Tetrastylus

Tetrastylus is an extinct genus of dinomyid rodent that lived in South America during the Neogene and Quaternary periods.

Distribution

Tetrastylus is known from Argentina, Uruguay, Brazil, and Venezuela.

Palaeobiology

Locomotion

Analysis of the occipitocervical morphology of Tetrastylus intermedius specimens from northwestern Argentina suggests that this species was a terrestrial animal, but it still retained some holdover traits related to arborealism from its evolutionary past, such as larger paracondyles relative to the modern pacarana and a size-proportionate head. It was less scansorial, however, than the extant Dinomys.