Megantereon

Megantereon Temporal range: Early Pliocene to Middle Pleistocene
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Felidae
Subfamily:	†Machairodontinae
Genus:	†Megantereon Croizet & Jobert, 1828

Megantereon was an ancient machairodontine saber-toothed cat that lived in North America, Eurasia, and Africa. It may be the ancestor of Smilodon.

Fossil range

Fossil fragments have been found in Africa, Eurasia, and North America. The oldest confirmed records of Megantereon are known from the Pliocene of North America and are dated to about 4.5 Million years. About 3-3.5 Million years ago it is firmly recorded also from Africa, about 2.5 to 2 Million years ago also from Asia. In Europe the oldest remains are known from Les Etouaries (France), a site which is now dated to less than 2.5 Million years old. Therefore a North American origin of Megantereon has been suggested. However, recent findings of fragmentary fossils from Kenya and Chad, which are dated to about 5.7 and 7 Million years, respectively, are probably from Megantereon. If these identifications are right, they would represent the oldest Megantereon fossils in the world. The new findings therefore indicate an origin of Megantereon in the Late Miocene of Africa.^[1]

At the end of the Pliocene it evolved into the larger Smilodon in North America, while it survived in the Old World until the middle Pleistocene. The youngest remains of Megantereon from east Africa are about 1.5 million years old. In southern Africa the genus is recorded from Elandsfontein, a site dated to around 700,000-400,000 years old. Remains from Untermaßfeld show that Megantereon lived until 900,000 years ago in Europe. In Asia it may have survived until 500,000 years ago, as it is recorded together with Homo erectus at the famous site of Zho-Khou-Dien in China. The only full skeleton was found in Senéze, France.

Morphology

Megantereon was built like a modern jaguar or somewhat heavier. It had stocky forelimbs with the lower half of these forelimbs lion-sized. It had large neck muscles designed to deliver a powerful shearing bite. The elongated upper canines were protected by flanges at the mandible. Mauricio Anton's reconstruction in The big cats and their fossil relatives depicts the full specimen found at Seneze in France as 72 centimetres (28 in) at the shoulder. The largest specimens with an estimated body weight of 90–150 kilograms (200–330 lb) (average 120 kilograms (260 lb)) are known from India. Medium sized species of Megantereon are known from other parts of Eurasia and the Pliocene of North America. The smallest species from Africa and the lower Pleistocene of Europe have been estimated to only 60–70 kilograms (130–150 lb).^[2] However, other sources estimated Megantereon from the European lower Pleistocene at 100–160 kilograms (220–350 lb).^[3]

Hunting technique

In Europe, Megantereon may have preyed on larger artiodactyls, horses or the young of rhinos and elephants.^[4] It is unlikely that Megantereon simply bit its prey as the long, sabre-teeth that Smilodon is famed for are not strong enough to leave buried inside a struggling prey animal: the teeth would break off. It is possible that they bit their prey and then allowed it to bleed to death, but then they would have to protect that animal from other predators and thus their tactic for killing remains uncertain. It is now generally thought that Megantereon, like other saber-toothed cats, used its long saber teeth to deliver a killing throat bite, severing most of the major nerves and blood vessels. While the teeth would still risk damage, the prey animal would be killed quickly enough that any struggles would be feeble at best.^[5]

Species

The number of species is unclear, with some known from only fragmentary evidence. Some researchers have argued that three species should be distinguished: M. cultridens from North America, Asia (except the Indian subcontinent) and the European Pliocene, M. whitei from Africa and the European Lower Pleistocene and M. falconeri from India.^[6] Therefore, the true number of species may be less than the full list of described species reproduced below.^[7]

• Megantereon cultridens (Cuvier, 1824)
• Megantereon ekidoit Werdelin & Lewis, 2000
• Megantereon eurynodon Ewer, 1955
• Megantereon falconeri Pomel, 1853
• Megantereon gracilis Broom & Schepers, 1946
• Megantereon hesperus (Gazin, 1933)
• Megantereon inexpectatus Teilhard de Chardin, 1939
• Megantereon megantereon Croizet & Jobert, 1828
• Megantereon nihowanensis Teilhard de Chardin & Piveteau, 1930
• Megantereon spiryleris (?)
• Megantereon vakhshensis (?)
• Megantereon whitei Broom, 1937

Popular culture

Megantereon was depicted in a Discovery Channel TV Series, Before We Ruled the Earth, as a nocturnal hunter that preyed on Homo ergaster.

Literature

• A. Turner: The big cats and their fossil relatives. Columbia University Press, 1997, ISBN 0-231-10229-1
• Jordi Augusti: Mammoths, Sabertooths and Hominids 65 Million Years of Mammalian Evolution in Europe. Columbia University Press, 2002, ISBN 0-231-11640-3
• D. Mol / W. v. Logchem / K. v. Hooijdonk / R. Bakker: The Saber-Toothed Cat, DrukWare, Norg 2008, ISBN 978-90-78707-04-2

References

1. ^ De Bonis, L., Peigne, S., Mackaye, H. T., Likius, A., Vignaud, P., Brunet, M. (2010). New sabre-toothed cats in the Late Miocene of Toros Menalla (Chad). Systematic palaeontology (Vertebrate palaeontology) . Palevol 9, 221-227.
2. ^ B. M. Navarro and P. Palmqvist: Presence of the African Machairodont Megantereon whitei (Broom, 1937) (Felidae, Carnivora, Mammalia) in the Lower Pleistocene Site of Venta Micena (Orce, Granada, Spain), with some Considerations on the Origin, Evolution and Dispersal of the Genus. Journal of Archaeological Science (1995) 22, 569–582.
3. ^ N. Garcia and E. Virgos: Evolution of community in several carnivore palaeoguilds from the European Pleistocene: the role of intraspecific competition. Lethaia 40 (2007)
4. ^ Per Christiansen, Jan S. Adolfssen. Osteology and ecology of Megantereon cultridens SE311 (Mammalia; Felidae; Machairodontinae), a sabrecat from the Late Pliocene – Early Pleistocene of Senéze, France. Zoological Journal of the Linnean Society, 2007, 151, 833–884. With 29 figures.
5. ^ Turner, Alan (1997). The Big Cats and their fossil relatives. New York: Columbia University Press. p. 55. ISBN 0-231-10228-3. 
6. ^ B. M. Navarro and P. Palmqvist: Presence of the African Machairodont Megantereon whitei (Broom, 1937) (Felidae, Carnivora, Mammalia) in the Lower Pleistocene Site of Venta Micena (Orce, Granada, Spain), with some Considerations on the Origin, Evolution and Dispersal of the Genus. Journal of Archaeological Science (1995) 22, 569-582.
7. ^ Turner, A (1987). "Megantereon cultridens (Cuvier) (Mammalia, Felidae, Machairodontinae) from Plio-Pleistocene Deposits in Africa and Eurasia, with Comments on Dispersal and the Possibility of a New World Origin". Journal of Paleontology 61 (6): 1256–1268. JSTOR 1305213.