The name monotreme means one hole referring to the single orifice they use for reproduction, excretion, and egg-laying.

单孔目这个词指一个孔，指的是一个用于生育、排泄，和下蛋的孔。

And these ancient egg-layers probably reproduced a lot like today's monotremes do.

这些古老的卵层可能像今天的单孔类一样繁殖。

As a monotreme, she's part of the most ancient lineage of mammals alive today.

作为单孔类，她是当今最古老的谱系的一部分。

The three modern mammal groups -- the placentals, marsupials and monotremes -- all made it.

三个现代群——盘 、有和单孔——都成功了。

There were once hundreds of monotreme species, but there are only five left: four species of echidnas and the duck-billed platypus.

曾经有好几百种单孔目，现在仅存5种：4种针鼹和鸭嘴兽。

And we think monotremes have been doing it more or less that way this whole time.

我们认为单孔类一直以来或多或少都是这样做的。

Well, there's the platypus, an egg-laying monotreme with venomous spurs.

嗯，有鸭嘴兽，一种产卵的单孔，有毒刺。

Another idea is that therians followed a path similar to the monotremes, where eggs were retained in the mother's body for longer and longer periods of time.

另一个想法是， therians 遵循类似于单孔类的路径，卵子在母亲体内的保留时间越来越长。

For crown group mammals, our most recent common ancestor is the one shared by placentals like us, marsupials like the kangaroo, and the monotremes like the platypus.

对于冠群，我们最近的共同祖先是像我们这样的盘、鼠这样的有和鸭嘴兽这样的单孔类共有的祖先。

These little creatures didn't belong to any of the three main mammal groups on the planet today—which are the placental mammals (like us), monotremes (like the platypus) and marsupials (like koalas and kangaroos).

这些小不属于当今地球上三个主要群中的任何一个——盘（如我们）、单孔类（如鸭嘴兽）和有（如考拉和鼠）。

These subtle creatures didn't belong to any of the three main mammal groups on the planet today-which are the placental mammals (like us), monotremes (like the platypus) and marsupials (like koalas and kangaroos).

这些小不属于今天地球上的三个主要群体——盘(像我们)、单孔目(像鸭嘴兽)和有(像考拉和鼠)。

The playtpus belongs to an unusual group called monotremes that diverged from the branch of the mammal family tree that leads to marsupials -- and later placentals -- around 186 million years ago.

playtpus 属于一个不寻常的类群，称为单孔类，大约在 1.86 亿年前，它从导致有类和后来的盘类的家族树的分支中分离出来。

Reptiles, amphibians, most birds, and monotremes like the platypus have a cloaca, a multipurpose swiss army knife of holes, linking the urinary, waste, and reproductive systems… I guess you could say: one ring to rule them all.

爬行、两栖、大多数鸟类和像鸭嘴兽这样的单孔类都有泄殖腔，这是一把多用途的瑞士军刀，连接着泌尿系统、废系统和生殖系统… … 我想你可以说：一环统领它们。