Browsing by Author "Meng, Jin (Paleontologist)"
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- ItemAge and correlation of fossiliferous late Paleocene-early Eocene strata of the Erlian Basin, Inner Mongolia, China. American Museum novitates ; no. 3474(New York, NY : American Museum of Natural History, 2005) Bowen, Gabriel J.; Koch, Paul L.; Meng, Jin (Paleontologist); Ye, Jie.; Ting, Su-Yin.The Asian continent preserves a rich and diverse record of Paleogene mammal faunas and their evolution through time. The sequence of faunal succession is of key importance to our understanding of the origin and diversification of modern mammal groups, as phylogenetic data suggest that many major modern clades may be rooted in Asia. By calibrating the Asian fauna sequence within a chronostratigraphic framework, we can begin to compare patterns of succession on a global scale and constrain models for the origination and dispersal of modern mammal groups in the early Paleogene. The Erlian Basin of Inner Mongolia preserves early Paleogene strata and mammal fossils assignable to the Gashatan, Bumbanian, and Irdin Manhan Asian Land Mammal Ages (ALMAs). We measured stratigraphic sections and analyzed the stable isotope composition of paleosol carbonates and paleomagnetic directions of rocks at three localities in the Erlian Basin. The data document patterns in lithology, carbon isotope composition, and magnetic polarity that are consistent at all three localities and allow us to present two constrained hypotheses for the correlation of the local stratigraphic sections. Within the resulting composite section, we are able to identify a secular decrease in the carbon isotope composition of paleosol carbonate that can be equated to a multimillion-year trend preserved in late Paleocene and early Eocene terrestrial and marine records. Using this trend and previously documented constraints on the age of the Bumbanian ALMA, the composite section is shown to correlate within the interval of time represented by chrons C26n-C24n of the Geomagnetic Polarity Timescale (GPTS). We outline three possible correlations of the sequence of magnetic polarity zones in our composite section to the GPTS and explore the biostratigraphic implications of these. All three possible correlations show that Gashatan faunas in Inner Mongolia occur within chron C24R, and the preferred correlation suggests that the Gashatan taxa may have persisted close to the Paleocene/Eocene boundary. If confirmed through further sampling, this result would imply that the first appearance of the modern mammal orders Primates, Artiodactyla, and Perissodactyla in Asia at the base of the Bumbanian ALMA did not significantly precede their first appearances in Europe and North America at the Paleocene/Eocene boundary. Fossil sites in the Erlian Basin promise to be central to resolving the debate about whether these clades lived and diversified in Asia before dispersing throughout the Northern Hemisphere at the Paleocene/Eocene boundary.
- ItemBiostratigraphy and diversity of Paleogene perissodactyls from the Erlian Basin of Inner Mongolia, China.(American Museum of Natural History., 2018-12-14) Bai, Bin, 1981-; Wang, Yuan-qing.; Li, Qian (Paleontologist); Wang, Hai-bing.; Mao, Fang-yuan.; Gong, Yan-xin.; Meng, Jin (Paleontologist)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.
- ItemCranial and postcranial morphology of the insectivoran-grade mammals Hsiangolestes and Naranius (Mammalia, Eutheria) : with analyses of their phylogenetic relationships (Bulletin of the American Museum of Natural History, no. 463)(American Museum of Natural History., 2023-06-26) Ting, Suyin; Wang , Xiaoming (Paleontologist); Meng, Jin (Paleontologist)Early Cenozoic “insectivorans” possess some of the most primitive morphologies among eutherian mammals. Studies of these archaic mammals offer insights into the early diversifications of basal eutherians. Despite such importance, early fossil “insectivorans” from Asia are poorly known due to a scarcity of fossil remains, which often consist only of fragmentary jaws and teeth. Discoveries of remarkably well-preserved fossil “insectivorans”, including complete skulls and articulated postcranial skeletons, from the early Eocene Hengyang Basin in south-central Hunan Province, China, offer a rare opportunity to thoroughly study two taxa belonging to different families. Fine-grained red beds from Hengyang Basin preserve