Diplocaulus magnicornis Cope
Amphibian
Early Permian
Ryan Formation
Jefferson County, