Hegetotheriidae

Hegetotheriidae Temporal range: Late Oligocene–Early Pleistocene PreꞒ Ꞓ O S D C P T J K Pg N
Prosotherium garzoni (=Propachyrucos ameghinorum).
Life restoration of Hegetotherium
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	† Notoungulata
Suborder:	† Typotheria
Family:	† Hegetotheriidae Ameghino, 1894
Subfamilies and genera
†Hegetotheriinae † Ethegotherium † Hegetotherium † Hemihegetotherium † Prohegetotherium † Pseudohegetotherium †Pachyrukhinae † Medistylus † Propachyrucos † Prosotherium Pachyrukhini † Pachyrukhos † Paedotherium † Tremacyllus

Hegetotheriidae is an extinct family of notoungulate mammals known from the Oligocene through the Pliocene of South America. ^{[1] [2]} The family underwent many sequential radiation events throughout the Cenozoic, which led to Hegetotheriids being among the most diverse of the Typotheria. ^[3]

Description

Foot structure of Hegetotherium

Skeleton of Pachyrukhos

Hegetotheriids are anatomically convergent with caviomorph rodents, possessing hypertrophied (enlarged) incisors. The incisors of Hegetotheriids are also hypsodont, scalpriform and procumbent, indicating a diet of abrasive plants. This is due to the fact that Hegetotheriids, living in the southernmost portions of South America, had a diet consisting of both Neotropical and Andean flora. ^[3]

Classification

Hegetotheriidae is placed in Typotheria, a clade of rodent-like notoungulates. Historically, there has been debate as to whether Hegetotheriidae should be split from the other Typotheres, ^[4] though this view is not upheld. ^[3]

References

1. McKenna, Malcolm C., and Bell, Susan K. 1997. Classification of Mammals Above the Species Level. Columbia University Press, New York, 631 pp. ISBN   0-231-11013-8
2. "Fossilworks: Hegetotheriidae". fossilworks.org. Archived from the original on 13 December 2021. Retrieved 17 December 2021.
3. Phylogeny and paleobiogeography of Hegetotheriidae (Mammalia, Notoungulata), Taylor & Francis, 2017-04-07, doi:10.6084/m9.figshare.4743550.v1 , retrieved 2025-09-05
4. Ameghino, Florentino (1889). Contribucion al conocimiento de los mamiferos fosiles de la República Argentina: Obra escrita bajo los auspicios de la Academia nacional de ciencias de la República Argentina para ser presentada á la Exposicion universal de Paris de 1889 (in Spanish). P. E. Coni é hijos.