And this may have happened more than once in the late Proterozoic.

而 元古代可能不止一次发生过。

Nuna existed from 1.8 to 1.4 billion years ago, in the middle of the Proterozoic Eon.

努纳存于 1.8 到 14 亿 年前，元古代纪元中期。

Scientists believe this early time in motility may have faced a setback soon after the Paleoproterozoic Era, about the time of the Gabon fossils.

科学家们认为，种早期的动性可能古元古代（大约是加蓬化石年代）后不久就开始发生倒退。

Primitive ungulates survived and grew after the K-Pg Extinction thanks  to evolutionary innovations like specialized teeth for chewing and grinding vegetation.

原始有蹄类动物纳-古元古代灭绝之后幸存下并繁衍，要归功于诸如用于咀嚼和磨碎植物的专门牙齿等进化创新。