Acta Palaeontologica Polonica

Evolutionary radiation of the cheek teeth of Cretaceous placentals

Percy M. Butler

Acta Palaeontologica Polonica 22 (3), 1977: 241-271

Included is a comparative study of the molars and posterior premolars of the Cretaceous placentals. Particular attention is paid to occlusal relations. An attempt is made to identify primitive characters, and the advance of each genus from the primitve condition is analysed. It is found that nearly all known genera are on different lines of evolution, indicating that a major radiation of placentals was taking place during the Cretaceous.

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