What is Lissamphibia?
Lissamphibia is the only surviving subclass of amphibians — the other two, Lepospondyli (lepospondyls) and Labyrinthodontia (labyrinthodonts) having gone extinct in the Permian (290 million years ago) and the Cretaceous (120 mya) respectively. Labyrinthodonts were already going downhill by the Permian-Triassic extinction event (251 mya) and especially by the Late Triassic (210 mya), around the same time that dinosaurs became dominant. Lissamphibia consists of three orders: frogs/toads, salamanders, and the limbless caecilans. The earliest known members of subclass Amphibia are basal temnospondyls dated to 340 million years ago, in the Early Carboniferous. These fish-like tetrapods had sprawling stances that put them close to the ground and were relatively large, 3-5 ft in length, like the lobe-finned fish they evolved from. They expended so much energy on walking that they would have been frequently exhausted and in need of rest. Thankfully for them, since carnivorous tetrapods had no
