As the Temnsospondyli survived for
220 million years, they can be split into three main groups. Those that
originated in the Early Carboniferous, those found after the Late
Permian/Early Triassic and those found after the Early Jurassic. The
fossil record of the temnospondyls is relatively good. There are hundreds if not thousands of
fossils for most of the common species. Eryops
is one of the most common species found and at 2m in length also one of
the biggest for its time. The fossil record is also good enough for
comments to be made upon neoteny and larval stages of the different
species. This is something that the Temnospondyli shares in common with
the more commonly known Lissamphibia (modern frogs, toads, salamanders,
newts and caecelians). Some of these Larval forms are relatively
common, eg. Branchiosaurus. Indeed fossils of this species can be bought for as little as $70 or £45.
links below will take you to a page detailing which age of
temnospondyls you are looking for.