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a large unique group of extinct mammals of the order Proboscidea. The mastodonts lived in the late Paleocene and in the Anthropogenic period. In Europe and Asia they became extinct at the end of the Neocene, and in Africa and North America in the Anthropogenic period. The height of the animals ranged from 1.5 to 3.2 m.
A distinction is made between two groups of mastodonts: mastodonts in which the tooth crowns were composed of many individual conical cusps and mastodonts in which the tooth crowns were composed of transverse crests. Elephants are descended from the second group. The early mastodonts had a pair of tusks—actually enlarged incisors—in the upper and lower jaws. Later mastodonts had only one pair of tusks, in the upper jaw. As the mastodont evolved, its skeleton, including the skull, became increasingly more massive. Mastodonts constituted different ecotypes, inhabiting swamps, forests, and forest-steppes. Their remains in what is the now the USSR have been found in Kazakhstan, Middle Asia, and the Southern European part. Mastodonts are important for the stratigraphy of the continental deposits of the Cenozoic era.