Perissodactyla is an order of ungulates. The order includes about 17 living species divided into three families: Equidae, Rhinocerotidae (rhinoceroses), and Tapiridae (tapirs). They typically have reduced the weight-bearing toes to three or one of the five original toes, though tapirs retain four toes on their front feet. The nonweight-bearing toes are either present, absent, vestigial, or positioned posteriorly. By contrast, artiodactyls bear most of their weight equally on four or two of the five toes: their third and fourth toes. Another difference between the two is that perissodactyls digest plant cellulose in their intestines, rather than in one or more stomach chambers as artiodactyls, with the exception of Suina, do.
Embolotherium is an extinct genus of brontothere that lived in Mongolia during the late Eocene epoch. It is most easily recognized by a large bony protuberance emanating from the anterior (front) of the skull. This resembles a battering ram, hence the name Embolotherium. The animal is known from about 12 skulls, several jaws, and a variety of other skeletal elements from the Ulan Gochu formation of Inner Mongolia as well as the Ergilin Dzo Formation of Outer Mongolia.
Andrewsarchus, meaning "Andrews' ruler", is an extinct genus of artiodactyl that lived during the Middle Eocene in what is now China. The genus was first described by Henry Fairfield Osborn in 1924 with the type species A. mongoliensis based on a largely complete cranium. A second species, A. crassum, was described in 1977 based on teeth. A mandible, formerly described as Paratriisodon, does probably belong to Andrewsarchus as well. The genus has been historically placed in the families Mesonychidae or Arctocyonidae, or was considered to be a close relative of whales. It is now regarded as the sole member of its own family, Andrewsarchidae, and may have been related to entelodonts. Fossils of Andrewsarchus have been recovered from the Middle Eocene Irdin Manha, Lushi, and Dongjun Formations of Inner Mongolia, each dated to the Irdinmanhan Asian land mammal age.
Uintatherium is an extinct genus of herbivorous dinoceratan mammal that lived during the Eocene epoch. Two species are currently recognized: U. anceps from the United States during the Early to Middle Eocene and U. insperatus of Middle to Late Eocene China.
Anasazisaurus is a genus of saurolophine hadrosaurid ("duckbill") ornithopod dinosaur that lived about 74 million years ago, in the Late Cretaceous Period. It was found in the Farmington Member of the Kirtland Formation, in the San Juan Basin of New Mexico, United States. Only a partial skull has been found to date. It was first described as a specimen of Kritosaurus by Jack Horner, and has been intertwined with Kritosaurus since its description. It is known for its short nasal crest, which stuck out above and between its eyes for a short distance.
Naashoibitosaurus is a genus of hadrosaurid dinosaur that lived about 73 million years ago, in the Late Cretaceous, and was found in the Kirtland Formation of the San Juan Basin in New Mexico, United States. Only a partial skeleton has been found to date. It was first described as a specimen of Kritosaurus by Jack Horner, and has been intertwined with Kritosaurus since its description.
Diplocaulus is an extinct genus of lepospondyl amphibians which lived from the Late Carboniferous to the Late Permian of North America and Africa. Diplocaulus is by far the largest and best-known of the lepospondyls, characterized by a distinctive boomerang-shaped skull. Remains attributed to Diplocaulus have been found from the Late Permian of Morocco and represent the youngest-known occurrence of a lepospondyl.
Megacerops is an extinct genus of the prehistoric odd-toed ungulate family Brontotheriidae, an extinct group of rhinoceros-like browsers related to horses. It was endemic to North America during the Late Eocene epoch, existing for approximately 4.1 million years.
Palaeosyops is a genus of small brontothere which lived during the early to middle Eocene.
Curry's bat is a species of vesper bat in the family Vespertilionidae. It is found in Cameroon and Democratic Republic of the Congo. Its natural habitats are subtropical and tropical moist lowland forests and subtropical and tropical swamps.
