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1. chinaXiv:202104.00006 [pdf]

Climate change and evolution of early lagomorphs (Mammalia): a study perspective based on new materials of Ordolagus from Nei Mongol (northern China)

Subjects: Biology >> Zoology

The Early Oligocene is a critical time for global climate changes in the Cenozoic. This epoch witnessed severe mammalian faunal turnovers known as “Grande Coupure” in Europe and “Mongolian Remodelling” in Asia. However, insights about morphological changes in Oligocene mammal lineages have not been explored in detail. One of the least diversified groups of recent mammals, lagomorpha, is globally common in the fossil records, especially in Asia. During the Oligocene, many Eocene archaic lagomorph taxa died out and were replaced by more advanced forms. New findings from Nei Mongol and re-examination of the specimens from older collections enabled a revision of a common Asian lagomorph genus, Ordolagus, which possibly has a close affinity with the Middle–Late Eocene genus Gobiolagus. In Nei Mongol, we recognized the presence of Ordolagus during the basal Early Oligocene. Comparisons with coeval and slightly older lagomorph taxa from Asia and North America show that Ordolagus attained some salient tooth morphological characters (i.e., development of anteroconid on p3, full hypselodonty of cheek teeth, and lingual connection of trigonid and talonid on p4–m2), which are also the key features of modern leporids. The appearance of those morphologic features in Ordolagus is coeval to major global or regional climatic changes. Further investigations on Asian early lagomorphs compared with the study of other small mammals and local climatic factors will be essential to refine the role of lagomorphs as palaeoclimatic proxies.

submitted time 2021-04-02 From cooperative journals:《古脊椎动物学报》 Hits201Downloads98 Comment 0

2. chinaXiv:202104.00007 [pdf]

An Upper Miocene “Hipparion fauna” locality sandwiched by basalts in Hanjiaying, Nei Mongol

Subjects: Biology >> Zoology

Here we report a Hipparion fauna locality discovered in between two basalt layers near Hanjiaying Village, Jining District, Wulanchabu City, Nei Mongol. K-Ar isotopic dating of the lower and upper level of the basalt constrains the age of the fauna from 7.2 to 6.8 Ma. Compared with classical Hipparion fauna from northern China, the Hanjiaying fauna is closer to those from Baode of Shanxi, Siziwang Banner of Nei Mongol and the Linxia Basin of Gansu. It is similar to the Loc. 43, 44 and 49 from Baode by faunal composition, confirming their age to be ~7.0 Ma rather than 5.5 Ma. The high similarity with the fossils from Wulanhua, Siziwang Banner, Nei Mongol, verified the age of Wulanhua fauna at about 7 Ma. Compared with faunas from the Linxia Basin, Gansu, it is more similar to those from the upper part of the Liushu Formation, especially the Yangjiashan fauna. Based on the faunal composition and their tooth morphology, the Hanjiaying fauna could be included in the “Gazella dorcadoides” fauna, which is supposed to be at the west paleobiome in northern China during the Late Miocene.

submitted time 2021-04-02 From cooperative journals:《古脊椎动物学报》 Hits140Downloads58 Comment 0

3. chinaXiv:202009.00050 [pdf]

Late Miocene micromammalian assemblage of Tuchengzi and its biochronological position in Neogene faunal sequence in central Nei Mongol, China

ZHANG Li-Min; DONG Wei; Ni Xi-Jun; LI Qiang
Subjects: Biology >> Zoology

Neogene strata rich in fossil mammals are well exposed in central Nei Mongol, China. Over a dozen mammalian faunas in chronological succession from Early Miocene to Early Pliocene were discerned in this region, and they built a fundamental part of the Neogene land mammal biochronological system in northern China. Tuchengzi was first recognized for producing abundant mammalian fossils during the Sino-Soviet Paleontological Expedition (SSPE) initiated in 1959. However, all unearthed fossils from the SSPE were either large- or middle-sized mammals, and small mammal fossils in the Tuchengzi Fauna were deficient for a long time. The composition and biochronological position of the Tuchengzi Fauna in the Neogene mammalian biochronological system in northern China was not particularly clear. The new fossils here reported are represented by 6 taxa of small mammals. Based on the co-occurrence of Lophocricetus grabaui, Sinocricetus zdanskyi, Prosiphneus licenti, Hansdebruijnia pusilla, and Moschus grandaevus, the age of the Tuchengzi Fauna is constrained to late Late Miocene or Baodean Chinese Land Mammal Age, slighter younger than the Baogeda Ula Fauna and older than the Ertemte Fauna. Judging from the fossil composition, the Tuchengzi Fauna possibly inhabited a forest-steppe mixed habitat during the late Late Miocene.

submitted time 2020-09-15 From cooperative journals:《古脊椎动物学报》 Hits5794Downloads694 Comment 0

