''Villarroelia'' is an extinct

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 ...

of proterotheriid from the Middle Miocene of

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

Etymology

The genus name, ''Villarroelia'' refers to the paleontologist Carlos Villarroel, for his contributions to the understanding of prehistoric South American mammals, while the specific name, ''V. toyotoi'' refers to the indigenous chief Toyotó, whose tribe was present in the area of the Villavieja River, in the present-day

Huila Department Huila () is one of the departments of Colombia. It is located in the southwest of the country, and its capital is Neiva. Demography and Ethnography Huila is a department that has a population of 1,122,622 inhabitants, of which 679,667 (60.54% ...

, where its fossils were discovered in sediments corresponding to the

La Victoria Formation The Honda Group ( es, Grupo Honda, Tsh, Ngh) is a geological group of the Upper and Middle Magdalena Basins and the adjacent Central and Eastern Ranges of the Colombian Andes. The group, in older literature also defined as formation, is in its ...

, belonging to the

Honda Group is a Japanese public multinational conglomerate manufacturer of automobiles, motorcycles, and power equipment, headquartered in Minato, Tokyo, Japan. Honda has been the world's largest motorcycle manufacturer since 1959, reaching a product ...

of the Middle

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

.Cifelli, R. L. and Guerrero, J. (1997). Litopterns. In: ''Vertebrate Paleontology in the Neotropics: The Miocene Fauna of La Venta, Colombia'' (R. Kay, R. H. Madden, R. L. Cifelli, and J. J. Flynn, eds.). Smithsonian Institution Press, Washington and London, 289-302.

Description

This animal is known from 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 ...

specimen IGM 250965, a partial skull lacking the anterior rostrum, although it retains the roots of the upper first

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 ...

(P1), and some additional remains, including another skull, UCMP 39970, several molar teeth, fragments of the mandible, two

cervical In anatomy, cervical is an adjective that has two meanings: # of or pertaining to any neck. # of or pertaining to the female cervix: i.e., the ''neck'' of the uterus. *Commonly used medical phrases involving the neck are **cervical collar **cervic ...

vertebrae, the right

scapula The scapula (plural scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on eithe ...

, a distal end of the

radius In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

, the proximal end of the right

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...

, the left tibia, the

calcaneus In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is the point of the hock. S ...

and several

phalange The phalanges (singular: ''phalanx'' ) are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges. The phalanges are classed as long bones. ...

s of the fingers. Its remains indicate that it was a running herbivore similar in shape and size to the southern genera ''

Proterotherium ''Proterotherium'' (meaning "first beast") is an extinct genus of litoptern mammal of the family Proterotheriidae that lived during the Late Miocene of Argentina and Chile. Fossils of this genus have been found in the Ituzaingó Formation of Arge ...

'' and ''

Anisolophus ''Anisolophus'' is an extinct genus of proterotheriid from the Early to Middle Miocene of Argentina. The genus was named by Burmeister in 1885 to accommodate the species ''Anchitherium australe'', which they had named earlier in 1879. Soria then ...

'', although it had a greater degree of molarization of its premolar teeth, especially P3 and P4. Given that its remains show a mixture of primitive and advanced features it is difficult to say whether these resemblances correspond to their actual

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

s, awaiting more comprehensive analyses of the family Proterotheriidae.

References

{{Taxonbar, from=Q6162932 Proterotheriids Prehistoric placental genera Miocene mammals of South America Neogene Colombia Fossils of Colombia Honda Group, Colombia Laventan Fossil taxa described in 1997