Synapsids were one of the four main divisions of early reptilian life, the others being anapsids, euryapsids, and diapsids.

下亚是早期爬行动物的4个主要部之一，其他3个部分别是缺亚、亚和双亚。

So, once upon a time, were we.

我们从前曾经也是下亚动物。

The synapsids divided into four streams, only one of which survived beyond the Permian.

下亚分成四支，只有一支闯过了二叠纪。

Synapsids had one hole in their lower temples; diapsids had two; euryapsids had a single hole higher up.

下亚在颞颥下部有1个；双亚有2个；亚只有上部1个。

The Dimetrodon was in fact a synapsid.

异齿龙实际上是一种下亚动物。

So there's branchiopods, ostracods, copepods, cladocerans...and besides the crustaceans, there's a lot more.

有叶足动物、介形亚动物、桡足类动物、水蚤类动物....除了甲壳类动物外，还有很多。这是真的，还有很多。

The earliest armored fish we have fossils of is called Sacabambaspis, a member of the subclass known as Arandaspida.

我们拥有化石的最早的装甲鱼被称为 Sacabambaspis，它是 Arandaspida 亚的成员。

All modern amphibians—frogs, toads, salamanders, and the legless caecilians—belong to the same subclass of animals known as the Lissamphibia.

所有现代两栖动物——青蛙、蟾蜍、火蜥蜴和无腿的盲肠动物——都属于被称为 Lissamphibia 的同一动物亚。

And it's actually quite a small animal because contrary to all the famous theropods like the Tyrannosaurus, theropods started out as quite small animals.

与所有著名的兽脚亚目恐龙（如霸王龙）相反，事实上，它是一种体型娇小的动物，因为兽脚亚动物一开始是相当小的。

In Conseil I had a seasoned specialist in biological classification, an enthusiast who could run with acrobatic agility up and down the whole ladder of branches, groups, classes, subclasses, orders, families, genera, subgenera, species, and varieties.

在康塞尔，我有一位经验丰富的生物分类专家，一位狂热的生物分类爱好者，他可以像杂技演员一样敏捷地在分支、类群、、亚、目、科、属、亚属、种和变种的整个阶梯上上下奔跑。