extraordinary fossils with morphological structures rarely seen elsewhere. Thin sections of a skull of Hsiangolestes youngi Zheng and Huang, 1984, for example, reveal the extremely delicate nasal and maxillary turbinates, which, as far as we are aware, are the first known from fossils of this age. We thus take this opportunity to document in detail the cranial and dental morphology, as well as postcranial skeletons, of the Hengyang “insectivorans”. In this monograph, we describe several complete skulls and serial sections of a skull, as well as many partial skulls, mandibles, and postcranial skeletons of Hsiangolestes youngi, an Asian early Eocene insectivoran-grade mammal. We also report a new species of Naranius Russell and Dashzeveg, 1986—N. hengdongensis—an Asian early Eocene cimolestid and describe its well-preserved skulls and mandibles. Hsiangolestes is endemic to Asia. It is currently known only from the earliest Eocene Lingcha Formation, Hengyang Basin, Hunan Province, China. Naranius closely resembles Cimolestes Marsh, 1889, the type genus of the family Cimolestidae. It is mainly distributed in Asia and known from the earliest Eocene deposits in the Bumban Member of the Naran Bulak Formation, Nemegt Basin, of Mongolia, and the Lingcha Formation, Hengyang Basin, Hunan Province, China. The only record of Naranius reported outside of Asia is N. americanus from the early Wasatchian Red Hot Local Fauna, Mississippi, United States. Using PAUP and TNT search algorithms, we place these Hengyang taxa within phylogenetic context of other fossil “insectivorans” from the Mesozoic and early Cenozoic of Asia together with some well-known Holarctic taxa. A phylogenetic analysis of 290 cranial and dental characters from 36 fossil and modern insectivoran-grade taxa is presented, focusing on new materials of Hsiangolestes youngi and Naranius hengdongensis. Based on the results of our phylogenetic analyses, we propose that (1) Hsiangolestes, Prosarcodon, Sarcodon, and Sinosinopa, form a monophyletic group, for which we propose the family name Sarcodontidae; (2) the family Cimolestidae should be restricted to Naranius and Cimolestes, which are sister taxa; (3) the systematic position of Naranius americanus is uncertain; and (4) the family Micropternodontidae should be restricted to Micropternodus and its allies in North America.
- ItemDiscovery of the first early Cenozoic euprimate (Mammalia) from Inner Mongolia ; American Museum novitates, no. 3571(New York, NY : American Museum of Natural History, 2007) Ni, Xijun.; Beard, K. Christopher.; Meng, Jin (Paleontologist); Wang, Yuan-qing.; Gebo, Daniel Lee, 1955-Although it is widely thought that euprimates originated in Asia, the fossil record of early euprimates remains sparse there. We describe herein a new omomyid euprimate, Baataromomys ulaanus, n. gen. et sp., based on an isolated right lower m2 from Bumbanian strata at Wulanboerhe in the Erlian Basin of Inner Mongolia, China. In terms of the size and proportions of m2, Baataromomys ulaanus is intermediate between Eurasian and North American species that are usually assigned to Teilhardina. Morphologically, m2 of Baataromomys differs from that of Teilhardina and North American small-bodied omomyids (including Anemorhysis, Tetonoides, Trogolemur, and Sphacorhysis) in having a smaller paraconid that is less fully connate with the metaconid, a lower entoconid, a weaker crest connecting the metaconid with the entoconid, and a weaker buccal cingulid. The new taxon is much smaller and lower crowned than Steinius, a genus commonly regarded as a basal omomyid. Despite the substantial difference in size, the m2s of Baataromomys and Steinius share some important features, including a very broad talonid basin and a relatively low hypoconid and cristid obliqua. Given its early occurrence and primitive anatomy, Baataromomys may eventually help to clarify the phylogenetic relationships among basalomomyids, but more complete specimens will be required to test this possibility. Baataromomys brandti from the basal Wasatchian zone Wa-0 in the northern Bighorn Basin, Wyoming, was previously allocated to Teilhardina. However, several dental features shared by B. brandti and B. ulaanus suggest that they are closely related. The co-occurrence of Baataromomys in Asia and North America indicates that small-bodied euprimates were able to dispersal across the Beringian region near the Paleocene-Eocene boundary.
