Tongguer Fm

Central Inner Mongolia. Spock (29) didn’t assign its type section. Bureau of Geology and Mineral Resources of Nei Mongol Autonomous Region (BGMRNMAR)(1996) assigned a lectostratotype for this formation. The lectostratotype is located at the “Huerguojinlahasha (? Huerguolajin) section” (E113°04′, N43°47′), northeast of the Tongguer (=Tung Gur) tableland, west of Sonid Zuoqi County, central Nei Mongol. It was named by Spock (1929), a member of the Central Asiatic Expedition (CAE) (1921~1925) organized by the American Museum of Natural History (AMNH).

Synonym: Tung Gur Fm

There are two lithological types of the Tongguer Fm. In area of Huerguolajin, Moergen, Mandelin Chaba, Aoershun Chabu, “Wolf Camp”, and Zhunwuernan, its bottom is a layer of motley mudstone; its Lower part is characterized by greyish-white, greyish-green, and earthy brown mudstones and sandstones; its Middle part is formed by brick-red silty mudstones; its Upper part consists of greyish-white, yellowish-green, and light brown mudstones interbedded with muddy sandstones. In area of Tairum Nor, south of the Tongguer Tableland, its upper and lower parts are characterized by red mudstones, and its middle part consists of grey gravels. This formation contains abundant fossil charophytes, sporopollens, gastropods, mollusks, fishes, reptiles, and mammals. Its thickness is in range of 18~100 m.

Bivalvia: Lamprotula mongolica. Sporopollens: Polypodiisporites, Pinuspollenites, Abietineaepollenites, Ephedripites, Salixipollenites, Cyrillaceaepollenites, Quercoidites minor, Q. microhenrici, Q. henrici, Q. sp., Betulaceoipollenites, Rutaceoipollis, Operculumpollis, Labitricolpites, Ulmoideipites, Ulmipollenites, Polypoddisporites, Pterocaryapollenites, Juglanspollenites, Caryapollenites, Tricolpopollenites, Tilobapollis, Chenopodipollis, Graminidites, Artemisiaepollenites, Compositoipollenites. (Wang, 1990)

Mammals: Mioechinus? gobiensis, Erinaceinae gen. et sp. indet., Proscapanus sp., Yanshuella sp., Quyania sp., Desmanella storchi, Talpidae gen. et sp. indet., Mongolosorex qiui, Soricinae gen. et sp. indet., Soricidae gen. et sp. indet., Chiroptera gen. et sp. indet., Distylomys tedfordi, Ayakozomys ultimus, Ansomys Borealis, A. lophodens, Tamias ertemetensis, Atlantoxerus orientalis, Atlantoxerus sp., Sinotamias primitivus, Orientiglis wuae, Miodyromys asiamediae, Keramidomys fahlbuschi, Leptodontomys gansus, L. lii, Anchitheriomys tungurensis, Monosaulax tungurensis, Hystricops mengensis, Sicista ertemteensis, Heterosminthus orientalis, Protalactaga grabaui, P. major, Democricetodon lindsayi, D. tongi, Sonidomys deligeri, Megacrietodon sinensis, Cricetodon fengi, Plesiodipus leei, P. progressus, Gobicricetodon flynni, G. robustus, Desmatolagus? moergenensis, Alloptox gobiensis, Bellatona forsythmajori, Plithocyon teilhardi, Pseudarctos sp., Amphicyon tairumensis, Gobicyon macrognathus, Leptarctus neimenguensis, Aelurocyon? sp., Sthenictis sp., Melodon? sp., Mionictis sp., Martes sp., Tungurictis spocki, Percrocuta tungurensis, Metailurus mongoliensis, Sansanosmilus sp., Serridentinus gobiensis, Platybelodon granger, Zygolophodon sp., Anchitherium gobiensis, Chalicotherium brevirostris, Acerorhinus zernowi, Hispanotherium tungurense, Rhinocerotidae indet., Listriodon mongoliensis, Kubanochoerus sp., Palaeotragus tungurensis, Stephanocemas thomsoni, Stephanocemas sp., Lagomeryx triacuminates, Euprox grangeri, Dicrocerus sp., Micromeryx sp., Turcoceros granger, T. noverca. (Qiu, 1996; Wang et al., 2003; Qiu and Li, 2016).

It is interpreted as a river-lake environment.