Eocene Green River Gar Jaw
Atractosteus atrox
Green River Formation
Middle Eocene
Lincoln County, Wyoming
This specimen is a lower jaw section from a very large individual. The jaw section is over 20 cm with formidable teeth. There is no repair or restoration.
Atractosteus atrox is only found in the Green River Formation as large individuals that range in size from 63 to 81 inches in total length. Smaller members of the species probably inhabited the tributaries of the fossil lake. The snout sports jaws lined with sharp pointed teeth and it has 12 tail-fin rays. The scales of A. atrox are more ornamented and it has more lateral-line scales, than other gars from the Green River Formation. This species is also rarer than other gars in the formation.