| Equus altidens Temporal range: | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Perissodactyla |
| Family: | Equidae |
| Genus: | Equus |
| Species: | †E. altidens |
| Binomial name | |
| †Equus altidens Von Reichenau, 1915 | |
Equus altidens is an extinct species of equine native to western Eurasia including Europe during the Early Pleistocene to early Middle Pleistocene.
Equus altidens was first described in 1915 from remains at the early Middle Pleistocene Sussenborn locality in Germany. [1] Most recent authors consider the species Equus marxi also known from Sussenborn to be a junior synonym of E. altidens. The majority of authors have suggested the species is related to other "stenonine" equines known from Early Pleistocene of Europe such as Equus stenonis, [2] which are thought to be more closely related to living zebras and asses than to true horses. Some authors have suggested a closer relationship to asses than to zebras for E. altidens. [3] Some authors have placed the species in the subgenus Sussemionus, or place it with other "stenonines" in the separate genus Allohippus. [2]
"Orce Man", a supposed archaic human fossil from the Early Pleistocene of Spain, was later determined to actually be the skull remains of a juvenile of this species. [4]
Equus altidens is a medium-sized equine species [2] with an estimated body mass of around 338–374 kilograms (745–825 lb). [5] ST2 The species had slender limbs, the most slender among the "stenonines", including the metapodial bones, and is distinguished from other equines by a number of dental morphological features, including narrow and small crowns, and deep molar ectoflexid, though the dental morphology exhibits considerable variability in a number of characters. [2]
Equus altidens is known from remains found across Europe, Spanning from the Iberian Peninsula to Italy and Greece, northwards to Germany and Britain, and as far eastwards as Georgia in the Caucasus. [2] Other possible records are known from Romania, Turkey, Tajikistan, Hungary, and Russia. [6] Authors have differed about the timing of the earliest appearance of the species, ranging from as late as 1.2 million years ago to as early as 1.8 million years ago, [2] with recent research supporting the earlier end of the range, with the earliest records coming from the Dmanisi site in Georgia. [3] The youngest remains of the species date to around 600,000 years ago, [2] when the species like other European "stenonine" equines was replaced by early caballine true horses belonging to the species Equus mosbachensis . [5]
Dental wear analysis that Equus altidens had an abraisive, largely grazing based diet, [2] [5] though it may have seasonally engaged in mixed feeding. [2] It often co-occurred alongside another larger "stenonine" equine, Equus suessenbornensis. Evidence suggests that this species had a diet that consisted of considerably more browse than E. altidens, suggesting dietary niche partitioning between the two species. [5] Equus altidens is thought to have primarily inhabited arid, open habitats. [3] Isotopic analysis from the Venta Micena locality in southeast Spain dating to the Early Pleistocene, around 1.6 million years ago, suggests that at this locality Equus altidens was regularly preyed upon by sabertooth cats, including the lion sized Homotherium , and the smaller, jaguar sized Megantereon . [7]
At the Fuente Nueva-3 site in Spain, during the late Early Pleistocene around 1.2 million years ago, cut marks found on bones indicate butchery of Equus altidens by archaic humans, [8] likely Homo antecessor . [9]
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. It is more specifically grouped within the superfamily Equoidea, the only other family being the extinct Palaeotheriidae.
The onager (Equus hemionus), also known as hemione or Asiatic wild ass, is a species of the family Equidae native to Asia. A member of the subgenus Asinus, the onager was described and given its binomial name by German zoologist Peter Simon Pallas in 1775. Six subspecies have been recognized, two of which are extinct.
Megantereon is an extinct genus of prehistoric machairodontine saber-toothed cat that lived in North America, Eurasia, and Africa from the late Pliocene to the Middle Pleistocene. It is a member of the tribe Smilodontini, and closely related to and possibly the ancestor of the famous American sabertooth Smilodon. In comparison to Smilodon it was somewhat smaller, around the size of a jaguar, though it is thought to have had a similar hunting strategy as an ambush predator.
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.
The European wild ass or hydruntine is an extinct equine from the Middle Pleistocene to Late Holocene of Europe and West Asia, and possibly North Africa. It is a member of the subgenus Asinus, and closely related to the living Asiatic wild ass. The specific epithet, hydruntinus, means from Otranto.
