Edaphosaurus cruciger

Edaphosaurus is a genus of extinct edaphosaurid synapsid that lived in what is now North America and Europe around 303.4 to 272.5 million years ago, during the late Carboniferous to early Permian periods. The American paleontologist Edward Drinker Cope first described Edaphosaurus in 1882, naming it for the "dental pavement" on both the upper and lower jaws, from the Greek edaphos/εδαφος and σαυρος/sauros.
 * The name Edaphosaurus, meant as "pavement lizard", is often translated inaccurately as "earth lizard", "ground lizard", or "foundation lizard" based on other meanings for the Greek edaphos, such as "soil, earth, ground, land, base" used in Neo-Latin scientific nomenclature. However, older names in paleontology, such as Edaphodon Buckland, 1838 "pavement tooth", match Cope's clearly intended meaning "pavement" for Greek edaphos in reference to the animal's teeth.
 * Edaphosaurus species measured from 0.5 metres to almost 3.5 metres in length and weighed over 300 kilograms. In keeping with the tiny head, the cervical vertebrae are reduced in length, while the dorsal vertebrae are massive, the tail is deep, the limbs are short and robust and the ribs form a wide ribcage. Like most herbivores, Edaphosaurus would have had a capacious gut and symbiotic bacteria to aid in the breakdown of cellulose and other indigestable plant material.


 * Edward Drinker Cope named and described Edaphosaurus in 1882, based on a crushed skull and a left lower jaw from the Texas Red Beds. He noted in particular the "dense body of teeth" on both the upper and lower jaws, and used the term "dental pavement" in a table in his description. The type species name pogonias means "bearded" in Greek, referring to the enlarged inward sloping chin on the lower jaw. Cope classified Edaphosaurus as a member of his Pelycosauria and created the new family Edaphosauridae.
 * Other proposed species of Edaphosaurus have been based on more fragmentary material that cannot be rigorously diagnosed to a genus/species level, but which may nonetheless represent edaphosaurids. The nominal species Naosaurus raymondi was assigned to Edaphosaurus by Romer and Price, but Modesto and Reisz designated it a nomen vanum, and Spindler considered it probably referable to Ianthasaurus due to its age and stratigraphy.