化石动物

To avoid sampling bias, they restricted their analysis to one group of animals—the bivalve molluscs—that fossilise well.

为了防止取样的偏颇，他将分析的对象限制在一类化保存完备动物——双壳类软体动物。

Perhaps 20 or more hominids (not all of them our ancestors) fill the gap between Lucy the australopithecine and modern humans.

在阿法南猿（露西）与现代人之间，人科动物的化也许超过20种（他是我的祖先）。