- ItemGlires (Mammalia) from the late Paleocene Bayan Ulan locality of Inner Mongolia. American Museum novitates ; no. 3473(New York, NY : American Museum of Natural History, 2005) Meng, Jin (Paleontologist); Wyss, André R.; Hu, Yaoming.; Wang, Yuanqing.; Bowen, Gabriel J.; Koch, Paul L.Two new early diverging members of Glires, Eomylus bayanulanensis, n.sp. and Palaeomylus lii, n.gen. and n.sp., are described from the late Paleocene Bayan Ulan Fauna, Inner Mongolia, China. These species add significantly to the diversity of Glires known from the early Paleogene of Asia. E. bayanulanensis and Palaeomylus sp. come from the lowest level of the Bayan Ulan section, from which the classic Bayan Ulan Fauna was collected. Palaeomylus lii and specimens belonging to two other genera of mammals, Pseudictops and Palaeostylops, are found from a horizon about 8 m above strata yielding the Bayan Ulan Fauna. These taxa are tentatively regarded as constituting a distinct faunal assemblage, which may prove to be of biostratigraphic utility within the region. Two calcanea tentatively assigned to Gomphos from a stratigraphic horizon slightly above the bed producing P. lii suggest the presence of strata of early Eocene age in the Bayan Ulan section.
- ItemGomphos elkema (Glires, Mammalia) from the Erlian Basin : evidence for the early Tertiary Bumbanian land mammal age in Nei-Mongol, China. American Museum novitates ; no. 3425(New York, NY : American Museum of Natural History, 2004) Meng, Jin (Paleontologist); Bowen, Gabriel J.; Ye, Jie.; Koch, Paul L.; Ting, Su-Yin.; Li, Qian (Paleontologist); Jin, Xun (Paleontologist)Dental and postcranial specimens of Gomphos elkema, including lower and upper dentition and pedal elements, from the Huheboerhe locality, Erlian Basin, Nei-Mongol (Inner Mongolia), are described. Postcranial elements of Gomphos are similar to those of Mimolagus, suggesting affinity with lagomorphs. Gomphos elkema is a typical Bumbanian taxon, previously known only from Mongolia. Gomphos elkema specimens at Huheboerhe indicate occurrence of Bumbanian-equivalent beds and fauna in the region and suggest potential presence of the Paleocene-Eocene boundary in the Huheboerhe section.
- ItemNew craniodental materials of Litolophus gobiensis (Perissodactyla, "Eomoropidae") from Inner Mongolia, China, and phylogenetic analyses of Eocene chalicotheres. (American Museum novitates, no. 3688)(American Museum of Natural History., 2010) Bai, Bin, 1981-; Wang, Yuan-qing.; Meng, Jin (Paleontologist)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.
- ItemNew ctenodactyloid rodents from the Erlian Basin, Nei Mongol, China, and the phylogenetic relationships of Eocene Asian ctenodactyloids. (American Museum novitates, no. 3828)(American Museum of Natural History., 2015-03-20) Li, Qian (Paleontologist); Meng, Jin (Paleontologist)During the last decade, numerous ctenodactyloid rodent fossils have been systematically collected from at least six horizons of the strata that are distributed from the upper part of the Nomogen Formation to the lower part of the Irdin Manha Formation in the Huheboerhe-Nuhetingboerhe area of the Erlian Basin, Nei Mongol (Inner Mongolia). The ages of these fossiliferous horizons range from the Earliest Eocene to the Middle Eocene. These fossils represent the best-known ctenodactyloid assemblages with a high species diversity and reliable stratigraphic and chronological constraints from one locality in central Asia. The fossils show a relatively continuous record of ctenodactyloids and the earliest radiation of rodents in central Asia beginning from the earliest Eocene. These data are important for biostratigraphic correlation of the Paleogene in central Asia and for understanding the taxonomy of Asian ctenodactyloids and the earliest diversity and evolution of rodents. Among the new fossils, we recognized 10 species that belong to six genera and three morphotypes. Of these taxa, three new genera and species, Chenomys orientalis, gen. et sp. nov., Simplicimys bellus, gen. et sp. nov., and Yongshengomys extensus, gen. et sp. nov., are described. In addition, three new species of Tamquammys, T. robustus, sp. nov., T. longus, sp. nov., and T. fractus, sp. nov., and one new species of Yuomys, Y. huheboerhensis, sp. nov., are also named. With these new materials, we are able to briefly review some existing problems in the taxonomy of early ctenodactyloids, which has remained a difficult task in the study of this Asian rodent group. In light of the new material and taxonomic review, we conducted phylogenetic analyses of ctenodactyloids using a data matrix that contains 38 taxa and 81 characters. Our analysis shows that Chenomys, Tamquammys, and Simplicimys are placed at the base of the clade that contains the extant Ctenodactylus. Yongshengomys is the only taxon that is deeply placed within the clade containing the extant Ctenodactylus and clustered with Chuankueimys and Tsinlingomys. Our analysis supports Gobiomyidae and Ctenodactylidae as monophyletic groups, respectively, but shows that other families and subfamilies traditionally recognized, such as Cocomyinae, Advenimurinae, Tamquammyidae, Yuomyidae, and Chapattimyidae, are probably paraphyletic.
