One that's of special interest to us mammals: the cynodonts.

对我们哺乳动物来说特别有趣：犬类。

The oldest known example of a cynodont burrow is dated to around 251 million years ago — just at the boundary between the Permian Period and the Triassic, when the Great Dying was coming to a close.

目前已知最古老犬洞穴可以追溯到约2.51亿年前——正好处于二纪和三纪交界处，也就是大灭绝即将结束时候。

Meanwhile, the descendants of those little cynodonts persisted through the entire Mesozoic Era, hiding in the dinosaur's shadows.

与此同时， 那些小型犬后代在整个中生代时期都存活了下来，在恐龙阴影下隐藏着。

One way successful cynodonts, like Thrinaxodon, might have done this is through burrowing.

像棱这样成功犬可能就是通过挖洞来做到这点。

Cynodonts probably also survived thanks to their ability to avoid predators and keep a low profile.

犬很可能也因为它们能够躲避捕食者并保持低调而幸存下来。