57 research outputs found
Craniodental materials of Litolophus gobiensis.
26, [1] p. : ill. ; 26 cm.
"June 25, 2010."
Includes bibliographical references (p. 19-22).We describe new craniodental specimens of Litolophus gobiensis recently unearthed from the type locality of the genus, and conduct phylogenetic analyses of Eocene chalicotheres based on a data matrix containing 21 taxa and 58 craniodental characters. Although the phylogenetic relationships of the Eocene chalicotheres are not well resolved in the strict component consensus tree, the 50% majority rule consensus shows that two post-earliest Eocene chalicothere lineages are present. The first lineage represents the main line of chalicothere evolution, including "Grangeria" anarsius, Eomoropus, and post-Eocene chalicotheres. The second lineage, consisting of Litolophus gobiensis and Grangeria canina, is the sister group and stem member to the main lineage. The derivative strict reduced consensus tree, with three unstable taxa pruned, supports some tree topologies of the 50% majority consensus. The taxonomy of some chalicothere taxa is revised based on the phylogenetic analyses, such as "Grangeria" anarsius being probably better referred to the genus Eomoropus as originally identified, E. ulterior being the sister taxon to E. amarorum, and Lophiodon being excluded from the Ancylopoda but allied with the Ceratomorpha
Biostratigraphy and diversity of Paleogene perissodactyls from the Erlian Basin of Inner Mongolia, China.
60 pages : illustrations (some color), maps ; 26 cm.Extant perissodactyls (horses, rhinos, and tapirs) comprise a small portion of living mammals, but fossil perissodactyls were more diverse and commonly dominated Paleogene faunas. Unfortunately, the taxonomy and distribution of some Chinese Paleogene perissodactyls remain controversial and unclear, hampering the correlation of Asian paleofaunas with paleofaunas from other continents. Here we clarify the temporal and spatial distribution of Paleogene perissodactyl species from the Erlian Basin based on published specimens, archives, and our recent fieldwork. The strata of the Erlian Basin range nearly continuously from the late Paleocene to the early Oligocene, and almost all Eocene Asian Land Mammal Ages (ALMA) are based on corresponding faunas from the Erlian Basin. We revise the most complete section of deposits at Erden Obo (=Urtyn Obo) that range in age from the late Paleocene to the early Oligocene in the Erlian Basin, and correlate it with other type formations/faunas in the basin based mainly on the perissodactyl biostratigraphy and lithostratigraphy. Furthermore, we discuss perissodactyl faunal components and their diversity from the early Eocene to the early Oligocene in the Erlian Basin, as well as the correlation between middle Eocene ALMAs and North American Land Mammal Ages based on perissodactyl fossils. The general decrease in perissodactyl diversity from the middle Eocene to the late Eocene can probably be attributed to a global climatic cooling trend and related environmental changes. The diversity of perissodactyls declined distinctly during the Eocene-Oligocene Transition, when global average temperatures dropped considerably
New material of alagomyids
29 p. : ill. ; 26 cm.Includes bibliographical references (p. 26-29).Newly discovered specimens of alagomyids, mostly isolated teeth collected by screenwashing at the Gashatan (late Paleocene) Subeng locality in Inner Mongolia, document considerable intraspecific variation in Tribosphenomys minutus that has not been appreciated previously because of limited sample sizes. P4s of Tribosphenomys are described for the first time, which helps to clarify the posterior premolar identification of alagomyids. Some of the alagomyid specimens are referred to Tribosphenomys cf. T. secundus and Neimengomys qii gen. and sp. nov. Based on the new data, Tribosphenomys borealis from the Bumban Member of the Naran Bulak Formation, Mongolia, is considered to be a junior synonym of Alagomys inopinatus, and T. tertius from the Zhigden Member of the Naran Bulak Formation is regarded as a junior synonymof T. minutus. Alagomyidae, consisting of Tribosphenomys, Alagomys and Neimengomys, is maintained as a valid family. The presence of a diversity of alagomyids and other recently obtained fossils and stratigraphic evidence from the Erlian Basin suggest that the Gashatan and Bumbanian of Asia are probably correlative to the late Tiffanian-early Wasachian of North America. The faunal turnover during the Gashatan and Bumbanian in Asia is probably related to the late Paleocene-early Eocene global warming, but current evidence is insufficient to link any specific event with the Paleocene-Eocene Thermal Maximum
New ctenodactyloid rodents from the Erlian Basin, Nei Mongol, China, and the phylogenetic relationships of Eocene Asian ctenodactyloids /
no. 382
New ctenodactyloid rodents from the Erlian Basin, Nei Mongol, China, and the phylogenetic relationships of Eocene Asian ctenodactyloids /
A new species of Chungchienia (Tillodontia, Mammalia) from the Eocene of Lushi, China. American Museum novitates ; no. 3171
10 p. : ill. ; 26 cm.Includes bibliographical references (p. 9-10
A new species of Chungchienia (Tillodontia, Mammalia) from the Eocene of Lushi, China. American Museum novitates ; no. 3171
A new species of Chungchienia (Tillodontia, Mammalia) from the Eocene of Lushi, China. American Museum novitates ; no. 3171
New stratigraphic data from the Erlian Basin : implications for the division, correlation, and definition of Paleogene lithological units in Nei Mongol (Inner Mongolia) /
no. 357
A new species of Forstercooperia (Perissodactyla, Paraceratheriidae) from northern China with a systematic revision of forstercooperiines
no. 389
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