Penetrigonias ( Latin Penetrigonias , comes from " Pene , paene " - "almost", and trigonias ; "almost trigonias ") - a genus of extinct small and primitive hornless rhinos that lived in North America in the late Eocene - Early Oligocene . Two types of penetrigonias are known.
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| Penetrigonias Tanner et Martin, 1976 |
Content
- 1 Appearance and structure
- 2 Places and antiquities of finds
- 3 Lifestyle and nutrition
- 4 Views
- 5 Links
Appearance and structure
They were medium-sized slender animals with a body weight of 50-200 kg and a skull length of not more than 30 cm. They differed from teletaceras not only in larger sizes, but also in a number of progressive morphological features: their premaxilla was greatly reduced; incisors had a structure typical for rhinos; a third pair of incisors and lower fangs are lost; the second incisors are chisel-shaped and larger than the upper canines; there were progressive features in the structure of the humerus and lower jaw.
Places and antiquities of finds
It is now known that the Penetrigonias lived from the Late Eocene to the Early Oligocene; their meager fossils were found in the USA ( Wyoming , Nebraska ) and Canada ( Saskatchewan ).
Lifestyle & Nutrition
Penetrigonias could feed on the foliage of shrubs and lower branches of trees. Apparently, they were quite mobile animals that lived in half-open and open spaces, like hyracodontids . They could form small herds.
Views
- Penetrigonias hudsoni Hanson, 1920 (synonyms: Caenopus dakotensis ,? P. hudsoni ) - type species, fossils found in the USA (Nebraska, Wyoming, Montana , Colorado , South Dakota ). They date from the late Eocene - the early Oligocene. It was the largest species of its kind (body weight up to 200 kg).
- Penetrigonias sagittatus Russell, 1982 - a smaller and more ancient species. Found in deposits of the late Eocene of Canada (Saskatchewan).