This article possibly contains original research .(November 2023) |
Megistotherium Temporal range: Miocene Early to Middle | |
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Life restoration | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | † Hyaenodonta |
Family: | † Hyainailouridae |
Subfamily: | † Hyainailourinae |
Genus: | † Megistotherium Savage, 1973 [1] |
Type species | |
†Megistotherium osteothlastes Savage, 1973 | |
Synonyms | |
synonyms of species:
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Megistotherium is an extinct genus of hyaenodont belonging to the family Hyainailouridae that lived in Africa. [3] [4] [5] [6]
The name of this genus comes from Ancient Greek μέγιστον (mégiston) 'greatest' and from Ancient Greek θήριον (thēríon) 'beast'. [1]
The name of species Megistotherium osteothlastes comes from Ancient Greek ὀστέον (ostéon) 'bone' and from Ancient Greek θλᾰστός (thlastos) 'crushed' or 'bruised' (with -es being an agent noun: 'bone-crusher'). [1]
The family Hyainailouridae comprised a diverse group of hyaenodont predators that were most successful during the Eocene before being possibly ecologically displaced by the order Carnivora during the late Oligocene. Megistotherium emerged in the Miocene towards the end of the hyaenodonts' flourishing; it was a part of a radiation of African hyaenodontids that occurred at that time. Hyainailouros sulzeri is very closely related to Megistotherium, extremely similar in size, structure and ratios - with a long tail, short limbs and robust body. [7] Other authorities [8] [9] [10] have suggested that Megistotherium is actually a junior synonym of Hyainailouros sulzeri, which is known by an almost complete skeleton, among other remains, and has been found in Europe, Asia and Namibia, [11] and therefore comes from the same localities.
Megistotherium osteothlastes is the only known species from this genus, and it was a large hyainailourid that lived during the Early and Middle Miocene. Its remains have been found in the Ngorora and Muruyur Formations of Kenya, Egypt, [9] Namibia, Uganda [10] and Libya. Named by Robert Savage in 1973, [1] Megistotherium is one of the largest known hyaenodonts. Like the other hyaenodonts, it had an enormous skull relative to its body; up to 66.4 cm (2 ft 2.1 in) in length [1] and a body mass estimated at 500 kg (1,100 lb). [12] The carnassial teeth of Megistotherium (like those of other hyaenodonts) were the upper first molars, and overlapped with their lower molar counterparts like scissors to form a formidable and powerful shearing action.
The land that is now the Sahara desert was much more fertile in the Miocene. A considerable amount of it was grassland and rainfall was plentiful. Lakes and ponds provided water for large fauna, which provided Megistotherium and other predators with an ample supply of prey. Large hyaenodontids like this one could have originally evolved as specialized predators or scavengers of large African herbivores. [13] Gomphothere bones have been found with its fossils, indicating that Megistotherium may have hunted them for food.
Amphicyonidae is an extinct family of terrestrial carnivorans belonging to the suborder Caniformia. They first appeared in North America in the middle Eocene, spread to Europe by the late Eocene, and further spread to Asia and Africa by the early Miocene. They had largely disappeared worldwide by the late Miocene, with the latest recorded species at the end of the Miocene in Africa. They were among the first carnivorans to evolve large body size. Amphicyonids are colloquially referred to as "bear-dogs".
Creodonta is a former order of extinct carnivorous placental mammals that lived from the early Paleocene to the late Miocene epochs in North America, Europe, Asia and Africa. Originally thought to be a single group of animals ancestral to the modern Carnivora, this order is now usually considered a polyphyletic assemblage of two different groups, the oxyaenids and the hyaenodontids, not a natural group. Oxyaenids are first known from the Palaeocene of North America, while hyaenodonts hail from the Palaeocene of Africa.
Hyaenodon ("hyena-tooth") is an extinct genus of carnivorous placental mammals from extinct tribe Hyaenodontini within extinct subfamily Hyaenodontinae, that lived in Eurasia and North America from the middle Eocene, throughout the Oligocene, to the early Miocene.
Dissopsalis is a genus of teratodontine hyaenodonts of the tribe Dissopsalini. The older species, D. pyroclasticus, lived in Kenya during the middle Miocene, while the type species, D. carnifex, lived in Pakistan and India during the middle to late Miocene.