4. chinaXiv:202008.00034 [pdf]

Additional tsaganomyid, cylindrodontid and?ctenodactyloid rodent materials from the Erden Obo?section, Erlian Basin (Nei Mongol, China)

LI Qian
Subjects: Biology >> Zoology

To improve the Paleogene biochronological framework of the Erlian Basin, Nei Mongol?and clarify the diversity of fossil rodents in this region, new tsaganomyids (Cyclomylus lohensis,Coelodontomys asiaticus) from the “Upper White” beds, cylindrodontids (Gobiocylindrodon sp.,Proardynomys sp., and Cylindrodontidae gen. et sp. indet.) from the “Middle Red” and “Lower?Red” beds, and ctenodactyloids (Yuomys sp.) from the “Lower White” beds of the Erden Obo?section are reported. The appearance of C. lohensis and Co. asiaticus from the Erden Obo section?confirms that the age of the “Upper White” beds is Early Oligocene. The “Upper White” beds?of the Erden Obo section and the top bed of the Nom Khong Obo are confirmed to belong to the?same formation by both lithofacies and mammalian fossils. The different kinds of cylindrodontids?found from the different horizons of the Erden Obo section show that the cylindrodontids had a?high diversity and a relative continuous evolution in Eocene Asia.

submitted time 2020-08-02 From cooperative journals:《古脊椎动物学报》 Hits7838Downloads802 Comment 0

5. chinaXiv:201906.00025 [pdf]

The tetrapod fauna of the upper Permian Naobaogou?Formation of China— 4. the diversity of dicynodonts

Subjects: Biology >> Zoology

The Permian dicynodont records were previously rare in North China, but many?dicynodont specimens have been collected from the Naobaogou Formation in Daqingshan area,?Nei Mongol since 2009. Among these specimens, seven morphotypes have been identified, and?they may represent seven different species: two of them are closely related to Daqingshanodon?limbus, three or four are closely related to Jimusaria sinkianensis, and one may be closely related?to Turfanodon. This study shows the dicynodonts also have a high diversity at the species level in?North China.

submitted time 2019-06-11 From cooperative journals:《古脊椎动物学报》 Hits7990Downloads890 Comment 0

6. chinaXiv:201711.01910 [pdf]

New material of the Early Pleistocene mammalian fauna from Chutoulang, Chifeng, eastern Nei Mongol, China and binary faunal similarity analyses

DONG Wei; ZHANG Li-Min; LIU Wen-Hui
Subjects: Biology >> Zoology

New specimens from a new locality at Chutoulang in eastern Nei Mongol were identified as Canis chihliensis, Coelodonta nihowanensis, Hipparion (Proboscidipparion) sinense, Equus sanmeniensis, Sus lydekkeri, Muntiacus cf. M. lacustris, Axis shansius, Eucladoceros boulei, Spirocerus cf. S. wongi and Bison palaeosinensis. They enriched the mammalian fauna of Chutoulang to 30 taxa together with the material from Dongliang, Dongcun Beigou and Dongcun Nangou localities. The mammalian fossils from these four localities are all from the same horizon and can be regarded as the same fauna, i.e. Chutoulang fauna. The composition of Chutoulang fauna is the closest to that of Nihewan (s.s.) by binary faunal similarity coefficients. The age of Chutoulang fauna is between those of Nihewan (s.s.) and Juyuandong at Liucheng according to Brainerd-Robinson’s sequence, extinction rates and antiquity coefficients. The numerical age of Chutoulang fauna is estimated between 1.4–1.6 Ma based on those of compared faunas. Carnivora are the most numerous in Chutoulang fauna with 11 taxa, but mostly the small sized ones. Perissodactyla and Artiodactyla make about half of the fauna. They are mostly large sized forms. The presence of numerous browsers or forest dwellers implies the existence of forest or woodland in Chutoulang area during that period. The presence of grazers and openland dwellers indicates the existence of larger area of grassland or steppes than that of woodland or forests. Most members of Chutoulang fauna are temperate habitat dwellers with a few cold-prone forms such as Ochotona and Coelodonta. The climate in Chutoulang area in the Early Pleistocene was thus similar to that of today. Chutoulang fauna is the most northeastern Early Pleistocene fauna in China and it can be recommended as a type site of the Early Pleistocene mammalian fauna in northeastern China.

submitted time 2017-11-07 From cooperative journals:《古脊椎动物学报》 Hits2193Downloads1028 Comment 0

7. chinaXiv:201711.01919 [pdf]

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

Thomas A. STIDHAM ,WANG Yuan-Qing
Subjects: Biology >> Zoology

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 first 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 2017-11-07 From cooperative journals:《古脊椎动物学报》 Hits1154Downloads595 Comment 0

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