''Sinobaatar'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of extinct

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

from the Lower

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. It is categorized within the also extinct order

Multituberculata Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct Order (biology), order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the M ...

and among these it belongs to the plagiaulacid lineage (a possible

infraorder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between Family_(biology), family and Class_(biology), class. In biological classification, the order is a taxonomic rank used in the classific ...

). ''Sinobaatar'' was a small

herbivore A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...

during the

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

era, commonly called "the age of the

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

s". The genus was named by Hu Y. and Wang Y. in 2002. Three species have been described. It has been found in Lower Cretaceous

strata In geology and related fields, a stratum (: strata) is a layer of Rock (geology), rock or sediment characterized by certain Lithology, lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by v ...

of the Yixian Formation in

Liaoning ) , image_skyline = , image_alt = , image_caption = Clockwise: Mukden Palace in Shenyang, Xinghai Square in Dalian, Dalian coast, Yalu River at Dandong , image_map = Liaoning in China (+all claims hatched).svg , ...

, China. According to Hu & Wang (2002),

" e dental features of ''Sinobaatar'' show again that eobaatarids are obviously intermediate between Late
Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...
multituberculates and the later forms".

Many Multituberculata are only known from teeth, but the

type specimen In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...

of ''Sinobaatar'' is a reasonably complete skeleton. A probable

tyrannosauroid Tyrannosauroidea (meaning 'tyrant lizard forms') is a superfamily (or clade) of coelurosaurian theropod dinosaurs that includes the family Tyrannosauridae as well as more basal relatives. Tyrannosauroids lived on the Laurasian supercontinen ...

specimen GMV 2124 (also known as NGMC 2124), previously attributed to ''

Sinosauropteryx ''Sinosauropteryx'' (meaning "Chinese reptilian wing") is an extinct genus of coelurosaurian theropod dinosaurs. Described in 1996, it was the first dinosaur taxon outside of Avialae (birds and their immediate relatives) to be found with eviden ...

'', contained a jaw of ''Sinobaatar'' in its stomach region.

Etymology

The name ''Sinobaatar'' is a

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

and

Mongolian Mongolian may refer to: * Something of, from, or related to Mongolia, a country in Asia * Mongolian people, or Mongols * Bogd Khanate of Mongolia, the government of Mongolia, 1911–1919 and 1921–1924 * Mongolian language * Mongolian alphabet * ...

mixture of "Sino–" and "Bataar" (

Baghatur Baghatur is a historical Turkic and Mongolic honorific title, in origin a term for "hero" or "valiant warrior". The Papal envoy Plano Carpini ( 1185–1252) compared the title with the equivalent of European Knighthood. The word was common am ...

) and means "Chinese hero". The type species name is in honor of Lingyuan City.

References

* Hurum, Jørn H.; Luo, Zhe-Xi & Kielan-Jaworowska, Zofia (2006): Were mammals originally venomous? ''Acta Palaeontologica Polonica'' 51(1): 1–11
PDF fulltext
* Kielan-Jaworowska, Zofia & Hurum, Jørn H. (2001): Phylogeny and Systematics of multituberculate mammals. ''Paleontology'' 44: 389–429. * Kusuhashi, Hu, Wang, Setoguchi & Matsuoka (2009): Two eobaatarid (Multituberculata; Mammalia) genera from the Lower Cretaceous Shahai and Fuxin Formations, Northeastern China. ''Journal of Vertebrate Paleontology'' 29(4): 1264–1288. * Hu & Wang (2002): ''Sinobaatar'' gen. nov.: First multituberculate from the Jehol Biota of Liaoning, Northeast China. ''Chinese Science Bulletin'' 47(11): 933–938. * Much of the above material has been derived fro

Cretaceous mammals Multituberculata Prehistoric animals of China Yixian fauna Prehistoric mammal genera {{cretaceous-mammal-stub