If you're wondering whether birds are reptiles, know this: The reptile family tree is more varied and diverse than you might realize.

The Megalosaurus is essential to paleontology. Learn what discoveries made this dinosaur important.

总的来说，虽然有的古生物学者把包括始祖鸟在内的所有传统鸟翼类，都称为鸟类。但也有的古生物学者并不认同这种看法，尤其是在严肃层面讨论时，往往会把始祖鸟等恐龙特征较多的排除在外。

So "if you go further back along the branches of the tree of life, you find that [Neornithes] also belong to the more inclusive clade Theropoda," a group of two-legged and mostly meat-eating ...

谢邀。 非常有意义的发现！ 要深入了解这个发现的重大意义，需要先了解鸟类的演化过程。 大多数人往往只知道鸟类是恐龙的一支，再详细点可能了解始祖鸟，再细化就不知道。 但恐怕很多人不知道，始祖鸟几乎要被开除鸟籍了。即便不开除鸟籍，也不是最早的鸟类。 这是始祖鸟： 这是今天的鸟类： 始祖鸟和今天的鸟类，一眼看过去的最大区别是什么？ 是尾巴！

In a new study published in the journal PLoS ONE, paleontologists analyzed the fossilized remains of the alvarezsaurid dinosaur Bonapartenykus from the Allen Formation of Patagonia. Their results shed ...