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.
Pilgrimella is an extinct early Eocene genus of anthracobunid, a group of stem perissodactyls. It was a ground dwelling grazer with massive bilophodont molars Dental remains of this animal have been found in Chorlakki, Punjab province, Pakistan, and in the Subathu Formation in North-West India.
Phenacodus is an extinct genus of mammals from the late Paleocene through middle Eocene, about 55 million years ago. It is one of the earliest and most primitive of the ungulates, typifying the family Phenacodontidae and the order Perissodactyla.
Tethytheria is a clade of mammals that includes the sirenians and proboscideans, as well as the extinct order Embrithopoda.
Chalicotherium is a genus of extinct odd-toed ungulates of the order Perissodactyla and family Chalicotheriidae. The genus is known from Europe and Asia, from the Middle Miocene to Late Miocene.
Panperissodactyla is a clade of ungulates containing living order Perissodactyla and all extinct ungulates more closely related to Perissodactyla than to Artiodactyla.
Archaeoceti, or Zeuglodontes in older literature, is a paraphyletic group of primitive cetaceans that lived from the Early Eocene to the late Oligocene. Representing the earliest cetacean radiation, they include the initial amphibious stages in cetacean evolution, thus are the ancestors of both modern cetacean suborders, Mysticeti and Odontoceti. This initial diversification occurred in the shallow waters that separated India and Asia 53 to 45 mya, resulting in some 30 species adapted to a fully oceanic life. Echolocation and filter-feeding evolved during a second radiation 36 to 35 mya.
Anthracobunidae is an extinct family of stem perissodactyls that lived in the early to middle Eocene period. They were originally considered to be a paraphyletic family of primitive proboscideans possibly ancestral to the Moeritheriidae and the desmostylians. The family has also thought to be ancestral to the Sirenia.
Anthracobune is an extinct genus of stem perissodactyl from the middle Eocene of the Upper Kuldana Formation of Kohat, Punjab, Pakistan.
Ishatherium is an extinct genus of ungulate from the early Eocene of the Subathu formation in northwestern India.
Lammidhania is an extinct genus of anthracobunids, which lived from the early to middle Eocene period. Its fossil remains were discovered in 1940 in the Chorlakki locality of the Punjab province of Pakistan.
Nakusia is an extinct genus of ungulate from the early Eocene epoch, described in 1999 in the Ghazij formation of Baluchistan, Pakistan. It was classified as an anthracobunid in 1999 but was suggested in a 2014 cladistic analysis to be more likely to belong to Quettacyonidae or Cambaytheriidae.
Meniscotherium is an extinct genus of dog-sized mammal which lived 54–38 million years ago. It was a herbivore and had hooves. Fossils have been found in Utah, New Mexico. and Colorado. Many individuals have been found together, indicating that it lived in groups.
Indobune is an extinct genus of ungulate endemic to Asia during the Eocene from 55.8—48.6 Ma, living for approximately 7.2 million years.
Afrasia djijidae is a fossil primate that lived in Myanmar approximately 37 million years ago, during the late middle Eocene. The only species in the genus Afrasia, it was a small primate, estimated to weigh around 100 grams (3.5 oz). Despite the significant geographic distance between them, Afrasia is thought to be closely related to Afrotarsius, an enigmatic fossil found in Libya and Egypt that dates to 38–39 million years ago. If this relationship is correct, it suggests that early simians dispersed from Asia to Africa during the middle Eocene and would add further support to the hypothesis that the first simians evolved in Asia, not Africa. Neither Afrasia nor Afrotarsius, which together form the family Afrotarsiidae, is considered ancestral to living simians, but they are part of a side branch or stem group known as eosimiiforms. Because they did not give rise to the stem simians that are known from the same deposits in Africa, early Asian simians are thought to have dispersed from Asia to Africa more than once prior to the late middle Eocene. Such dispersals from Asia to Africa also were seen around the same time in other mammalian groups, including hystricognathous rodents and anthracotheres.
Afrotarsius is a primate found in the Paleogene of Africa.
Indolophus is an extinct genus of perissodactyl belonging to the clade Tapiromorpha, which includes modern-day tapirs. Fossils have been found in the Early Eocene of Myanmar.
Deperetella is an extinct genus of deperetellid perissodactyls from Middle to Late Eocene of Asia. The genus was defined in 1925 by W. D. Matthew and Walter W. Granger, who named it after French paleontologist Charles Depéret. The type species is Deperetella cristata.
The Amphipithecidae were simian primates that lived in Late Eocene and Early Oligocene. Fossils have been found in Myanmar, Thailand, and Pakistan. The limited fossil evidence is consistent with, but not exclusive to, arboreal quadrupedalism. In other words, the species may have moved about in trees on four legs, but not with regular leaping as seen in later simians.
Hyainailourinae ("hyena-cats") is an extinct subfamily of hyainailourid hyaenodonts that lived in Africa, Asia, North America and Europe from the middle Eocene to middle Miocene. They appeared in Africa about 47.8 Ma ago and soon after spread as far as East Asia.
