Tetralophodon

Tetralophodon Temporal range: Miocene–Pliocene PreЄ Є O S D C P T J K Pg N
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Fossil skull and tusks of T. longirostris, from Ballestar, Spain at the Museu Geològic del Seminari de Barcelona, Barcelona
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Synapsida
Class:	Mammalia
Order:	Proboscidea
Family:	†Gomphotheriidae
Genus:	†Tetralophodon
Species
†T. longirostris (Kaup, 1832) (type) †T. punjabensis †T. xiaolongtanensis

Tetralophodon ("four-ridged tooth") is an extinct gomphothere genus belonging to the family Gomphotheriidae.

Etymology

The genus Tetralophodon (meaning "four-ridged tooth") was named in the mid-19th century with the discovery of the specialized teeth.

Description

File:Gomphotheriidae - Tetralophodon longirostris-001.JPG

Fossil jaws of T. longirostris, at the Naturhistorisches Museum, Vienna

Tetralophodon was an elephant-like animal which existed through the late Miocene and early Pliocene epoches, approximately 2.5 million years ago.

Like typical gomphotheres, mastodons with four tusks, Tetralophodon had four tusks and a trunk. In fact, also this animal had two further tusks protruding from the jaw. The overall appearance recalled Gomphotherium, the best known genus of the family Gomphotheriidae.

Their body is believed to be about 3 m (10 ft) tall and 2-3 ton in weight, about the size of the present Asian elephant, with the long trunk and incisors ranging up to 2 m (6.6 ft) long. These incisors are believed to be utilized as a defense mechanism

The large, four-cusped cheek teeth of these animals are approximately 60 mm (2.4 in) by 80 mm (3.1 in), about 6 times the size of a normal human tooth. These low-crowned, bunodont teeth are designed for crushing and grinding, compared with other mammals during this era that had sharp teeth used for cutting. The teeth of the tetralophodon indicate a diet of large fruits and vegetables. This diet is aided by the large size and long trunks of the elephantiods that enable these mammals to reach tall, fruit-bearing trees.

Some features, mainly concerning the teeth, would seem to place Tetralophodon close to the origin of today's elephants. The molars, in particular, are more advanced and specialized than those of the other gomphotheres.

Distribution

Molar teeth of T. punjabensis at the Museo Civico di Storia Naturale di Verona, Verona

These animals were very widespread and successful proboscideans. Their fossils have been found in the late Miocene and early Pliocene epochs of Europe, Asia, and Africa. Most fossil records of tetralophodon are of four-ridged teeth. The North American species, T. campester and T. fricki, have been moved to the genus Pediolophodon in 2007.

The majority of the gomphotheres went extinct at the end of the Pleistocene era, during what has been named the PT extinction. While the reason for this extinction is still debated, what is known is that these massive elephantoids under the genus Tetralophodon did not survive.

See also

• Gomphotherium
• Rhynchotherium