The fine claw of Ophiacodon retroversa, Lower Permian age, collected in Jefferson County, Oklahoma. Ophiacodon belonged to the family Ophiacondontidae; which existed in the Late Carboniferous to early Perminian. There is some debate as to how these ancient reptiles lived. Some say they survived on land but other claim they were semi aquatic. Arguments for a semi aquatic mode of life have been influenced by the narrow heads, small teeth and broad claws of Ophiacodon, as evidenced by our specimens. These fine claws are approximately 0.6 to 0.9 cm long and 0.4 cm wide and come in a small plastic bag with an information label.