Eryops - (pronounced EAR-ee-ops)

Eryops (meaning: drawn-out face) because most of its skull was in front of its eyes, is a genus of extinct, semi-aquatic amphibian. The primary species of Eryops has been named Eryops megacephalus ('big head').

 

Eryops was a common, primitive amphibian that lived in swamps during the Permian period, long before dinosaurs evolved. It was a carnivore and a fierce predator on land and in the water and may have eaten mostly fish, small reptiles and amphibians. A large supply of terrestrial invertebrates were also abundant at the time, and this may have provided a fairly adequate food supply in itself. The amphibian would grasp its prey and, lacking any chewing mechanism, toss its head up and backwards, throwing the prey farther back into its mouth. Such feeding is seen today in the crocodile and alligator.

Eryops’ eye sockets were large and directed upward. The body was low to the ground and supported by short, massive limbs. The tail was short, suggesting the animal was not a fast or powerful swimmer. The flat skull with the large eyes and nostrils placed on the top of the head are suggestive that Eryops used stealth for hunting, much like a modern crocodile, and sat quietly in the water waiting for prey with only its eyes and nostrils visible above the water.

It had a stout body with very wide ribs, a strong spine, four short, strong legs, a short tail and a wide, elongated skull with many sharp teeth in large, strong jaws. Its teeth had enamel with a folded pattern. Eryops was about 5 feet (1.5 metres) long, one of the largest land animals of its time. It weighed about 200lbs. The skull of Eryops is proportionately large, being broad and flat and reaching lengths of 2 feet (60 cm).

Eryops was one of the largest land animals of its time, but the faster-moving Dimetrodon may have preyed upon it on land. The primitive shark Orthacanthus may have hunted it in the water.

Their body weight was not central over the limbs, but was transferred 90 degrees outward and down through the lower limbs, which contacted the ground. Most of the animal's strength was used to just elevate its body off the ground for walking, which was probably slow and difficult. With this sort of posture, only short, broad strides could be achieved. This has been confirmed by fossilized footprints found in Carboniferous rocks.

Eryops is an example of an animal that made successful adaptations in the movement from a water environment to a terrestrial one. It retained, and refined, most of the traits found in its fish ancestors. Sturdy limbs supported and transported its body while out of water. A thicker, stronger backbone prevented its body from sagging under its own weight. Also, by utilizing vestigial fish jaw bones, a rudimentary ear was developed, allowing Eryops to hear airborne sound.

Eryops fossils have been found in Texas, USA, North America. Eryops was named by E. D. Cope in 1887.

Scientific Classification:

Kingdom: Animalia

Phylum: Chordata

Class: Amphibia

Order: Temnospondyli

Suborder: Euskelia

Superfamily: Eryopoidea

Family: Eryopidae

Genus: Eryops

Species: E. megacephalus