Pterodon is an extinct genus of hyaenodont in the family Hyainailouridae, containing five species. The type species Pterodon dasyuroides is known exclusively from the late Eocene to the earliest Oligocene of western Europe. The genus was first erected by the French zoologist Henri Marie Ducrotay de Blainville in 1839, who said that Georges Cuvier presented one of its fossils to a conference in 1828 but died before he could make a formal description of it. It was the second hyaenodont genus with taxonomic validity after Hyaenodon, but this resulted in taxonomic confusion over the validities of the two genera by other taxonomists. Although the taxonomic status of Pterodon was revised during the late 19th and early 20th centuries, it became a wastebasket taxon for other hyaenodont species found in Africa and Asia. Today, only the type species is recognized as belonging to the genus while four others are pending reassessment to other genera.
Hyainailouros ("hyena-cat") is an extinct polyphyletic genus of hyaenodont belonging to the family Hyainailouridae that lived during the early to middle Miocene, of which there were at least three species spread across Europe, Africa, and Asia.
Sivapterodon is an extinct genus of hyainailourid hyaenodont mammal of the subfamily Hyainailourinae that lived in Pakistan during the middle Miocene.
Hyaenodonta is an extinct order of hypercarnivorous placental mammals of clade Pan-Carnivora from mirorder Ferae. Hyaenodonts were important mammalian predators that arose during the early Paleocene in Europe and persisted well into the late Miocene.
Hyainailouridae ("hyena-cats") is a family of extinct predatory mammals within the superfamily Hyainailouroidea within extinct order Hyaenodonta. Hyaenodontids arose during the middle Eocene and persisted well into the middle Miocene. Fossils of this group have been found in Asia, Africa, North America and Europe.
Teratodontinae is a subfamily of extinct hyaenodonts. Fossil remains of these mammals are known from Middle Eocene to Late Miocene deposits in Africa, the Arabian Peninsula, and Asia.
Isohyaenodon is an extinct polyphyletic genus of hyainailourid hyaenodont mammal from the subfamily Hyainailourinae). Remains are known from early to middle Miocene deposits in Kenya, East Africa.
Metapterodon is an extinct genus of hyainailourid hyaenodonts of the subfamily Hyainailourinae, that lived in Africa during the early Oligocene to early Miocene. Fossils of Metapterodon were recovered from the Egypt, Uganda, Elisabeth Bay Formation in Namibia, and Rusinga Island and Karungu in Kenya.
Simbakubwa is an extinct genus of hyaenodonts to the family Hyainailourinae that lived in Kenya during the early Miocene.
The Ngorora Formation is a geological formation in Kenya preserving fossils dating to the Miocene. The uppermost member of the formation shows sign of a faunal turnover that occurred around 11 to 10.5 million years ago, coinciding with faunal changes elsewhere in the world. This turnover includes the arrival of the horse Hipparion in East Africa. The Ngorora Formation was initially mapped by G.R. Chapman in collaboration with the East African Geological Research Unit (EAGRU) and formally described by Bishop & Chapman in 1970. Major fossil finds were made in the early 1970s, with expeditions to the area recovering thousands of mammal, fish and mollusc remains alongside less common fossil material of birds and reptiles.
Dissopsalini is an extinct tribe of teratodontid hyaenodonts. Fossil remains of these mammals are known from early to late Miocene deposits in Asia and Africa.
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.
Diamantofelis is an extinct genus of felids that lived in what is now Namibia during the Early Miocene. It contains a single species, Diamantofelis ferox.
Namafelis is an extinct genus of felids that lived in what is now Namibia during the Early Miocene. It contains a single species, Namafelis minor. Closely related to Diamantofelis, it is of “Pseudaelurus-grade”, and therefore a rather basal member of the cat family.
Myacyon is an extinct genus of large sized carnivoran mammals, belonging to the family Amphicyonidae, that lived in Africa during the Miocene epoch. Due to the limited scope and fragmentary nature of the severely damaged holotype, as well as the illustrations in its descriptions, which have been called inadequate, usage of this genus poses serious issues. However, it is notable for being one of the last surviving members of its family and its adaptions to hypercarnivory. Its relationships to other amphicyonids are obscure, and it is not closely related to Bonisicyon, the other late surviving African genus, although it has been proposed that it descends from a species of Cynelos or Namibiocyon.
Namibiocyon is an extinct genus of carnivoran mammals, belonging to the family Amphicyonidae, that lived in Namibia during the Early Miocene epoch. Before the erection of this taxon in 2022, the type and only species, N. ginsburgi, had been assigned to a variety of other genera. It is notable for its adaptions toward hypercarnivory.