- ItemNew distylomyid rodents (Mammalia, Rodentia) from the early Miocene Suosuoquan Formation of northern Xinjiang, China. (American Museum novitates, no. 3663)(New York, NY : American Museum of Natural History., 2009) Bi, Shundong.; Meng, Jin (Paleontologist); Wu, Wenyu.; Ye, Jie.; Ni, Xijun.Three new distylomyid species, Distylomys burqinensis, Prodistylomys wangae, and P. lii, are described from the Suosuoquan Formation, early Miocene, of Xinjiang Province, northwestern China. Previously unknown cranial materials and upper dentitions add new information for the higher-level taxonomy of distylomyid rodents. Based on these new discoveries, the family Distylomyidae is resurrected. These fossils demonstrate that distylomyids have a combination of primitive "ctenodactylid" characters and derived hystricognathous ones, possibly indicating a close affinity with South American caviomorph rodents and thereby offering new evidence to challenge the hypothesis that the traditional "Ctenodactyloidea" are monophyletic. Prodistylomys lii was recovered from Suosuoquan mammal assemblage III (magnetostratigraphically dated as 21.69-21.16 Mya) at the Chibaerwoyi locality. Distylomys burqinensis and Prodistylomys wangae were collected from a new fossiliferous locality, Locality XJ200601 of Burqin County. The composition of the fauna from this new locality suggests that it represents an assemblage younger than Suosuoquan mammal assemblage III. Preliminary comparison with other faunas suggests that the assemblage is of early Miocene age, approximately 20 Mya old, and is a new fossil level within the Suosuoquan Formation.
- ItemNew Eocene ctenodactyloid rodents from the eastern Gobi Desert of Mongolia and a phylogenetic analysis of ctenodactyloids based on dental features. American Museum novitates ; no. 3246(New York, NY : American Museum of Natural History, 1998) Dashzėvėg, Dėmbėrėliĭn.; Meng, Jin (Paleontologist); Mongolian-American Museum Paleontological Project.; Mongolyn Shinzhlėkh Ukhaany Akademi.Two ctenodactyloid rodents, Mergenomys orientalis, n. gen. and sp., and Butomys prima, n. gen. and sp., from the middle Eocene localities of the eastern Gobi Desert of Mongolia are described. Dental features that bear phylogenetic importance for ctenodactyloids are discussed. A cladistic analysis based primarily on dental features reveals the phylogenetic positions of the two new taxa. Mergenomys is closely related to the clade of the Ctenodactylidae, whereas Butomys is possibly related to Tsinlingomyinae. The analysis indicates that several traditional taxa of ctenodactyloids, such as Cocomyidae and Yuomyidae, are paraphyletic.
- ItemA new Eocene cylindrodont rodent (Mammalia, Rodentia) from the eastern Gobi of Mongolia. American Museum novitates ; no. 3253(New York, NY : American Museum of Natural History, 1998) Dashzėvėg, Dėmbėrėliĭn.; Meng, Jin (Paleontologist); Mongolian-American Museum Paleontological Project.; Mongolyn Shinzhlėkh Ukhaany Akademi.A new genus and species of cylindrodont rodents, Proardynomys borkhoii, from the middle Eocene Mergen locality of the eastern Gobi, Mongolia, is among the earliest cylindrodontids of Asia. Comparisons with cylindrodontids, sciurids, aplodontids, ischyromyids, and ctenodactyloids show that P. borkhoii is most similar to Ardynomys olseni of the Cylindrodontidae in having the p4 trigonid basin open anteriorly; the lower molars with two anterior and one posterior root; the metalophid II extending from the protoconid toward the metaconid and enclosing a small trigonid basin; a short ectolophid bearing no mesoconid; the hypoconid projecting anterolabially; the entoconid separated from the posterolophid but connected with the ectolophid in front of the hypoconid by a complete hypolophid; the metastylid crest and entoconid separated by a narrow gap at the lingual edge of the tooth; a strong posterolophid bearing no hypoconulid; and the lower incisor with uniserial enamel ultrastructure. It differs from A. olseni in having a rounded ventral surface on the lower incisor; the molar teeth lower crowned and the trigonid higher than the talonid; the lophs and lophids narrower and less well developed; the hypoconid not unicuspal hypsodont; the anterior part of the talonid basin wide open; and a lower metastylid crest bordering the lingual margin of molars. A recent proposal of a sister group relationship between Cylindrodontidae and Ctenodactylidae is reviewed and is rejected because of insufficient evidence. The possibility that the Cylindrodontidae are related to sciuromorphs, particularly Sciuridae and Aplodontidae, is speculated; these taxa may have been derived from an ischyrornyid stock.
