Taeniolabidoidea is a group of extinct

mammals Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

known from

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

and

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

. They were the largest members of the extinct order

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

, as well as the largest non-

theria Theria (; Greek: , wild beast) is a subclass of mammals amongst the Theriiformes. Theria includes the eutherians (including the placental mammals) and the metatherians (including the marsupials) but excludes the egg-laying monotremes. Ch ...

n mammals. '' Lambdopsalis'' even provides direct

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

evidence of mammalian

fur Fur is a thick growth of hair that covers the skin of mammals. It consists of a combination of oily guard hair on top and thick underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an insulating blanket t ...

in a fairly good state of preservation for a 60-million-year-old animal. Some of these animals were large for their time; '' Taeniolabis taoensis'' is the largest known multituberculate and though smaller, '' Yubaatar'' is the largest known Mesozoic Asian multituberculate.L. Xu, X. Zhang, H. Pu, S. Jia, and J. Zhang, J., and J. Meng. 2015. Largest known Mesozoic multituberculate from Eurasia and implications for multituberculate evolution and biology. Scientific Reports 5(14950):1-11 Average members of the Taeniolaboidea were about

beaver Beavers are large, semiaquatic rodents in the genus ''Castor'' native to the temperate Northern Hemisphere. There are two extant species: the North American beaver (''Castor canadensis'') and the Eurasian beaver (''C. fiber''). Beavers ar ...

-sized and the largest even reached sizes comparable to the largest beavers like ''

Castoroides ''Castoroides'' (Latin: "beaver" (castor), "like" (oides)), or giant beaver, is an extinct genus of enormous, bear-sized beavers that lived in North America during the Pleistocene. Two species are currently recognized, ''C. dilophidus'' in the S ...

'', up to about 100 kilograms. The group was initially established as a suborder, before being assigned the rank of a

superfamily SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...

by McKenna and Bell in 1997 (see Kielan-Jaworowska and Hurum (2001) p. 391-392). Two families are recognised: the primarily North American Taeniolabididae, composed of ''

Taeniolabis ''Taeniolabis'' ("banded incisor") is a genus of extinct multituberculate mammal from the Paleocene of North America. Description It is the largest known member of the extinct order Multituberculata, as well as the largest non-therian m ...

'' and '' Kimbetopsalis'', and the exclusively Asian Lambdopsalidae, composed of '' Lambdopsalis'', '' Sphenopsalis'' and '' Prionessus'', with '' Valenopsalis'' being a basal form outside of either clade. Some of the fossils are well-preserved. Though the possible taeniolabidoid '' Bubodens'' is known from the

Lancian The Lancian was a North American faunal stage of the Late Cretaceous. It was the final stage of the Cretaceous period in North America, lasting from approximately 70.6 to 66 million years ago. Geology Terrestrial sedimentary strata from the Judit ...

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

deposits of

South Dakota South Dakota (; Sioux language, Sioux: , ) is a U.S. state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota people, Lakota and Dakota peo ...

, and '' Yubaatar'' is known from Late Cretaceous deposits in the

Henan Province Henan (; or ; ; alternatively Honan) is a landlocked province of China, in the central part of the country. Henan is often referred to as Zhongyuan or Zhongzhou (), which literally means "central plain" or "midland", although the name is al ...

, the clade is otherwise only clearly represented in

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), E ...

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

. Derived characteristics of the

taxon In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

(apomorphies) include: "snout short and wide with anterior part of

zygomatic arch In anatomy, the zygomatic arch, or cheek bone, is a part of the skull formed by the zygomatic process of the temporal bone (a bone extending forward from the side of the skull, over the opening of the ear) and the temporal process of the zygomati ...

es directed transversely, resulting in a square-like shape of the skull (shared with

Kogaionidae Kogaionidae is a family of fossil mammals within the extinct order Multituberculata. Representatives are known from the Upper Cretaceous and the Paleocene of Europe. Having started as island endemics on Hateg Island during the Upper Cretaceous, ...

); frontals small, pointed posteriorly, almost or completely excluded from the orbital rim," (Kielan-Jaworowska and Hurum 2001, p. 417).

References

* Kielan-Jaworowska Z. and Hurum J.H., "Phylogeny and Systematics of multituberculate mammals". ''Paleontology'' 44, p. 389-429, 2001. * McKenna M.C. and Bell S.K., (1997), ''Classification of Mammals Above the Species Level''. Columbia University Press, 1997. * Much of this information has been derived fro

MESOZOIC MAMMALS:

Eucosmodontidae Eucosmodontidae is a poorly preserved family of fossil mammals within the extinct order Multituberculata. Representatives are known from strata dating from the Upper Cretaceous through the Lower Eocene of North America, as well as the Paleocene ...

Microcosmodontidae Microcosmodontidae is a poorly preserved family of fossil mammals within the extinct order Multituberculata. Representatives are known from the Lower Paleocene of North America. The family is part of the suborder Cimolodonta. Other than that, the ...

and Taeniolabidoidea, an Internet directory. {{Taxonbar, from=Q2474030 Multituberculates Paleocene extinctions Late Cretaceous first appearances