Deinotherium Deinotherium Explosively pumped flux compression generator Category="Prehistoric mammals"
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Deinotherium
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Mammalia
Order:Proboscidea
Suborder:Deinotherioidea
Family:Deinotheriidae
Genus:Deinotherium Kaup,  1829
Species
Deinotherium bozasi Arambourg, 1934
Deinotherium giganteus Kaup, 1829
Deinotherium indicum Falconer, 1845

Deinotherium ("terrible beast") was a huge prehistoric proto-elephant that appeared in the Middle Miocene and continued until the Early Pleistocene. During that time it changed very little. In life it probably resembled modern elephants, except that its trunk was probably not as long, and it had downward curving tusks attached to the lower jaw.

Deinotherium was the second largest land mammal; only Indricotherium was larger. A big male stood about 4 to 4.5 meters tall at the shoulders. Its range covered parts of Asia, Africa, and Europe. Adrienne Mayor, in The First Fossil Hunters: Paleontology In Greek and Roman Times, has suggested that Deinothere fossils found in Greece helped generate myths of archaic giant beings. A tooth of a deinothere found on the island of Crete, in shallow marine sediments of the Miocene (see link) raises questions: was Crete connected to the mainland during that time, or did Deinotheres share the often underrated swimming abilities of modern elephants?

Evolutionary Relationships

Deinotherium is the type genus of the family Deinotheriidae, evolving from the smaller, early Miocene Prodeinotherium. These proboscideans represent a totally distinct line of evolutionary descent to that of other elephants, one that probably diverged very early in the history of the group as a whole. The large group to which elephants belong formerly contained several other related groups: besides the deinotheres there were the gomphotheres (some of which had shovel-like lower front teeth), and the mastodonts. Only elephants survive today.

Paleoecology

The way Deinotherium used its curious tusks has been much debated. It may have rooted in soil for underground plant parts like roots and tubers, pulled down branches to snap them and reach leaves, or stripped soft bark from tree trunks. Deinotherium fossils have been uncovered at several of the African sites where remains of hominids, prehistoric relatives of modern human beings, have also been found.

Characteristics

The following decsription, from Sanders 2003, is for D. giganteus but in general applies to the other two species as well

Permanent tooth formula 0-0-2-3/1-0-2-3 (Deciduous 0-0-3/1-0-3), with vertical cheek tooth replacement. Two sets of bilophodont and trilophodont teeth. Molars and rear premolars tapiroid, vertical shearing teeth; other premolars used for crushing. The Cranium is short, low, and flattened on the top (in contrast to more advanced elephants, which have a higher and more domed forehead; the implication may be that deinotheres were less intelligent than other elephants), with very large, elevated occipital condyles. The nasal opening is retracted and large, indicating a large trunk. The Rostrum is long and the rostral fossa broad. Mandibular symphyses (the lower jaw-bone) is very long and curved downward, which, with the backward curved tusks, is a distinguishing feature of the group.

Deinotherium is distinguished from its predecessor Prodeinotherium by its much greater size, greater crown dimensions, and reduced development of posterior cingula ornamentation in the second and third Molar.

Species

Three species are recognised, all of great size.

Deinotherium giganteus Kaup 1929

Deinotherium giganteus is the Type species, and is described above. It is primarily a late Miocene species, most common in Europe, and is the only species known from the circum-Mediterranean. Its last reported occurrence is from the middle Pliocene of Romania.

An entire skull, found in the Lower Pliocene beds of Eppelsheim, Hesse-Darmstadt in 1836, measured 4 ft (1.2 meters) in length and 3 ft (90 cm) in breadth, indicating an animal exceeding modern elephants in size.

Deinotherium indicum Falconer 1945

Deinotherium indicum is the Asian species, known from India and Pakistan. It is distinguished by a more robust dentry and p4-m3 intravalley tubercles. D. indicum appears in the middle Miocene, and is most common in the late Miocene. It disappears from the fossil record about 7 million years ago (late Miocene).

Deinotherium bozasi Arambourg 1934

Deinotherium bozasi is the African species. It is characterised by a narrower rostral trough and smaller but higher nasal aperture, and a higher and narrower cranium, and shorter mandibular symphysis, than the other two species. D. bozasi appears at the beginning of the late Miocene, and continues there after the other two species have died out elsewhere. The youngest fossils are from the Kanjera Formation, Kenya, about a million years old (early Pleistocene)

References and External links