Answer:
You either are referring to the fish Chordate, or the animal classification. In the case of the classification it is literally any animal that has developed any sort of dorsal fin, for example some snakes can fall under this classification.
The correct answer is transitional.
Gerobatrachus refers to an extinct genus of amphibamid temnospondyl, which thrived in the initial Permian, that is, about 290 mya, in the region, which is now known as Baylor County, Texas. The transitional form of fossils are those that demonstrate the intermediate form between the two distinct living species, it could be in a form of an ancestor and its descendants. It is considered that the frogs and salamanders have evolved from a common ancestor of primitive amphibian tetrapod subclass known as Temnospondyli.
Compounds that do not contain carbon
They are adapted for photosynthesis by having a large surface area, and contain openings, called stomata to allow carbon dioxide into the leaf and oxygen out