Batrachia

The Batrachia /bəˈtreɪkiə/ are a clade of amphibians. This group includes frogs and salamanders but not caecilians or the extinct allocaudates. Batrachia helps scientists learn how these animals are related.

The name Batrachia was first used by French zoologist Pierre André Latreille in 1800 when he studied frogs. Since then, scientists discovered that frogs and salamanders share a common ancestor.

Today, Batrachia is used in a special way called a phylogenetic sense. This means it includes the last common ancestor of frogs and salamanders and all of that ancestor's descendants. One reason scientists think frogs and salamanders are closely related is that they can both raise and lower their eyes. However, some scientists believe salamanders and caecilians might be more closely related to each other in a group called the Procera, with frogs being the sister taxon to this group.

Origins

The earliest batrachians, early forms of frogs, appeared around 250 million years ago during the Early Triassic period. These early frogs include Triadobatrachus and Czatkobatrachus. Some scientists think the split between frogs and salamanders may have happened even earlier, perhaps as far back as 367 million years ago in the Late Devonian period. But fossils from that time do not show clear evidence of modern amphibians. The groups thought to be ancestors of today's amphibians first appeared around 300 million years ago in the Late Carboniferous period.