| 释义 |
〔ichthyornis〕Any of various extinct, toothed birds of the genusIchthyornis that existed during the Cretaceous Period. 鱼鸟：生存于白垩纪，现已灭绝的有牙齿的鱼鸟 属动物 〔sawfish〕Any of various marine fishes of the genusPristis, related to the rays and skates and having a bladelike snout with teeth along both sides. 锯鳐：任一种与鳐鱼和鲂鱼有亲缘关系的鲸 属海洋鱼类，生有刀锋般的嘴，两边皆有牙齿 〔thecodont〕Any of various extinct primitive archosaurs of the order Thecodontia of the late Permian and Triassic periods, having teeth in sockets and probably ancestral to the dinosaurs.槽齿类：二迭纪和三迭纪晚期槽齿目几种已灭绝的原始初龙，牙槽中有牙齿并且可能是恐龙的祖先 |