1.In this, Erythrosuchids constitute an Archosauriformes clade that is an outgroup to the Archosauria proper.

1.依照这个方法，引鳄科构成一个动物演化，是的。

2.What does group membership mean? How should we measure it? Ingroup vs. outgroup.

2.会员的意思是什麽？我们应如何衡量？圈内与圈。