Toxodonta

Taxobox
name = Toxodonta

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image_width = 240px
image_caption = "Toxodon"
regnum = Animalia
phylum = Chordata
classis = Mammalia
ordo = †Notoungulata
subordo = †Toxodonta
subdivision_ranks = Families
subdivision = †Homalodotheriidae
†Isotemnidae
†Leontiniidae
†Notohippidae
†Toxodontidae

Toxodonta is a suborder of the extinct mammalian order Notoungulata. The group is named after "Toxodon", the first example of the group to be discovered. The suborder includes the largest known notoungulates, members of the family Toxodontidae. Toxodontids first appeared during the Oligocene in the form of "Proadinotherium". Another well-known toxodontid is "Nesodon", a medium-sized Miocene toxodontid descended from "Proadinotherium" which had converted its second upper incisors into tusks. "Toxodon" itself evolved during the Pliocene alongside the related "Trigodon", an equally large mammal which possessed a horn projecting from its forehead, in the same way as a modern rhinoceros. "Toxodon" was a huge herbivore (about the size of a modern black rhinoceros) with four toes on each hoof.

Closely related to the toxodontids are two additional families: the Leontiniidae of the Eocene through Miocene and the Notohippidae. The last surviving notohippid was "Colpodon" from the late Oligocene, which was medium-sized but heavily built. Notohippids possessed molars that were superficially like those of modern horses.