Earliest frogs and toads

Frogs and toads belong to the taxonomic superorder of amphibians called Salientia. The two earliest-known fossil species belonging to this superorder both date back to the early Triassic Period, approximately 250 million years ago, and are termed proto-frogs or proto-salientians. One of these is Triadobatrachus massinoti from Madagascar; the other is Czatkobatrachus polonicus from Poland. Triadobatrachus massinoti possessed certain anatomical characteristics that distinguished it from modern frogs. These include unfused tail vertebrae, more back vertebrae, unfused tibia and fibula bones in the lower legs, and a longer body. Czatkobatrachus polonicus is currently known only from fragmentary remains.