A close relative of the similarly named Diplocaulus
, Diploceraspis was an odd-looking amphibian of the Permian
period, characterized by its oversized, boomerang-shaped head (which probably kept it from being swallowed whole by predators). Specimens of Diploceraspis have been discovered in both West Virginia and neighboring Ohio. More about prehistoric amphibians
Greererpeton occupies an odd position between the earliest tetrapods (lobe-finned fish that climbed onto land) and the first true amphibians. This middle Carboniferous
creature spent all of its time in the water, leading some paleontologists to conclude that it "de-evolved" from its amphibian ancestors back in the tetrapod direction! More about tetrapods
The three-foot-long Proterogyrinus was the apex predator of late Carboniferous West Virginia, when North America was just beginning to be populated by air-breathing amphibians. This wriggly critter retained some evolutionary traces of its tetrapod ancestors, most notably its broad, fish-like tail, which was nearly as long as the rest of its body.
Oddly enough, Lithostrotionella is the official state gemstone
of West Virginia, even though it wasn't a mineral, but a prehistoric coral that lived about 340 million years ago (when much of eastern North America was submerged under water). Corals are colonial, marine-dwelling animals, and not plants, as many people mistakenly believe.