A newly discovered eel that inhabits an undersea cave in the Pacific Ocean has been dubbed a "living fossil" because of its primitive features.

一种最近在太平洋海底洞穴被发现的鳝鱼因其原始的特征而被冠以“活化石”称号。

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"There are primitive features in the skeleton of floresiensis which for me suggests that it comes from quite a primitive form of human: one that may have been around two million years ago rather than one million years ago".

BBC: Study backs 'hobbit' island dwarfism theory

The combination of features indicates that the primitive pterodactyls evolved relatively quickly, and that certain groups of features changed at the same time.

CNN: Pterodactyl fossil fills gaps in evolutionary tale

Instead, some features shift to the advanced form at the beginning of the process, while others stay resolutely primitive until near the end.

ECONOMIST: How new groups of creatures emerge