Smith's red rockhare, Smith's red rock hare or Smith's red rock rabbit is a species of mammal in the family Leporidae, and is the smallest member of the genus Pronolagus. The upperparts and gular collar are reddish brown in colour. It has warm, brown, grizzled, thicker hairs at the back of the body, and white to tawny, thinner underfur. It is native to Africa, found in parts of Kenya, Lesotho, Malawi, Namibia, South Africa, Tanzania, Zambia and Zimbabwe. It is a folivore, and usually forages on grasses, shrubs and herbs. It breeds from September to February, and the female litters one or two offspring. The young leave the nest at three years of age. In 1996, it was rated as a species of least concern on the IUCN Red List of Endangered Species.
Brachydiastematherium transylvanicum is the westernmost species of brontothere, with the first fossils of it being found in Transylvania, Romania. In comparison with other brontothere fossils, it is suggested that B. transylvanicum would have had an elongated head, not unlike Dolichorhinus, and be about 2 meters at the withers.
Subhyracodon is an extinct genus of hornless rhinocerotids. With a length of 2.4 m and an estimated weight of 381 kg (840 lb) in S. mitis, it was a tapir-sized herbivore on the plains of early Oligocene South Dakota 33 million years ago. It coexisted with other perissodactyls such as horses, brontotheres, and chalicotheres. Subhyracodon had no horns, relying more on its speed to escape from predators, but a species found at Wind Cave National Park had a pair of bony nasal ridges. The genus Caenopus and species originally referred to as Aceratherium were synonymized into Subhyracodon. It has been suggested to be one of the oldest known members of the subfamily Elasmotheriinae by some studies, though other studies place it firmly outside the Rhinocerotinae-Elasmotheriinae split.
Rhinotitan is an extinct genus of brontothere from the Eocene of Mongolia, where three species were described from the Shara Murun formation. The genus included medium to large brontotheres which had long skulls with nasal horns. Like other solid-horned brontotheres, Rhinotitan was sexually dimorphic in horn size. In living mammals, this pattern is found in species that live in groups; males have the larger horns, and use them in ritualized combats with other males to decide control of territories that offer breeding access to females. Most horned brontotheres had dish-shaped skulls assumed to be adapted for such combats. However, the skull of Rhinotitan was concave only near the front; the top and back of the skull was rounded in a way similar to hornless brontotheres. The functional significance of this character is unknown.
Protitanotherium is a genus of brontotheres native to North America and Korea. They lived during the Middle to Late Eocene 46.2—33.9 mya, existing for approximately 12 million years.
Brontotheriidae is a family of extinct mammals belonging to the order Perissodactyla, the order that includes horses, rhinoceroses, and tapirs. Superficially, they looked rather like rhinos with some developing bony nose horns, and were some of the earliest mammals to have evolved large body sizes of several tonnes. They lived around 56–34 million years ago, until the very close of the Eocene. Brontotheres had a Holarctic distribution, with the exception of Western Europe: they occupied North America, Asia, and Eastern Europe. They were the first fossilized mammals to be discovered west of the Mississippi, and were first discovered in South Dakota.
Diplacodon is a genus of prehistoric odd-toed ungulates in the family Brontotheriidae. It was the size of a rhinoceros, with the last two upper premolars molar-like.
Eutreptornis is a genus of extinct possible cariamiforme bird from the Late Eocene of Utah. It is traditionally considered to be a bathornithid, though a combination of the relative incompleteness of the material alongside some differences from other bathornithids have raised some suspicions about this affiliation.
Percy Milton Butler was a British zoologist and palaeontologist. He proposed that dental characters are expressed in morphogenetic gradients along the dentition, which could therefore be used to study evolution. This became known as Butler's Field Theory. He was Professor of Zoology at Royal Holloway, University of London, where he was the Head of the Department of Zoology from 1956 to 1972, and where he established the first course on mammalogy in the UK.
Nanotitanops is an extinct genus of Brontothere from the middle Eocene of China. It contains a single species, N. shanghuangensis. It is known only from isolated teeth, the smallest of any known Brontothere.
