Explanation

Reptilians, birds and mammals are amniotes. Amphibians like salamander and Necturus (the mud puppy) are not amniotes. Angius is the glass snake (Reptilia), Eudynamis is the cuckoo or koel (Aves) and Pteropus the large bat or flying fox is a mammal are all amniotes. All amniotes have special embryonic membranes (amnion, chorion, allantois, yolk sac) that surround the embryo during development