Temporal range: 360Ma Late Devonian
|Class:||"Amphibia" (wide sense)|
Daeschler et al., 1994
Hynerpeton (//; from Greek Υνηρπετον "creeping animal from Hyner") was a basal carnivorous tetrapod that lived in the lakes and estuaries of the Late Devonian period around 360 million years ago. Like many primitive tetrapods, it is sometimes referred to as an "amphibian", though it is not a true member of the modern Lissamphibia.
The structure of the shoulder girdle indicates this animal may have been one of the earlier, more primitive tetrapods to evolve during the Devonian.
In 1993, the paleontologists Ted Daeschler and Neil Shubin found the first Hynerpeton fossil, a shoulder bone, near Hyner, Pennsylvania. They were surveying the Devonian rocks of Pennsylvania in search of fossil evidence for the origin of animal limbs. The animal had a very robust shoulder, which indicated that it had powerful appendages. Only a few bones have been found from Hynerpeton, in Red Hill, Pennsylvania, U.S.A.. The known fossils include two shoulder girdles, two lower jaws, a jugal bone and some gastralia.
It is thought that that these early amphibians are descended from lobe-finned fish, such as Hyneria, whose stout fins evolved into legs and their swim bladder into lungs. It is still not known whether Hynerpeton is the direct ancestor to all later backboned land animals (including humans), but the fact that it had eight fingers, not five, suggests that it is simply our evolutionary cousin.
The Late Devonian saw the evolution of plants into trees and growing into vast forests pumping oxygen into the air, possibly giving Hynerpeton an edge because it evolved complex lungs to exploit it. Its lungs probably consisted of sacs like modern terrestrial vertebrates.
In popular culture
Hynerpeton is featured in the first episode of the 2005 documentary series Walking with Monsters. It was seen fancifully and erroneously evolving from Cephalaspis, and then walking on land. One of the Hynerpeton meets a gruesome end when a predatory Hyneria fish ambushes it at the water's edge, shortly after a mating session with a female Hynerpeton. Its eggs evolved into those of Petrolacosaurus.