THE EVOLUTION OF THE ELEPHANT
Fig. 4.—Evolution of head and molar teeth of mastodons and elephants. A, A′, Elephas, Pleistocene; B, Stegodon, Pliocene; C, C′, Mastodon, Pleistocene; D, D′, Trilophodon, Miocene; E, E′, Palaeomastodon, Oligocene; F, F′, Moeritherium, Eocene. (After Lull.)
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