U is for Uintatherium
Uintatherium was a massive hoofed mammal that lived during the Eocene epoch. Superficially, they were rather rhinoceros-like, though they were not related.
A reconstruction of Uintatherium.
Credit: Dmitry Bogdanov CC 3.0 By SA
Notably, Uintatheres had many horns and protuberances on their skulls, in addition to robust tusks.
Cast of Uintatherium anceps (Leidy, 1872) – syn. Dinoceras mirabile (Marsh 1872) skull, neck vertebrae.
Credit: Jebulon [Public Domain]
T is for Tapocyon
Tapocyon is a genus of miacid carnivores that lived during the Paleocene and Eocene epochs of North America. It was a climbing mammal that likely spent a great amount of time in trees.
Life reconstruction of Tapocyon robustus.
Credit: Nobu Tamura CC 4.0 By SA
S is for Smilodectes
Smilodectes is an extinct primate that lived in North America during the Eocene.
Early Eocene (55-50 mya); Smilodectes gracilis, Smithsonian National Museum of Natural History.
Credit: Ryan Somma CC 2.0 By-SA
R is for Reithroparamys
Reithroparamys is another extinct rodent from North America. Species of this genus ranged from the late Paleocene into the mid-Eocene. Four species are known from this genus.
Q is for Quadratomus
Quadratomus is an Eocene rodent. There are four species within this genus all of which lived in North America.
P is for Protylopus
Protylopus is an extinct type of camel that lived from the middle to late Eocene in North America. It is the oldest known camel.
Protylopus petersoni skull.
Credit: Robert Bruce Horsfall [Public domain], via Wikimedia Commons
O is for Ourayia
Ourayia is a fossil primate, which, like Notoparamys, is related to tarsiers. Like many fossil mammals, it is best known for its teeth.
VPPU.011236: Ourayia uintensis: HYPODIGM. Utah. Uintah County. Kennedy’s Hole, Uinta Basin. Princeton 1895 Hatcher Expedition. Coll: Hatcher, J. B. 25 Mar 1895. Tertiary. Late Eocene. Uintan. Uinta Fm. Middle Uinta B.
Courtesy of the Peabody Museum of Natural History,
Division of Vertebrate Paleontology, Yale University; peabody.yale.edu
N is for Notoparamys
Notoparamys was a marmot-sized rodent that lived in the earliest Uintan. It is a member of the rodent group Ischyromyidae, which included some arboreal (climbing) rodents.
M is for Macrotarsius
Macrotarsius is a fossil primate closely related to and similar in appearance to modern tarsiers.
Philippine Tarsier (Carlito syrichta), one of the smallest primates. This one is about 5 inches long with a tail longer than its body. Photo taken in Bohol, Philippines. Credit: mtoz CC 2.0 By SA
Modern tarsiers are unique in the structure of their back foot, specifically the ankle bones (the tarsals), hence their common name of ‘tarsier.’
L is for Leptotragulus
Leptotragulus was a hoofed mammal that would have roughly looked like a deer, but were more closely related to camels and llamas. They were a member of a group called the Protoceratidae, that were unique in having horns on their snouts.
Here is a relative of Leptotragulus, Synthetoceras:
Synthetoceras tricornatus. Credit: Nobu Tamura CC 3.0 By