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Early Tertiary Tapiroidea of Asia. Bulletin of the AMNH ; v. 129, article 2

Show simple item record Radinsky, Leonard B. en_US Central Asiatic Expeditions (1921-1930) en_US 2005-10-06T15:54:34Z 2005-10-06T15:54:34Z 1965 en_US
dc.description p. 183-263 : ill., map. ; 27 cm. en_US
dc.description Includes bibliographical references (p. 262-263). en_US
dc.description.abstract "Early Eocene tapiroids in Asia are known only from a single specimen, representing a form similar to the North American isectolophid Homogalax. The middle Eocene record is equally poor. One isolated lower molar of a form possibly ancestral to the late Eocene genus Teleophus is the only Asiatic tapiroid fossil of undoubted middle Eocene age. In beds that may be late middle or early late Eocene in age, Veragromovia, a genus based on a single upper molar, represents a form similar to the North American helaletid Helaletes, and Schlosseria, a better-known genus with a tridactyl manus, provides an approximate ancestor for the late Eocene genus Lophialetes. Several relatively rich late Eocene faunas reveal a great variety of tapiroids in Asia at that time. Whether this indicates an evolutionary radiation of tapiroids in the late Eocene or merely reflects uneven knowledge of the fossil record is a moot point. Early late Eocene (Irdin Manha age) tapiroids represent at least three families, the Helaletidae, known also in North America, and two newly recognized, solely Asiatic families, the Lophialetidae and the Deperetellidae. The helaletids include advanced species of Helaletes (formerly assigned to Desmatotherium) and a form similar to the North American genus Hyrachyus. The lophialetids are represented by the very abundant Lophialetes, a genus with rhinocerotoid-like molars, and a new genus, Breviodon, a small tapiroid with P[subscript]1-2 lost. A small form with P[superscript]1 lost and convex molar metacones may be related to Breviodon or may represent a distinct new genus. Two new genera, Rhodopagus and Pataecus, both diminutive forms, appear to be divergent offshoots from the Lophialetidae, in which the long molar ectolophs were lingually displaced and run parallel to or confluent with the metalophs. Early late Eocene deperetellids are represented by Teleolophus, a genus with bilophodont molars. In late late Eocene (Shara Murun age) Asiatic faunas, tapiroids are less abundant in both numbers and diversity. Helaletids are represented by species of Colodon, a genus also known in North America. Lophialetids, the dominant elements in early late Eocene faunas, are no longer present. Deperetellids are represented by Deperetella (including Cristidentinus and Diplolophodon), a descendant of Teleolophus in which the anterior premolars are disproportionately lengthened, in specialization for vertical shear. Indolophus, a poorly known Burmese genus, appears to represent an otherwise unknown tapiroid lineage and cannot be assigned to any existing family. Tapiroids are extremely rare in Oligocene deposits in Asia and are represented by only one genus, Colodon (including Paracolodon). Postcranial remains are known for Schlosseria, Lophialetes, and Deperetella. In all three genera the fifth metacarpal is reduced to a tiny vestige and the remaining metacarpals are relatively long and thin, indicating specialization for running. In Deperetella, elongate cervical vertebrae and a high radio-humeral ratio suggest a fleet, gazelle-like animal. It is suggested that the relatively great diversity of late Eocene tapiroids in Asia may be related to the scarcity of artiodactyls in the same faunas. The geographic distribution of late Eocene tapiroids in Asia provides no evidence for climatic zonation at that time. The occurrence of helaletid and isectolophid tapiroids in Asia supports other evidence for faunal exchange between Asia and North America during early and late Eocene time"--P. 261. en_US
dc.format.extent 52523269 bytes
dc.format.mimetype application/pdf
dc.language eng en_US
dc.language.iso en_US
dc.publisher New York : [American Museum of Natural History] en_US
dc.relation.ispartofseries Bulletin of the American Museum of Natural History ; v. 129, article 2 en_US
dc.subject.lcsh Perissodactyla, Fossil -- Asia. en_US
dc.subject.lcsh Perissodactyla, Fossil -- Mongolia. en_US
dc.subject.lcsh Perissodactyla, Fossil -- China -- Inner Mongolia. en_US
dc.subject.lcsh Mammals, Fossil -- Asia. en_US
dc.subject.lcsh Mammals, Fossil -- Mongolia. en_US
dc.subject.lcsh Mammals, Fossil -- China -- Inner Mongolia. en_US
dc.subject.lcsh Paleontology -- Paleogene -- Asia. en_US
dc.subject.lcsh Paleontology -- Paleogene -- Mongolia. en_US
dc.subject.lcsh Paleontology -- Paleogene -- China -- Inner Mongolia. en_US
dc.subject.lcsh Paleontology -- Asia. en_US
dc.subject.lcsh Paleontology -- Mongolia. en_US
dc.subject.lcsh Paleontology -- China -- Inner Mongolia. en_US
dc.subject.lcsh Tapiridae -- Evolution. en_US
dc.title Early Tertiary Tapiroidea of Asia. Bulletin of the AMNH ; v. 129, article 2 en_US
dc.type text en_US

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  • Bulletin of the American Museum of Natural History
    The Bulletin, published continuously since 1881, consists of longer monographic volumes in the field of natural sciences relating to zoology, paleontology, and geology. Current numbers are published at irregular intervals. The Bulletin was originally a place to publish short papers, while longer works appeared in the Memoirs. However, in the 1920s, the Memoirs ceased and the Bulletin series began publishing longer papers. A new series, the Novitates , published short papers describing new forms.

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