But all that changed after aquatic amniotes started to spread.

但在水生羊膜开始传播后，一切都变了。

We're amniotes, meaning we develop in a fluid-filled egg covered in a membrane.

我们是羊膜，味着我们在充满液体蛋中发育，蛋外覆盖着一层膜。

These arid wastelands would’ve been uninhabitable for early tetrapods, but not for the amniotes.

这些干旱荒地 对于早期四足来说是不适宜居住，但对于羊膜来说却不是。

Amniotes with one temporal fenestrae are called synapsids.

具有一个颞羊膜称为突触。

Amniotes first appeared nearly 315 million years ago, in the Carboniferous Period.

羊膜首出现在大约 3.15 亿年前石炭纪时期。

By the time this catastrophe occurred, most lineages of temnospondyls had already gone extinct, under pressure from the amniotes.

到这场灾难发生时，在羊膜压力下，大多数突椎谱系已经灭绝。

Now, reptiles are amniotes, and so are mammals.

现在，爬行是羊膜，哺乳也是。

Amniotes can be subdivided into several groups based on the number of holes or fenestra in the skull.

羊膜可以根据头骨上数量细分为几个组。

Because, eggs, especially soft-shelled, leathery eggs like we'd expect to see in early amniotes, don't fossilize well.

因为，蛋，尤其是我们期望在早期羊膜中看到软壳革质蛋，不能很好地变成化石。

And amniotes with two temporal fenestrae are called diapsids.

具有两个颞羊膜被称为双。

As the Permian progressed, amniote predators like Dimetrodon, Ophiacodon, and eventually saber-toothed gorgonopsians became widespread.

随着二叠纪进展，羊膜捕食者如异齿龙、蛇夫和最终剑齿蛇目变得普遍。

So the initial 30% of the history of the amniote egg unfolded without leaving a trace.

因此，羊膜卵最初 30% 历史展开得无影无踪。

The other was a development that altered the course of life's history on planet earth: The amniote egg.

另一个是改变地球生命历史进程发展：羊膜卵。

Which group of amniotes do you think dinosaurs belong to?

你认为恐龙属于哪一组羊膜？

But on an increasingly dry planet, that gave amniotes a critical advantage.

但在一个日益干燥星球上，这给了羊膜一个关键优势。

And in lush forests dominated by ferns and ancient plants, a new kind of tetrapod was taking over: the amniotes.

在以蕨类植和古老植为主茂密森林中，一种新四足正在接管：羊膜。

Unable to compete with these amniotes, and facing a harsh new climate, terrestrial temnospondyls either vanished outright or returned to the water.

由于无法与这些羊膜竞争，并且面临着严酷新气候， 陆栖突椎要么彻底消失， 要么重返水中。

Some of our earliest fossil records of amniote eggs are from dinosaurs like Mussaurus patagonicus, which lived around 215 million years in Argentina.

我们最早一些羊膜卵化石记录来自恐龙， 例如巴塔哥尼鼠龙，它们在阿根廷生活了大约 2.15 亿年。

They saved those animals known as amniotes from extinction and may have set the stage for their invasion of dry land.

他们拯救了那些被称为羊膜免于灭绝，并可能为它们入侵旱地奠定了基础。

But the amniotes, being better adapted to drier conditions, expanded into a variety of new niches, and dominated the land.

但是羊膜更好地适应了干燥环境，扩展到各种新生态位，并主宰了土地。