en el articulo IV anterior. An. Mus. Nac. Buenos Aires, 3: 375-400. Cabrera, A. 1927. Datos para el conocimiento de los dasyuriodeos f6siles argentinos. Revta. Mus. La Plata, 30: 271-315. Hoffstetter, R. 1968. Un gisement de mammiferes Deseadiens (Oligocene inferieur) en Bolivie. C R. Acad. Sti. Paris, 2670: 1095-1097. . 1976. Rongeurs caviomorphes de 1'Oligocene de Bolivie. I. Introduction du De- seadien de Bolivie. 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