''Aztlanolagus'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

rabbit Rabbits, also known as bunnies or bunny rabbits, are small mammals in the family Leporidae (which also contains the hares) of the order Lagomorpha (which also contains the pikas). ''Oryctolagus cuniculus'' includes the European rabbit speci ...

that lived during the

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ...

in what is now the Southern to Southwestern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

and northern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

. ''Aztlanolagus agilis'' is currently the only recognized species, though differences among recovered fossils suggest that there may have been other species. The generic name refers to Aztlán, the legendary place of origin of the Nahua peoples as recorded in the mythological accounts of the

Aztec The Aztecs () were a Mesoamerican culture that flourished in central Mexico in the post-classic period from 1300 to 1521. The Aztec people included different Indigenous peoples of Mexico, ethnic groups of central Mexico, particularly those g ...

s and other Nahua groups. By some traditions, this legendary locale is placed in the border regions of the

Southwestern United States The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural region of the United States that generally includes Arizona, New Mexico, and adjacent portions of California, Colorado, Ne ...

and adjacent northern

. Fossils range in age from the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

(

Blancan The Blancan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 4,750,000 to 1,806,000 years Before Present, BP, a period of .

to Rancholabrean North American land mammal ages). The known distribution is from southeastern

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

( Madrean Sky Islands region), to central

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

and from central

Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...

to southern

Chihuahua Chihuahua may refer to: Places *Chihuahua (state), a Mexican state **Chihuahua (dog), a breed of dog named after the state **Chihuahua cheese, a type of cheese originating in the state **Chihuahua City, the capital city of the state **Chihuahua Mun ...

''Aztlanolagus'' may be distinguished from all other known leporids as follows. Lower incisor terminates under diastema and well anterior to P₃. Three reentrant folds present on trigonid of P₃: an anterior reentrant fold, an anterointernal reentrant fold (rarely cut off to form an enamel lake), and an anteroexternal fold. At all growth stages, a posteroexternal reentrant fold extends approximately halfway across occlusal surface of P₃ to a narrow enamel lake lying next to lingual border; enamel lake rarely joined to external reentrant to form the ''Lepus''-type pattern (Hibbard, 1963). On P₄ to M₂, external fold extends to enamel of lingual wall. Anterior border of talonid on P₄-M₂ deeply convoluted, often with alternating series of major and minor enamel loops.... (Russell and Harris 1986:632-633)

Authority

The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

of ''Aztlanolagus agilis'' was deposited at the

University of Texas at El Paso The University of Texas at El Paso (UTEP) is a public research university in El Paso, Texas. It is a member of the University of Texas System. UTEP is the second-largest university in the United States to have a majority Mexican American stud ...

br>Biodiversity Collections
(Specimen No
UTEP:ES:1-1202
. The specimen, collected b
Richard A. Smartt
is a left dentary with

premolar The premolars, also called premolar teeth, or bicuspids, are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant in the permanent set of teeth, making eight premolars total in the mouth ...

s 3 and 4 and molars 1 and 2.

References

* Russell, Brett D., and Arthur H. Harris. 1986. A New Leporine (Lagomorpha: Leporidae) from Wisconsinan Deposits of the Chihuahuan Desert. Journal of Mammalogy 67(4):632-639, . * Winkler, A. J., and Y. Tomida. 1988. New records of the small leporid ''Aztlanolagus agilis'' Russell and Harris, Leporidae: Leporinae. Southwestern Naturalist 33:391-396. {{Taxonbar, from=Q16999880, from2=Q4832996 Pliocene mammals Pleistocene mammals Prehistoric lagomorphs Cenozoic mammals of North America Fossil taxa described in 1986 Chihuahuan Desert Fauna of the Rio Grande valleys Natural history of the Mexican Plateau Prehistoric placental genera