''Typotheriopsis'' is an

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 ...

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 ...

Notoungulate Notoungulata is an extinct order of ungulates that inhabited South America from the early Paleocene to the end of the Pleistocene, living from approximately 61 million to 11,000 years ago. Notoungulates were morphologically diverse, with forms re ...

belonging to the family

Mesotheriidae Mesotheriidae ("Middle Beasts") is an extinct family of notoungulate mammals known from the Oligocene through the Pleistocene of South America. Mesotheriids were small to medium-sized herbivorous mammals adapted for digging. Characteristics Mes ...

, which included several small Meridiungulates specialized in digging. It is considered as the

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

of the clade including ''

Mesotherium ''Mesotherium'' ("middle beast") is an extinct genus of mesotheriid, a long-lasting family of superficially rodent-like, burrowing notoungulates from South America. It is one of the youngest notoungulates, spanning the Early-Middle Pleistocene ...

'' and '' Pseudotypotherium''. Its

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

are known from the

Chasicoan The Chasicoan ( or ) age is a period of geologic time from 10–9 Ma within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Mayoan and precedes the Huayquerian age.

and the

Huayquerian The Huayquerian () age is a period of geologic time (9.0–6.8 Ma) within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification. It follows the Chasicoan and precedes the Montehermosan age. Etymology T ...

periods, notably among

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...

rocks from the

Arroyo Chasicó Formation Arroyo often refers to: * Arroyo (watercourse), an intermittently dry creek Arroyo may also refer to: Places United States * Arroyo, Pennsylvania * Arroyo, Puerto Rico, a municipality * Arroyo, West Virginia Spain * Arroyo (Santillana del Mar), ...

and the

Cerro Azul Formation The Cerro Azul Formation (), also described as Epecuén Formation, is a formation (geology), geological formation of Late Miocene (Tortonian, or Huayquerian in the South American land mammal age, SALMA classification) age in the Colorado Basin, Arg ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

Description

''Typotheriopsis chasicoensis'' was described in 1931 by Angel Cabrera and Jorge L. Kraglievich, with a holotype composed of badly preserved cranial remains from the Arroyo Chasicó Formation of

. Those remains were similar to ''Pseudotypotherium'', but included thicker enamel and less rudimentary

incisors Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, wher ...

than in other genera of mesotherid. Later studies expanded this list of differences between ''Typotheriopsis'' and ''Pseudotypotherium''. It was large for a mesothere, with a wide skull, and a suborbital fossa on its eye socket which may have hosted a

scent gland Scent gland are exocrine glands found in most mammals. They produce semi-viscous secretions which contain pheromones and other semiochemical compounds. These odor-messengers indicate information such as status, territorial marking, mood, and se ...

References

Typotheres Prehistoric placental genera Miocene mammals of South America Chasicoan Fossils of Argentina Fossil taxa described in 1931 Cerro Azul Formation Neogene Argentina {{notoungulate-stub