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1. chinaXiv:201802.00746 [pdf]

Reappraisal of Endotherium niinomii Shikama, 1947, a eutherian mammal from the Lower Cretaceous Fuxin Formation, Fuxin-Jinzhou Basin, Liaoning, China

WANG Yuan-Qing; KUSUHASHI Nao; JIN Xun; LI Chuan-Kui; SETOGUCHI Takeshi; GAO Chun-Ling; LIU Jin-Yuan
Subjects: Geosciences >> Geology

Reinvestigation of the Early Cretaceous eutherian mammal Endotherium niinomii Shikama, 1947, based on the impressions of the type specimen, casts made from the impressions, and the original description, indicates that E. niinomii is characterized by the following characters: decrease in size from the m1 to the m3; a moderate height difference between the trigonid and talonid of lower molars; blunt lower molar cusps; the protoconid being the largest among the trigonid cusps; the paraconid being as tall as the metaconid; the p3 not being obviously reduced; and possible possession of five lower premolars. These characteristics clearly distinguish E. niinomii from other known Cretaceous eutherians, and support its taxonomic identity as a valid taxon.

submitted time 2018-02-26 From cooperative journals:《古脊椎动物学报》 Hits4599Downloads1071 Comment 0

2. chinaXiv:201801.00584 [pdf]

Postcranial morphology of Middle Eocene deperetellid Teleolophus (Perissodactyla, Tapiroidea) from Shara Murun region of the Erlian Basin, Nei Mongol, China

BAI Bin; WANG Yuan-Qing; MENG Jin
Subjects: Geosciences >> Geology

Deperetellidae are a group of common, endemic Asian Middle Eocene tapiroids. Although five genera within the family have been named, most of them were represented by fragmentary maxillae and mandibles except for some skeletal material of Deperetella. Based exclusively on dental characters, different authors have proposed affinities of deperetellids with, for instance, helaletid Colodon, lophialetids, or rhodopagids. Here we described the partial postcranial skeleton of Teleolophus medius? recently discovered at Wulanhuxiu (=Ulan Shireh) of the Erlian Basin, China, and compared the postcranial skeletons of Teleolophus with those of Lophialetes, Deperetella, Heptodon, Helaletes, and Colodon. The postcranial skeleton of Teleolophus shares many similarities with that of Deperetella especially in having elongated and slender limbs, a relatively long, narrow lunar with a slightly concave medial border of the radial facet, a magnum with an anteriorly situated hump and a deeply excavated Mc IV facet, Mc II not elevated above Mc III, a slightly asymmetric trochlea of the femur, a fibula highly reduced or even fused with a tibia, Mt III contacting the cuboid, Mt II in contact with ectocuneiform only on the posterior end, and the manus and pes with functional tridactyls. These similarities support the close relationship between Teleolophus and Deperetella. We interpreted some similarities of postcrania between Teleolophus and Lophialetes as a result of parallel evolution, due to their cursorial adaptations. Colodon is more similar to Heptodon than to Teleolophus in the postcranial features, suggesting a close relationship between Colodon and Heptodon. Whether or not Helaletidae and Deperetellidae are closely related await further investigation. Both morphological characters and ternary diagram indicate that Teleolophus adapted to fast running, as its contemporary Lophialetes.

submitted time 2018-01-25 From cooperative journals:《古脊椎动物学报》 Hits4477Downloads1248 Comment 0

3. chinaXiv:201709.00122 [pdf]

Introduction to terminologies of tooth enamel microstructures and a proposal for their standard Chinese translations

MAO Fang-Yuan; LI Chuan-Kui; MENG Jin; LI Qian; BAI Bin; WANG Yuan-Qing; ZHANG Zhao-Qun; ZHAO Ling-Xia; WANG Ban-Yue
Subjects: Geosciences >> Geology

Tooth enamel is composed of elongated, hexagonal crystallites of hydroxyapatite. Some crystallites are arranged into various regual structures and futher formed a composite structure in a hierarchical manner. The hierarchical system can provide a basis for analysis different levels of structural complexity from varitaiton of particular crystallite strucutes to variation of structural types throughout a individual’s dentition. The size, orientation, distribution and the packing patterns of crystallites are gene-comtrolled and have limited range of intraspecific variability. Thus, these microstructures provide considerable and reliable morphological characters that help understanding of external dental morphology in context of both phylogeny and function in vertebrates. Because teeth are highly resistant to weathering, mainly owing to their enamel covering, so that they were commonly preserved as fossils. This organic system, particularly their microstructures, has attracted more and more attention from vertebrate paleontologists and other morphologists. However, as already recognized by many previous studies, some terminologies of the enamel microstructures have been complex and used inconsistently. Although considerable effort has been made to study enamel microstructures in China during the last few decades, a standard terminology of enamel microstructures in Chinese has not be formally brought into line with that in English literatures. Here we intend to introduce and systematize the relevant terminology used in the study of enamel microstructures and translate them into Chinese, in hoping that this systematic effort will enhance researches of enamel microstructures in China. 脊椎动物牙齿釉质显微结构具丰富的形态学特征,承载着系统发育和生物力学等方面的信息。本文在前人的研究基础上,试图系统地介绍牙釉质显微结构的基本内容,提出牙釉质研究中相关术语的中文译名建议,并对一些重要术语做了简要解释,供相关研究者参考,以期促进牙釉质显微结构研究的进一步发展。

submitted time 2017-09-28 From cooperative journals:《古脊椎动物学报》 Hits4746Downloads1491 Comment 0

4. chinaXiv:201707.00941 [pdf]

An ameghinornithid-like bird (Aves: Cariamae: Ameghinornithidae?) from the Middle Eocene of Nei Mongol, China

STIDHAM, Thomas A. ; WANG, Yuan-Qing
Subjects: Geosciences >> Geology

A new fossil specimen from the early Middle Eocene of an Irdin Manha Formation equivalent (Erden Obo Section) in Nei Mongol (Inner Mongolia), China appears to be derived from an ameghinornithid-like species, and may represent the frst record of the Ameghinornithidae in Asia. This new specimen exhibits the subcircular lateral condyle outline, the absence of an ossified supratendinal bridge, an enlarged flattened tubercle lateral to the extensor sulcus, and other features shared among known ameghinornithid and ameghinornithid-like birds. The Nei Mongol fossil is roughly contemporaneous with the oldest records of the ameghinornithids from Europe (~48 Ma). The absence of this group of birds from North America, and their occurrence in Europe and Asia during the Eocene contrasts with the contemporaneous Nei Mongol mammalian fauna that is comprised largely of Asian taxa with a few distinct linkages to North America. Along with the record of an ameghinornithid-like bird from the early Oligocene deposits of the Fayum area in Egypt, it seems that this extinct bird group had a much larger geographic distribution than previously recognized.

submitted time 2017-07-31 From cooperative journals:《古脊椎动物学报》 Hits1193Downloads403 Comment 0

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