Equidae is the taxonomic family of horses and related animals, including the extant horses, asses, and zebras, and many other species known only from fossils. The family evolved around 50 million years ago from a small, multi-toed ungulate into larger, single-toed animals. All extant species are in the genus Equus, which originated in North America. Equidae belongs to the order Perissodactyla, which includes the extant tapirs and rhinoceros, and several extinct families.
Diceros is a genus of rhinoceros containing the extant black rhinoceros (Diceros bicornis) and several extinct species.
Ceratotherium is a genus of the family Rhinocerotidae, consisting of a single extant species, the white rhinoceros, and its extinct relative Ceratotherium mauritanicum, of which Ceratotherium efficax is considered a synonym. Another species known as Ceratotherium praecox is now considered a member of the related genus Diceros. The placement of Ceratotherium neumayri from the Late Miocene of Europe and Western Asia within the genus has been questioned, with other authors assigning it to the separate genus Miodiceros. The species 'Ceratotherium’ advenientis is known from the Late Miocene of Italy.
Hadar or Hadar Formation is a paleontological fossil site located in Mille district, Administrative Zone 1 of the Afar Region, Ethiopia, 15 km upstream (west) of the A1 road's bridge across the Awash River.
Chalicotheriidae is an extinct family of herbivorous, odd-toed ungulate (perissodactyl) mammals that lived in North America, Eurasia, and Africa from the Middle Eocene until the Early Pleistocene, existing from 48.6 to 1.806 mya. 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 elongated clawed forelimbs. They are thought to have been browsers.
Hippidion is an extinct genus of equine that lived in South America from the Late Pliocene to the end of the Late Pleistocene (Lujanian), between 2.5 million and 11,000 years ago. They were one of two lineages of equines native to South America during the Pleistocene epoch, alongside Equus (Amerhippus) neogeus.
Palaeotheriidae is an extinct family of herbivorous perissodactyl mammals that inhabited Europe, with less abundant remains also known from Asia, from the mid-Eocene to the early Oligocene. They are classified in Equoidea, along with the living family Equidae.
Equus simplicidens, sometimes known as the Hagerman horse or the American Zebra is an extinct species of equine native to North America during the Pliocene and Early Pleistocene. It is one of the oldest and most primitive members of the genus Equus. Abundant remains of it were discovered in 1928 in Hagerman, Idaho. It is the state fossil of Idaho.
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 20kg 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 and are considered sister species.
Ceratotherium mauritanicum is a species of fossil African rhinoceros found in the Late Pliocene to early Late Pleistocene of Morocco, Tunisia, and Algeria. It is disputed as to whether remains from the Pliocene of East Africa belong to this species, and if so, whether C. mauritanicum is ancestral to the modern white rhinoceros. During the early Late Pleistocene, sometime between 120-57,000 years ago, it was replaced in North Africa by the modern white rhinoceros.
The Shungura Formation is a stratigraphic formation located in the Omo river basin in Ethiopia. It dates to the Late Pliocene to Early Pleistocene. Oldowan tools have been found in the formation, suggesting early use of stone tools by hominins. Among many others, fossils of Panthera were found in Member G of the formation.
This paleomammalogy list records new fossil mammal taxa that were described during the year 2013, as well as notes other significant paleomammalogy discoveries and events which occurred during that year.
Eurygnathohippus woldegabrieli is an extinct species of prehistoric horse. The 4.4 to 4.2 million-year-old fossils of its teeth and bones were found in 2001 and 2002 in Ethiopia. It was identified as a new species in 2013 by researchers at Case Western Reserve University, and the species named after geologist and Case Western alumnus Giday WoldeGabriel.
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.
Calippus is an extinct genus of hoofed mammals in the horse family (Equidae), known from the Middle Miocene through the Early Pliocene of North and Central America. Fossils have been found in the Central United States and the Eastern United States, ranging south to Honduras. These equines had high crowned teeth and a quadrangular, wide muzzle, and were small compared to their contemporary relatives, with C. elachistus weighing 49 kg, C. cerasinus weighing 102 kg, 132 kg for C. theristes and 73 kg for C. mccartyi.
