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
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 ...
notoungulate
Notoungulata is an extinct order of mammalian ungulates that inhabited South America from the early Paleocene to the Holocene, living from approximately 61 million to 11,000 years ago. Notoungulates were morphologically diverse, with forms resemb ...
that lived during the Middle
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...
of what is now
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
. Fossils of this genus have been found in the
Sarmiento Formation
The Sarmiento Formation (Spanish: ''Formación Sarmiento''), in older literature described as the Casamayor Formation, is a geological formation in Chubut Province, Argentina, in central Patagonia, which spans around 30 million years from the mid- ...
of Argentina.
Description
This animal was similar to a medium-sized
rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...
, with a rather massive, short and compact skull. It shared several similarities with its better known relative '' Archaeopithecus'', such as nearly high-crowned (hypsodont) premolars and molars, contrary to most of the other Early Eocene notoungulates. A characteristic anatomical feature of ''Teratopithecus'' is the existence of a stylar cusp in labial position compared to the molar ectoloph, a unique condition within Notounugulata. This most likely indicates a particular specialization in nutrition.
Classification
''Teratopithecus elpidophoros'', the only known species from the genus, was first described in 2020, based on fossil remains discovered near the localities Paso del Sapo, Las Violetas and Cañadón Vaca in central
Patagonia
Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and gl ...
.
''Teratopithecus'' was an archaic member of the suborder
Typotheria
Typotheria is a suborder of the extinct mammalian order Notoungulata
Notoungulata is an extinct order of mammalian ungulates that inhabited South America from the early Paleocene to the Holocene, living from approximately 61 million to 11,0 ...
, a clade of notoungulates similar to modern
hyrax
Hyraxes (), also called dassies, are small, thickset, herbivorous mammals in the order Hyracoidea. Hyraxes are well-furred, rotund animals with short tails. Typically, they measure between long and weigh between . They are superficially simil ...
es or
rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...
s. ''Teratopithecus'' was related to '' Archaeopithecus'', a slightly younger genus, both being the only known members of the family
Archaeopithecidae
Archaeopithecidae is an extinct family comprising two genera of notoungulate mammals, '' Teratopithecus'' and '' Archaeopithecus'', both known from the Eocene of Argentina.high-crowned molars.