Crocodilians are classified as reptiles; however, they share a common ancestor with birds, which are not classified as reptiles. Therefore, Reptilia is a ____ taxon.
A) monophyletic
B) polyphyletic
C) paraphyletic
D) genetically unrelated
E) homoplastic

Question

Quizplus · Accepted Answer

Reptilia is considered a paraphyletic group because it includes some but not all of the descendants of their most recent common ancestor. Since birds are descended from within the group that includes reptiles but are not classified as reptiles themselves, the group excludes some descendants (birds) of their common ancestor, making it paraphyletic.

Crocodilians Are Classified as Reptiles; However, They Share a Common