The tooth of an archosaur, left, which was a direct ancestor of many dinosaurs, and the complete skeleton, including soft tissue of a horseshoe crab, right.

左图，是古蜥蜴的牙齿，它是很多恐龙的直系祖先；右图，是一个完整的马蹄蟹的头盖骨。

Dinosaurs split off early from the crocodile family tree, paleontologists suggested Wednesday, based on the discovery of a 240-million-year-old fossil "archosaur."

恐龙在很早以前就从鳄鱼家族的家谱中分化出来了，这一论点是古生物学家在周三根据新发现的二百四十万年前的祖龙化石提出的。

Archaelogists also discovered a number of larger land-based animals and plant fossils including the sharp tooth of an archosaur and the remains of some ancient conifer-like plants.

考古学家同事发现许多大型陆地动物和植物化石，比如一只祖龙的尖牙和一些古代针叶松类型的植物化石。

The find moves several species thought to belong to crocodile family fossils to the archosaur side of species lines, and indicates the dinosaur family had deeper roots than previously suspected.

这一发现推动了一些之前被认为是属于鳄鱼家族化石中的物种向祖龙这一边的进化链靠拢，这也证实了恐龙家族有着比之前的推测更深厚的根源所在。