Chalicotheriidae is an extinct family of herbivorous, odd-toed ungulate (perissodactyl) mammals that lived in North America, Eurasia, and Africa from the Middle Eocene to the Early Pleistocene. They are often called chalicotheres, a term which is also applied to the broader grouping of Chalicotherioidea. They are noted for their unusual morphology compared to other ungulates, such as their clawed forelimbs. Members of the subfamily Chalicotheriinae developed elongate gorilla-like forelimbs that are thought to have been used to grasp vegetation. They are thought to have been browsers on foliage as well as possibly bark and fruit.
Hemicyon, also known as the "dog-bear", is an extinct genus of hemicyonine bear, which probably originated in Eurasia but was found in Europe, Asia and North America during the Miocene epoch, existing for approximately 16 to 13 mya. Hemicyon is the best-known genus in the Hemicyoninae, a subfamily intermediate between bears and their Caniform ancestors but most often classified as bears. Hemicyonid bears should not be confused with Amphicyonids (bear-dogs), which are their own separate family of carnivores.
Parahippus leonensis is an extinct proto-horse of the family Equidae that was endemic to North America during the Miocene from 23.030 to 16.3 Ma living for approximately 6.73 million years.
Pseudhipparion is an extinct genus of three-toed horse endemic to North America during the Miocene. They were herding animals whose diet consisted of C3 plants. Fossils found in Georgia and Florida indicate that it was a lightweight horse, weighing up to 90 pounds. In 2005, fossils were unearthed in Oklahoma. Seven species of Pseudhipparion are known from the fossil record which were very small, following the trend of Bergmann's rule.
Nannippus is an extinct genus of three-toed horse endemic to North America during the Miocene through Pleistocene, about 13.3—1.8 million years ago (Mya), living around 11.5 million years. This ancient species of three-toed horse grew up to 3.5 feet and weighed between 165 pounds to 199 pounds, which was around the same size as a domestic sheep.
Cormohipparion is an extinct genus of horse belonging to the tribe Hipparionini that lived in North America during the late Miocene to Pliocene. They grew up to 3 feet long.
Archaeohippus is an extinct three toed member of the family Equidae known from fossils of early Oligocene to middle Miocene age. The genus is noted for several distinct skeletal features. The skull possesses deeply pocketed fossa in a notably long preorbital region. The genus is considered an example of phyletic dwarfism with adults estimated at being on average 20 kilograms in weight. This is in contrast to the most common equid of the period, Miohippus. Characters of the teeth show a mix of both primitive and advanced traits. The advanced traits are very similar to those shown in the genus Parahippus. The noted similarities of Archaeohippus and Parahippus show them to be descended from a common ancestor. They are considered sister species.
The Torreya Formation is a Miocene geologic formation with an outcrop in North Florida. It is within the Hawthorn Group.
The Leon County paleontological sites are assemblages of Early Miocene invertebrates and vertebrates of Leon County, Florida, United States.
The Gadsden County paleontological sites are assemblages of Early Miocene invertebrates and vertebrates occurring in Gadsden County, Florida, United States.
The St. Marys Formation is a geologic formation in Maryland and Virginia, United States. It preserves fossils dating back to the Miocene Epoch of the Neogene period. It is the youngest Miocene formation present in the Calvert Cliffs and is part of the Chesapeake Group.
The Ashley Formation is a geologic formation in South Carolina. It preserves fossils dating back to the Paleogene period.
The Chandler Bridge Formation is a geologic formation in South Carolina. It preserves fossils dating back to the Chattian of the Paleogene period, corresponding to the Arikareean in the NALMA classification. The formation overlies the Ashley Formation and is overlain by the Edisto Formation.
The Parachucla Formation is a geologic formation in the southeastern United States. It preserves fossils from the Aquitanian stage of the early Miocene period. The formation is included in the Hawthorn Group. An exposure at the northern end of the formation has produced fossils estimated to be 19.4 to 20.5 Million years ago (Ma). Another exposure at the southern end of the formation has produced fossils estimated to be 23.9 to 24.7 Ma.
The Alachua Formation is a Miocene geologic formation in Florida. The claystones, sandstones and phosphorites of the formation preserve many fossils of mammals, birds, reptiles and fish, among others megalodon.
The Ash Hollow Formation of the Ogallala Group is a geological formation found in Nebraska and South Dakota. It preserves fossils dating back to the Neogene period. It was named after Ash Hollow, Nebraska and can be seen in Ash Hollow State Historical Park. Ashfall Fossil Beds State Historical Park is within this formation.
The Astoria Formation is a geologic formation in Washington state & Oregon. It preserves fossils dating back to the early to middle Miocene.
The Cucaracha Formation (Tca) is a geologic formation in Panama. It preserves vertebrate and plant fossils dating back to the Neogene period; Early to Middle Miocene epochs (Hemingfordian). Fossils of the crocodylian Centenariosuchus, the turtle Rhinoclemmys panamaensis and the artiodactyl Paratoceras have been found in the formation.
Floridachoerus olseni is an extinct peccary that lived during the Hemingfordian age of the Early Miocene, and was endemic to North America. F. olseni was in existence for approximately 4.46 million years. Remains of this extinct mammal were located at the fossil rich Thomas Farm site in Gilchrist County, Florida and Toledo Bend site, Newton County, Texas. Floridachoerus olseni was named after Stanley. J. Olsen of the Florida Geological Survey in 1962. Olsen previously worked at the site for Harvard University.
Crenatosiren is an extinct genus of dugongid sirenian known from the late Oligocene (Chattian) of Florida, North Carolina, and South Carolina. The type and only known species is Crenatosiren olseni.