- ItemA new Eocene rodent from the lower Arshanto Formation in the Nuhetingboerhe (Camp Margetts) area, Inner Mongolia ; American Museum novitates, no. 3569(New York, NY : American Museum of Natural History, 2007) Meng, Jin (Paleontologist); Li, Chuan-Kuei.; Ni, Xijun.; Wang, Yuan-qing.; Beard, K. Christopher.A new miniscule rodent represented by isolated cheek teeth is reported from the lower part of the late early Eocene Arshanto Formation, Nuhetingboerhe (Camp Margetts) area, Inner Mongolia. A new family, based on the new genus and species, is proposed. The new taxon resembles alagomyids but differs from early rodents in having a partial buccal cingulum, a distinct metaconule that merges posteriorly with the postcingulum, a transversely oriented trigon basin that widely separates the paracone and metacone, a prominent hypoconulid on lower molars, and in lacking the hypocone and protocristid. It differs from alagomyids in having a greater length/width ratio of upper cheek teeth, a neomorphic cusp termed as the preprotoconule, a preprotoconule crista that projects anteriorly, an anteroconid on dp4, an oblique cristid obliqua bearing a distinct mesoconid, and the hypoconid more posteriorly extended (or hypoconulid less posteriorly extended) on m3. The dental morphology of the new taxon is derivable from analagomyid dental pattern and is intermediate between alagomyids and rodents of modern aspect; it casts new light on the evolution of dentition of early rodents.
- ItemNew material of Alagomyidae (Mammalia, Glires) from the late Paleocene Subeng locality, Inner Mongolia ; American Museum novitates, no. 3597(New York, NY : American Museum of Natural History, 2007) Meng, Jin (Paleontologist); Ni, Xijun.; Li, Chuan-Kuei; Beard, K. Christopher.; Gebo, Daniel Lee, 1955-; Wang, Yuan-qing.; Wang, Hongjiang.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.
- ItemNew material of Eocene Helaletidae (Perissodactyla, Tapiroidea) from the Irdin Manha Formation of the Erlian Basin, Inner Mongolia, China, and comments on related localities of the Huheboerhe area. (American Museum novitates, no. 3878)(American Museum of Natural History., 2017-04-14) Bai, Bin, 1981-; Wang, Yuan-qing.; Mao, Fang-yuan.; Meng, Jin (Paleontologist)Perissodactyls first appeared at the beginning of the early Eocene and reached their highest diversity, dominating contemporaneous mammalian faunas in species richness during the middle Eocene. Tapiroidea is an important perissodactyl group that includes earliest-Eocene forms, such as Orientolophus as well as extant taxa (such as Tapirus), that preserves numerous plesiomorphic characters. Because tapiroids were widely distributed in North America and Asia in the middle Eocene, they have played an important role in biostratigraphically defining middle Eocene North American Land Mammal Ages (NALMA) and Asian Land Mammal Ages (ALMA), respectively, as well as in biostratigraphic correlation between the two continents. Here we report a new cranial specimen of middle Eocene helaletid Paracolodon fissus and a maxilla of Desmatotherium mongoliense from the middle Eocene Irdin Manha Formation of the Erlian Basin, Inner Mongolia, China. Paracolodon fissus was previously assigned to Desmatotherium, Helaletes, or Colodon, whereas D. mongoliense was assigned to Helaletes or Irdinolophus by different authors. Based on the new material described in this report, we are able to clarify the affinities and phylogenetic position of these species according to morphological comparison and phylogenetic analyses. We maintain the genus Paracolodon for P. inceptus and P. fissus from Asia and reassign mongoliense to Desmatotherium. Fossils of perissodactyls and other groups from the Irdin Manha Formation favor correlation of the Irdinmanhan ALMA with the early and middle Uintan NALMA (Ui1-Ui2). Through our field investigation, we also clarified that the localities "7 miles southwest" and "10 miles southwest" of Camp Margetts, originally used by the American Museum of Natural History's Central Asiatic Expedition (CAE), correspond to the localities currently known as Huheboerhe and Changanboerhe, respectively.
