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Arctocyonidae : ウィキペディア英語版 | Arctocyonidae
Arctocyonidae (from Greek ''arktos'' ''kyôn'', "bear/dog-like") is an extinct family of unspecialized, primitive mammals with more than 20 genera. The family was most abundant during the Paleocene, but extant from the late Cretaceous to the early Eocene ().
These animals are thought to be the ancestors of the orders Mesonychia and Cetartiodactyla, although some morphological studies have suggested that Arctocyonidae is a 'wastebasket' group for basal ungulates, and is in fact, polyphyletic == Characteristics == Arctocyonid skulls had large canines and relatively sharp teeth and were thus superficially similar to those of modern carnivores. However, arctocyanid teeth were not specialized for slicing meat; these animals were probably omnivorous and definitely the least herbivorous of the condylarths. Arctocyonid teeth show much individual variation and, because many members of this family are only known from fossil teeth, the taxonomy of the genera is highly unstable.
They had relatively short limbs lacking the specializations associated with ungulates (e.g. reduced side digits, fused bones, and hoofs),〔 and long, heavy tails. Their primitive anatomy makes it unlikely that they were able to run down prey, but with their powerful proportions, claws, and long canines, they may have been able to overpower smaller animals in surprise attacks.
抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Arctocyonidae」の詳細全文を読む
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