Dimetrodon dominated the last period of the Palaeozoic, the Permian Period, alongside many other animals that can seem at once familiar and … not.

二齿兽在古生代的最后个时期——二叠纪，与许多其他看起来既悉悉的动物共存并占据主导地位。

But certain Jurassic and Triassic forms are now commonly admitted to be teleostean; and even some palaeozoic forms have thus been classed by one high authority.

但是某些罗纪和三叠纪的形式现在普遍被认为是硬骨动物；些古生代类型也因此被位权威机构分类。

With respect to the terrestrial productions which lived during the Secondary and Palaeozoic periods, it is superfluous to state that our evidence is fragmentary in an extreme degree.

于生活在第二纪和古生代的陆生生物，说我们的证据极其零碎是多余的。

With its lizard-like appearance and that distinctive sail on it back, Dimetrodon is practically the mascot of the Palaeozoic Era, a time before flowers, birds, mammals, and even crocodiles.

凭借其蜥蜴般的外观和独特的背帆，异齿龙实际上是古生代的吉祥物，那时候还没有花朵、鸟类、哺乳动物，鳄鱼。