- ItemA new species of Chungchienia (Tillodontia, Mammalia) from the Eocene of Lushi, China. American Museum novitates ; no. 3171(New York, N.Y. : American Museum of Natural History, 1996) Chow, Min-Chen.; Wang, Jingwen (Paleontologist); Meng, Jin (Paleontologist)
- ItemA new species of Forstercooperia (Perissodactyla, Paraceratheriidae) from northern China with a systematic revision of forstercooperiines. (American Museum novitates, no. 3897)(American Museum of Natural History., 2018-03-21) Wang, Hai-Bing.; Bai, Bin, 1981-; Meng, Jin (Paleontologist); Wang, Yuan-qing.Forstercooperiines are a group of large, primitive rhinocerotoids that are commonly regarded as ancestral to later giant rhinos. However, the type genus of forstercooperiines, the Middle Eocene Forstercooperia, is one of the most poorly known rhinocerotoids, and is represented only by fragmentary material. Here we name a new species, Forstercooperia ulanshirehensis, based on five specimens, including a well-preserved cranium and a pair of complete mandibles. This new material was collected from the Ulan Shireh Formation in the western part of the Erlian Basin and the Irdin Manha Formation in the eastern part of the Erlian Basin, northern China. These specimens provide the most complete craniodental remains of Forstercooperia sensu stricto (excluding Pappaceras), and on this basis the species-level taxonomy of forstercooperiines is thoroughly revised and six species of two genera are considered as valid. Specimens previously assigned to "Forstercooperia minuta" are reassigned to different species based on the revised diagnoses. All equivocal specimens that were thought to have an affinity with Forstercooperiinae are briefly discussed. Based on a new character matrix, phylogenetic analyses fully resolve the relationships of early rhinocerotoids, including the recovery of Forstercooperia and Pappaceras as sister groups. The occurrence of Forstercooperia ulanshirehensis in the eastern and western Erlian Basin is indicative of age correlation between the lower part of the Ulan Shireh Formation and the Irdin Manha Formation.
- ItemA new species of Gomphos (Glires, Mammalia) from the Eocene of the Erlian Basin, Nei Mongol, China. (American Museum novitates, no. 3670)(New York, NY : American Museum of Natural History., 2009) Meng, Jin (Paleontologist); Kraatz, Brian P.; Wang, Yuan-qing.; Ni, Xijun.; Gebo, Daniel Lee, 1955-; Beard, K. Christopher.Dental and postcranial specimens of Gomphos shevyrevae, sp. nov., from the lower part of the Irdin Manha Formation at the Huheboerhe locality, Erlian Basin, Nei Mongol (Inner Mongolia), are described. The new species differs from G. elkema and G. ellae in having more robust teeth with inflated cusps and stronger lophs and a calcaneus with extra articulation for the astragalus and navicular. The new species is stratigraphically well constrained and probably represents the youngest known species of the genus, extending its geological record into the Middle Eocene. It also shows that mimotonids coexisted for millions of years as a side branch of duplicidentates with the earliest stem lagomorphs, including Dawsonolagus.
