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 more than 50 million years ago, in the Eocene epoch, 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. It is more specifically grouped within the superfamily Equoidea, the only other family being the extinct Palaeotheriidae.
A mastodon is a member of the genus Mammut, which was endemic to North America and lived from the late Miocene to the early Holocene. Mastodons belong to the order Proboscidea, the same order as elephants and mammoths. Mammut is the type genus of the extinct family Mammutidae, which diverged from the ancestors of modern elephants at least 27–25 million years ago, during the Oligocene.
Anza-Borrego Desert State Park is a California State Park located within the Colorado Desert of Southern California, United States. The park takes its name from 18th century Spanish explorer Juan Bautista de Anza and borrego, a Spanish word for sheep. With 585,930 acres (237,120 ha) that includes one-fifth of San Diego County, it is the largest state park in California and the third largest state park nationally.
Equus is a genus of mammals in the family Equidae, which includes horses, asses, and zebras. Within the Equidae, Equus is the only recognized extant genus, comprising seven living species. Like Equidae more broadly, Equus has numerous extinct species known only from fossils. The genus originated in North America and dispersed into the Old World and South America during the Early and Middle Pleistocene. Equines are odd-toed ungulates with slender legs, long heads, relatively long necks, manes, and long tails. All species are herbivorous, and mostly grazers, with simpler digestive systems than ruminants but able to subsist on lower-quality vegetation.
Miracinonyx is an extinct genus of felids belonging to the subfamily Felinae that was endemic to North America from the Pleistocene epoch and morphologically similar to the modern cheetah, although its apparent similar ecological niches have been considered questionable due to anatomical morphologies of the former that would have limited the ability to act as a specialized pursuit predator. The genus was originally known from fragments of skeletons, but nearly complete skeletons have been recovered from Natural Trap Cave in northern Wyoming.
Aiolornis incredibilis is an extinct species of teratorn bird from the western United States. Only fragmentary remains have been found, which are dated between the Early Pliocene (Zanclean) and Late Pleistocene. First described as Teratornis incredibilis by Howard in 1952 based on a cuneiform bone, the species has been moved to the new genus Aiolornis by Campbell, Scott and Springer in 1999. The generic name is derived from the ancient Greek words aiolus and ornis. Aiolus refers to the Greek god of the wind, and ornis means "bird". The specific name incredibilis means 'incredible'. A. incredibilis is lesser-known than its close relative, Teratornis merriami, even though A. incredibilis was significantly larger. It presumably became extinct at the same time as the other megafauna in North America.
The wild horse is a species of the genus Equus, which includes as subspecies the modern domesticated horse as well as the endangered Przewalski's horse. The European wild horse, also known as the tarpan, that went extinct in the late 19th or early 20th century has previously been treated as the nominate subspecies of wild horse, Equus ferus ferus, but more recent studies have cast doubt on whether tarpans were truly wild or if they actually were feral horses or hybrids.
Equus lambei, commonly known as the Yukon horse or Yukon wild horse, is an extinct species of the genus Equus. Equus lambei ranged across North America until approximately 10,000 years ago. Based on recent examinations of the mtDNA of Equus lambei remains, scientists have concluded that E. lambei was probably much like the extinct tarpan, also known as the Eurasian wild horse, and the living Przewalski's horse. A partial carcass of Equus lambei is on display at the Yukon Beringia Interpretive Centre in Whitehorse, Yukon.
Titanis is a genus of phorusrhacid, an extinct family of large, predatory birds, in the order Cariamiformes that inhabited the United States during the Pliocene and earliest Pleistocene. The first fossils were unearthed by amateur archaeologists Benjamin Waller and Robert Allen from the Santa Fe River in Florida and were named Titanis walleri by ornithologist Pierce Brodkorb in 1963, the species name honoring Waller. The holotype material is fragmentary, consisting of only an incomplete right tarsometatarsus and phalanx, but comes from one of the largest phorusrhacid individuals known. In the years following the description, many more isolated elements have been unearthed from sites from other areas of Florida, Texas, and California. The species was classified in the subfamily Phorusrhacinae, which includes some of the last and largest phorusrhacids like Devincenzia and Kelenken.
Charles Whitney Gilmore was an American paleontologist who gained renown in the early 20th century for his work on vertebrate fossils during his career at the United States National Museum. Gilmore named many dinosaurs in North America and Mongolia, including the Cretaceous sauropod Alamosaurus, Alectrosaurus, Archaeornithomimus, Bactrosaurus, Brachyceratops, Chirostenotes, Mongolosaurus, Parrosaurus, Pinacosaurus, Styracosaurus ovatus and Thescelosaurus.
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.
Equus simplicidens, also known as the Hagerman horse 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. It is the state fossil of Idaho, where abundant remains of the species were discovered near the town of Hagerman in 1928.
Equus alaskae was a Pleistocene species of horse, now extinct, that inhabited North America.
Equus semplicatus was a Pleistocene species of New World stilt-legged horse, and considered the type species for the stilt legged horses, one of three lineages of equids within the Americas, the other two being hippidionid and caballine horses. Now extinct, Equus semiplicatus once inhabited North America.
James Williams Gidley (1866-1931) was an American paleontologist and museum curator.
Equus occidentalis is an extinct species of wild horse that once inhabited North America, specifically the Southwestern United States, during the Pleistocene epoch. It was first described from three teeth with insufficient diagnostic characters, one even being suggested to be a separate taxon related to the American Zebra, leading some researchers to consider it a nomen dubium, though this taxonomic debate is yet to be fully resolved.
The Palm Spring Formation is a Pleistocene Epoch geologic formation in the eastern Colorado Desert of Imperial County and San Diego County County, Southern California.
The Ocotillo Formation is a Pliocene fluvial-alluvial fan geologic formation in the Colorado Desert of Southern California.
The giant horse is an extinct species of horse which lived in North America.
Equus niobrarensis is an extinct species of Equus, the genus that includes the horse. E. niobrarensis may be synonymous with Equus scotti. It was "stout-legged" and belonged to the "big horses" category as defined by M. C. Winans. The skull of the horse was noted as being broader than Equus caballus.
