Megantereon

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

Megantereon was a genus of prehistoric machairodontine saber-toothed cat that lived in North America, Eurasia, and Africa. It may have been the ancestor of Smilodon.

Fossil range

M. cultridens skull

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 (for example, in Kenya), 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.

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.

Description

Restoration

Megantereon was built like a large modern jaguar, but 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). However, these estimations were obtained from comparisons of the carnassial teeth. Younger estimations, which are based on the postcranial skeleton, lead to body weights of about 100 kilograms (220 lb) for the smaller specimens. In agreement with that, more recent sources estimated Megantereon from the European lower Pleistocene at 100–160 kilograms (220–350 lb).

Palaeobiology

Teeth and jaw

In Europe, Megantereon may have preyed on larger artiodactyls, horses or the young of rhinos and elephants. 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. and the European Pliocene, M. whitei from Africa and the European Lower Pleistocene. Therefore, the true number of species may be less than the full list of described species reproduced below.

• Megantereon cultridens (Cuvier, 1824) (type species)
• Megantereon ekidoit Werdelin & Lewis, 2000
• Megantereon hesperus (Gazin, 1933)
• Megantereon inexpectatus Teilhard de Chardin, 1939
• Megantereon microta Zhu et. al., 2015
• Megantereon nihowanensis Teilhard de Chardin & Piveteau, 1930
• Megantereon vakhshensis Sarapov, 1986
• Megantereon whitei Broom, 1937

Further reading

• Augustí, Jordi. Mammoths, Sabertooths and Hominids: 65 Million Years of Mammalian Evolution in Europe. New York: Columbia University Press, 2002, ISBN 0-231-11640-3.
• Mol, Dick, Wilrie van Logchem, Kees van Hooijdonk and Remie Bakker. The Saber-Toothed Cat of the North Sea. Uitgeverij DrukWare, Norg 2008, ISBN 978-90-78707-04-2.
• Turner, Alan. The Big Cats and Their Fossil Relatives: An Illustrated Guide to their Evolution and Natural History. Illustrations by Mauricio Anton. New York: Columbia University Press, 1997, ISBN 0-231-10229-1.