Question

What might explain why parental care of young is common in crocodilian and birds but not in other reptiles?​

Answer 1

Answer:

They propose that the common ancestor of crocodilians dinosaurs and birds was an animal in which females provided parental care. Thus, the presence of parental care in the extant crocodilians and birds is a homologous trait, derived from the common ancestor. This is the most parsimonious explanation.