- ItemA new species of Megacricetodon (Cricetidae, Rodentia, Mammalia) from the Middle Miocene of northern Junggar Basin, China ; American Museum novitates, no. 3602(New York, NY : American Museum of Natural History, 2008) Bi, Shundong.; Meng, Jin (Paleontologist); Wu, Wenyu.Dental, mandibular, and postcranial specimens of Megacricetodon yei n. sp., are described. The new specimens, including the complete dentition, mandible, and partial forelimb and hindlimb, represent the most complete materials known for the genus, provide valuable information concerning the interspecific variation of the genus, and lead to the reassessment of the suprageneric position of Megacricetodon. Megacricetodon yei is characterized by having medium-size, clearly split anterocone of M1, presence of the labial spur of the anterolophule and the posterior spur of the paracone in some M1s, medium to long mesoloph in M1-2, frequent occurrences of double protolophules, transverse or posteriorly directed metalophule of M2, and single anteroconid of the m1. Megacricetodon yei is more closely related to Megacricetodon (= Aktaumys) dzhungaricus than to any other species of Megacricetodon, but is more derived than the latter. Based on the new information, the validity of the genus Aktaumys is discussed. The postcranial features of Megacricetodon yei show clear adaptations for terrestrial habits, but as in many ground-dwelling rodents living in burrows, it could also climb or dig. The associated fauna has been correlated to Tongxin fauna from the adjacent part of China and the Belometchetskya fauna of north Caucasus, equivalent to early Middle Miocene age, or MN 6 correlative. The stage of evolution of Megacricetodon yei is consistent with the faunal correlation. Dental, mandibular, and postcranial specimens of Megacricetodon yei n. sp., are described. The new specimens, including the complete dentition, mandible, and partial forelimb and hindlimb, represent the most complete materials known for the genus, provide valuable information concerning the interspecific variation of the genus, and lead to the reassessment of the suprageneric position of Megacricetodon. Megacricetodon yei is characterized by having medium-size, clearly split anterocone of M1, presence of the labial spur of the anterolophule and the posterior spur of the paracone in some M1s, medium to long mesoloph in M1-2, frequent occurrences of double protolophules, transverse or posteriorly directed metalophule of M2, and single anteroconid of the m1. Megacricetodon yei is more closely related to Megacricetodon (5 Aktaumys) dzhungaricus than to any other species of Megacricetodon, but is more derived than the latter. Based on the new information, the validity of the genus Aktaumys is discussed. The postcranial features of Megacricetodon yei show clear adaptations for terrestrial habits, but as in many ground-dwelling rodents living in burrows, it could also climb or dig. The associated fauna has been correlated to Tongxin fauna from the adjacent part of China and the Belometchetskya fauna of north Caucasus, equivalent to early Middle Miocene age, or MN 6 correlative. The stage of evolution of Megacricetodon yei is consistent with the faunal correlation.
- ItemNew stratigraphic data from the Erlian Basin : implications for the division, correlation, and definition of Paleogene lithological units in Nei Mongol (Inner Mongolia) ; American Museum novitates, no. 3570(New York, NY : American Museum of Natural History, 2007) Meng, Jin (Paleontologist); Wang, Yuan-qing.; Ni, Xijun.; Beard, K. Christopher.; Sun, Chengkai.; Li, Qian (Paleontologist); Jin, Xun (Paleontologist); Bai, Bin, 1981-Newly measured stratigraphic sections are reported for Paleogene rocks in the Nuhetingboerhe-Huheboerhe (Camp Margetts) area of Nei Mongol (Inner Mongolia), China. The composite sequence in this region is 82.4 m thick, encompassing three lithological units separated by important depositional hiatuses. In stratigraphic order, these rock units correspond to the Nomogen, Arshanto and Irdin Manha formations. The sequence contains faunas from four Asian land-mammal "ages", the Gashatan, Bumbanian, Arshantan, and Irdinmanhan, which together span the interval from late in the late Paleocene to early in the middle Eocene. Comparisons with localities and sections documented since the time of the Central Asiatic Expeditions (CAE) show that the so-called Houldjin gravels of the CAE from this area are mostly Irdin Manha Formation and that the "Irdin Manha beds" of the CAE belong to the Arshanto and/or Nomogen formations. These findings reveal that previous concepts of the Irdin Manha and Arshanto faunas from the Camp Margetts area probably include fossils of different ages, so that the corresponding Asian land-mammal "ages" based on these faunas are problematic and need systematic revision. The Nomogen, Arshanto, and Irdin Manha formations are redefined.
- ItemThe osteology of Matutinia (Simplicidentata, Mammalia) and its relationship to Rhombomylus. American Museum novitates ; no. 3371(New York, NY : American Museum of Natural History, 2002) Ting, Su-Yin.; Meng, Jin (Paleontologist); McKenna, Malcolm C.; Li, Chuan-Kuei.New dental, cranial, and postcranial specimens of the eurymylid Matutinia nitidulus from the early Eocene Lingcha Formation, Hengyang Basin, Hunan Province, China, are described. These materials are among the best of basal gliroid mammals from Asia. Matutinia is similar to Rhombomylus in general tooth and cranial morphologies, including an expanded hypocone shelf on the upper cheek teeth and a complex zygomatic arch. These features distinguish the two genera from other eurymylids such as Heomys and Eurymylus. Matutinia differs from Rhombomylus in having lower crowned and less lophate cheek teeth, fewer bony septa in the mastoid chamber, a lower promontorium, and a carotid foramen in the ear region. Based on the new material, we consider Matutinia a valid genus, not a junior synonym of Rhombomylus.