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.

凭借其蜥蜴般外观和独特背帆，异齿龙实际上代吉祥，那时候还没有花朵、鸟类、哺乳动，甚至鳄鱼。

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.

至活在第二纪和代陆，说我们证据极其零碎多余。

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.

但某些侏罗纪和三叠纪形式现在普遍被认为硬骨动；甚至一些代类型也因此被一位权威机构分类。

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

二齿兽在代最后一个时期——二叠纪，与许多其他看起来既熟悉又不熟悉动共存并占据主导地位。