''Taeniolabis'' ("banded incisor") 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 ...

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

multituberculate 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 ...

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

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), ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Description

''Taeniolabis'' is a member of the

Taeniolabidoidea Taeniolabidoidea is a group of extinct mammals known whose fossils can be found in North America and Asia. They were the largest members of the extinct order Multituberculata, as well as the largest non-therian mammals. '' Lambdopsalis'' even pr ...

, a superfamily of multituberculates that are known for their highly derived teeth, and a short wide snout with a blocky head. The teeth modifications were likely an adaptation for

herbivory 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 n ...

that may have resulted from rapid diversification of

angiosperms Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit. T ...

at the very end of the

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 ...

, which would thus have created opportunities for novel specialization in herbivores. ''T. taoensis'' possessed an elongate, gently curved cochlear canal and an enlarged vestibule. It is the largest known multituberculate, as well as the largest allotherian mammal, with ''T. taoensis'' weighing up to . Species under this genus have been known under other names. ''Taeniolabis taoensis'' is found frequently enough and in a very limited time range that it can be used as an

index fossil Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. "Biostratigraphy." ''Oxford Reference: Dictionary of Biology ...

for the Puercan faunal stage within Danian aged fossil deposits.

Taxonomy

History

It is within the suborder of

Cimolodonta Cimolodonta is a clade of Multituberculata, multituberculate mammals that lived from the Cretaceous to the Eocene. They probably lived something of a rodent-like existence until their ecological niche was assumed by true rodents. The more basal ...

and is a member of the superfamily

. The genus was named by

Edward Drinker Cope Edward Drinker Cope (July 28, 1840 – April 12, 1897) was an American zoologist, paleontology, paleontologist, comparative anatomy, comparative anatomist, herpetology, herpetologist, and ichthyology, ichthyologist. Born to a wealthy Quaker fam ...

in 1882. Species have also been placed with the genera '' Catopsalis'' and ''Polymastodon''.

Species

* ''Taeniolabis lamberti'' was named by Nancy Simmons in 1987. It has been found in the

Danian The Danian is the oldest age or lowest stage of the Paleocene Epoch or Series, of the Paleogene Period or System, and of the Cenozoic Era or Erathem. The beginning of the Danian (and the end of the preceding Maastrichtian) is at the Cretac ...

aged Tullock Formation of

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

. It is not quite as large as ''T. taoensis'', but still a hefty size for a multituberculate, weighing around . Taeniolabis NT small

* ''Taeniolabis taoensis'' was originally named ''Taeniolabis sulcatus'' by Cope in 1882 as the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

of the genus. It was later renamed as ''T. taoensis''. Known fossils date to approximately 64 million years of age. They are found in

aged deposits of the Nacimiento Formation of

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

, the Ravenscrag Formation of

Saskatchewan Saskatchewan is a Provinces and territories of Canada, province in Western Canada. It is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and to the south by the ...

and the Denver Formation of Colorado. This species likely had a roughly long skull and had an average body mass of , which is approximately the size of a modern

beaver Beavers (genus ''Castor'') are large, semiaquatic rodents of the Northern Hemisphere. There are two existing species: the North American beaver (''Castor canadensis'') and the Eurasian beaver (''C. fiber''). Beavers are the second-large ...

. The species was once considered to have had a body mass of up to 100 kg and sized like a sheep or larger by extrapolating body size on the basis of their huge teeth. However, improved analyses and the realization that the teeth were extraordinarily robust due to herbivory rather has generally disproved that.Wilson et al, 2012 Supplemental Table 5

Notes

References