''Protolipterna'' 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 ...

genus of

mammal 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 ...

, belonging to the order

Litopterna Litopterna (from grc, λῑτή πτέρνα "smooth heel") is an extinct order of fossil hoofed mammals from the Cenozoic era. The order is one of the five great orders of South American ungulates that were endemic to the continent, until the G ...

. It lived during the Late Paleocene and the Early Eocene, in what is now South America.

Description

It was a small-sized animal, not exceeding 35 centimeters in length ; it weighed approximately one kilogram. It had a compact body and elongated and slender legs. Its general appearance was comparable to that of a modern chevrotain. Its dentition possessed low-crowned brachyodont and bunodont molars, but it also had long upper fang-shaped

canine Canine may refer to: Zoology and anatomy * a dog-like Canid animal in the subfamily Caninae ** '' Canis'', a genus including dogs, wolves, coyotes, and jackals ** Dog, the domestic dog * Canine tooth, in mammalian oral anatomy People with the ...

s, not unlike today's chevrotains. Its legs, elongated and slender, suggest a

digitigrade In terrestrial vertebrates, digitigrade () locomotion is walking or running on the toes (from the Latin ''digitus'', 'finger', and ''gradior'', 'walk'). A digitigrade animal is one that stands or walks with its toes (metatarsals) touching the groun ...

gait, unlike its contemporaries, such as ''

Colbertia ''Colbertia'' is an extinct genus of oldfieldthomasiid notoungulate. It lived from the Early to the Middle Eocene, and its fossilized remains were discovered in Argentina and Brazil. Description This animal was roughly the size of a Virginia ...

'', which were

plantigrade 151px, Portion of a human skeleton, showing plantigrade habit In terrestrial animals, plantigrade locomotion means walking with the toes and metatarsals flat on the ground. It is one of three forms of locomotion adopted by terrestrial mammals. T ...

Classification

''Prtolitopterna ellipsodotoides'' was first described by Cifelli in 1983, based on fragmentary mandible preserving teeth, found in the Itaboraí Formation of Brazil, in terrains dated from the end of the Paleocene or the Early Eocene. Several other fossils were later found, making it possible to reconstruct its appearance and affinities. ''Protolipterna'' was a basal litoptern, a clade of mammals that diversified in South America during the

Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configura ...

. ''Protolipterna'' is the eponymous genus of Protolipternidae, a possibly paraphyletic family including some of the most basal members of Litopterna. The name ''Protolipterna'' is an anagram of Litopterna coupled with the prefix ''proto''-, "first". One of the close relatives of this genus was ''

Asmithwoodwardia ''Asmithwoodwardia'' is an extinct genus of mammals, from the order Litopterna. It lived during the Late Paleocene and the Early Eocene, and its fossilized remains were found in South America. Description Known almost only from skull material ...

''.

Paleoecology

Studies of the postcranial skeleton of ''Protolipterna'' allows to hypothesize that this animal, with its long

legs, was able to run quickly and to jump. Its bunodont molars were ideal for the consumption of tender foliage. It is unclear whether the long upper canines were a feature affecting only of the two sexes.

Bibliography

*F. Ameghino. 1901. Notices préliminaires sur des ongulés nouveaux des terrains crétacés de Patagonie reliminary notes on new ungulates from the Cretaceous terrains of Patagonia Boletin de la Academia Nacional de Ciencias de Córdoba 16:349-429 *G. G. Simpson. 1948. The beginning of the age of mammals in South America. Part I. Bulletin of the American Museum of Natural History 91:1-232 *C. d. Paula Couto. 1952. Fossil mammals from the beginning of the Cenozoic in Brazil. Condylarthra, Litopterna, Xenungulata, and Astrapotheria. Bulletin of the American Museum of Natural History 99(6):355-394 *R. Cifelli. 1985. Biostratigraphy of the Casamayoran, Early Eocene of Patagonia. American Museum Novitates 2820:1-26 *E. V. Oliveira and F. J. Goin. 2011. A reassessment of bunodont metatherians from the Paleogene of Itaborai (Brazil): Systematics and the age of the Itaborian SALMA. Revista Brasileira de Paleontologia 14(2):105-136 {{Taxonbar, from=Q42268903 Litopterns Condylarths Eocene mammals of South America Paleocene mammals of South America Paleogene Brazil Fossils of Brazil Fossil taxa described in 1983 Prehistoric placental genera Itaboraí Formation