Mammuthus meridionalis, sometimes called the southern mammoth, is an extinct species of mammoth native to Eurasia, including Europe, during the Early Pleistocene, living from around 2.5 million years ago to 800,000 years ago.
Equus sivalensis is an extinct species of large equid native to the northern Indian subcontinent. Remains date from the beginning of the Pleistocene, c. 2.58 million years ago until around 600,000 years ago, during the Middle Pleistocene. It is considered a "stenonine horse", meaning that it is more closely related to zebras and asses than true horses. Based on isotopes and teeth morphology, it is thought to have been a grazer. The later species Equus namadicus from the same region has sometimes been suggested to be a synonym due to their similar teeth morphology.
Equus namadicus is a prehistoric equid, known from remains dating to the Middle and Late Pleistocene from across the Indian subcontinent, with its last dated records being approximately 29-14,000 years ago. It is considered a "stenonine horse", meaning that it is probably more closely related to zebras and asses than true horses. It is relatively large in size. It is very similar to the earlier Equus sivalensis, also from the Indian subcontinent, from which it only differs in size and in subtle aspects of dental anatomy, and it has sometimes been suggested to be a synonym of it.
The evolution of the horse, a mammal of the family Equidae, occurred over a geologic time scale of 50 million years, transforming the small, dog-sized, forest-dwelling Eohippus into the modern horse. Paleozoologists have been able to piece together a more complete outline of the evolutionary lineage of the modern horse than of any other animal. Much of this evolution took place in North America, where horses originated but became extinct about 10,000 years ago, before being reintroduced in the 15th century.
Equus simplicidens, sometimes known as the Hagerman horse or the American zebra is an extinct species in the horse family 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 its abundant remains were discovered in 1928, specifically in Hagerman, Idaho. They are also known from other US states including Arizona, California, Texas, Nebraska and Kansas.
Megahippus is an extinct genus of large Anchitheriine horses found throughout the southern portion of the United States during the middle Miocene. The animal represents one of the latest low-crowned horses, overlapping in time with more derived high-crowned horses.
Haringtonhippus is an extinct genus of equine from the Pleistocene of North America The genus is monospecific, consisting of the species H. francisci, initially described in 1915 by Oliver Perry Hay as Equus francisci. Members of the genus are often referred to as stilt-legged horses, in reference to their slender distal limb bones, in contrast with those of contemporary "stout legged" caballine true horses.
The Yunnan horse is an extinct species of equine that was present in East Asia during the Pleistocene very likely as a grazer on open tracts of grassland. It was a small equine comparable in size to the modern Przewalski's horse.
Equinae is a subfamily of the family Equidae, known from the Hemingfordian stage of the Early Miocene onwards. They originated in North America, before dispersing to every continent except Australia and Antarctica. They are thought to be a monophyletic grouping. Members of the subfamily are referred to as equines; the only extant equines are the horses, asses, and zebras of the genus Equus, with two other genera Haringtonhippus and Hippidion becoming extinct at the beginning of the Holocene, around 11–12,000 years ago.
Equus neogeus is an extinct species of equine native to South America during the Pleistocene. It was formerly thought to be several distinct species within the subgenus Amerhippus, but was later shown to be a single morphologically variable species. It is thought to be closely related to true horses.
Hipparionini is a tribe of three-toed horses in the subfamily Equinae. They had body forms similar to modern equines, with high-crowned teeth. They first appeared in North America during the Early Miocene around 17 million years ago, before migrating into the Old World around 11.4-11.0 million years ago. The youngest species date to the Early Pleistocene, becoming extinct following the arrives of modern equines of the genus Equus to the Old World.
Equus stenonis is an extinct species of equine that lived in Western Eurasia during the Early Pleistocene.
The Orce Man, Orce Donkey, or Venta Micena fossil is a fossil cranium fragment that was historically considered an infantile early European member of Homo. However, recent descriptions suggest that it is a member of the equine species Equus altidens.
Equus major is an extinct species of large equine native to Europe during the Early Pleistocene epoch.
Equus suessenbornensis is an extinct species of large equine native to Western Eurasia, including Europe, during the Early Pleistocene to early Middle Pleistocene.