Monocondylic Skull is present in
Reptilia and Aves
Aves and Mammalia
Amphibia and mammalia
All tetrapods
A unicondylar skull is a skull with a single occipital condyle. It is located at the base of the occipital bone just below the back of the skull. They are convex kidney-shaped bones. It is found in reptiles and Aves. Hence, option 1 is correct.