diplocaulus, extinct amphibian from the late carboniferous to permian period

amphibian animal aquatic biology carboniferous creature cryptid cryptozoology diplocaulus diplodocidae diplodocoidea epoch era evolution extinct extinction fauna late lepospondyli magnicornis marine nature palaeontology paleoart paleontology paleozoic period perm permian phanerozoic prehistoric primeval rendering reptile salamandroides science swimming under underwater vertebrate water wildlife