它们的身体呈流线型，后肢完全消失，身体上长出了尾片和喷水孔，所有这些特征都无法掩饰它们与陆生哺乳动物之间的亲缘关系。
Their streamlined bodies, the absence of hind legs, and the presence of a fluke and blowhole cannot disguise their affinities with land dwelling mammals.
像大多数的两栖动物一样，它们从幼年的“蝌蚪”状态蜕变成成年的形式——蝾螈这个物种除外，众所周知，它一生都处于幼年状态。
Like most amphibians these begin life in a juvenile "tadpole" state, then metamorphose into the adult form — except for one species, the axolotl, which famously lives its entire life as a juvenile.
每个不同的物种都依靠不同的食物为生，这使得它们在同一生态系统下更容易共存下来。
Each of the different species lived on a different diet, allowing them to easily co-exist in the same ecosystem.
应用推荐