Pteroplax dates from the late Carboniferous Period, about 315 million years ago.

At that site, it shared a coal-swamp lake habitat with the larger embolomere, "Eogyrinus" (whose name is a junior synonym of Pholiderpeton Huxley, 1869).

Pteroplax probably grew up to about 10 ft (3.0 m) in length and was largely aquatic, feeding upon fish and smaller tetrapods.

[citation needed] Although Pteroplax cornutus is known with total certainty only from the type specimen (an isolated skull table), Boyd (1978) described both cranial and postcranial elements from Newsham as probably belonging to this species.

[1] In her description of the large embolomere, Pholiderpeton scutigerum Huxley, Clack (1987) not only showed that "Eogyrinus" was a junior synonym of Pholiderpeton, but also removed Pteroplax from the family Eogyrinidae, noting that the lectotype skull table of P. cornutus showed similarities to embolomeres of the families Archeriidae and Proterogyrinidae.