Megistotherium

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Megistotherium
Temporal range: 19.0–12.0  Ma
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Early to Middle Miocene
Megistotherium.jpg
Life restoration
Scientific classification OOjs UI icon edit-ltr.svg
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:
  • M. osteothlastes:
    • Hyainailouros osteothlastes (Morales & Pickford, 2017) [2]

Megistotherium is an extinct genus of hyaenodont belonging to the family Hyainailouridae that lived in Africa. [3] [4] [5] [6]

Contents

Taxonomy

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.

Description

Comparison of various Early to Middle Miocene hyaenodonts, including the hyainailurids Hyainailouros sulzeri (top) and Megistotherium osteothlastes (center), and teratodontid Dissopsalis pyroclasticus Megistotherium osteothlastes.JPG
Comparison of various Early to Middle Miocene hyaenodonts, including the hyainailurids Hyainailouros sulzeri (top) and Megistotherium osteothlastes (center), and teratodontid Dissopsalis pyroclasticus

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.

Paleoecology

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.

Related Research Articles

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References

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  2. Jorge Morales; Martin Pickford (2017). "New hyaenodonts (Ferae, Mammalia) from the Early Miocene of Napak (Uganda), Koru (Kenya) and Grillental (Namibia)" (PDF). Fossil Imprint. 73 (3–4): 332–359. doi:10.2478/if-2017-0019. S2CID   31350436.
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  10. 1 2 Morales, J. and M. Pickford. (2008). "Creodonts and carnivores from the Middle Miocene Muruyur Formation at Kipsaraman and Cheparawa, Baringo District, Kenya." Comptes Rendus Palevol 7 (8): 487-497
  11. J. Morales, M. Pickford, S. Fraile, M. J. Salesa and D. Soria (2003.) "Creodonta and Carnivora from Arrisdrift, early Middle Miocene of southern Namibia" Mem. Geol. Surv. Namibia 19 177–194.
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  13. Rasmussen, D. Tab; Tilden, Christopher D.; Simons, Elwyn L. (May 1989). "New specimens of the giant creodont Megistotherium (Hyaenodontidae) from Moghara, Egypt". Journal of Mammalogy. 70 (2): 442–447. doi:10.2307/1381539. JSTOR   1381539.