hyracodont

fossil mammal family

Also known as: Hyracodontidae

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June 29, 2026

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The Hyracodontidae, also known as "running rhinoceroses," were a family of extinct mammals that lived during the Eocene and Oligocene epochs. These animals were primitive relatives of modern rhinoceroses.12

Key characteristics of Hyracodontidae include:
* Appearance: They had long, slender legs and were of a light, agile build.12
* Feet: All their feet had three toes.12
* Teeth: They possessed typical rhinoceros cheek teeth.1
* Horns: Unlike modern rhinoceroses, they were hornless.2

Fossils of Hyracodontidae have been found in North America and Asia. They are considered an early branch within the evolution of rhinoceroses.13

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perissodactyl
Rhinoceroses
…branch, perhaps derived from primitive hyracodonts. Metamynodon and some other forms were about as large as hippopotamuses and may have lived in rivers. The premolars were simple and the incisors reduced, but canines and molars were enlarged.
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…branch, perhaps derived from primitive hyracodonts. Metamynodon and some other forms were about as large as hippopotamuses and may have lived in rivers. The premolars were simple and the incisors reduced, but canines and molars were enlarged.
Read More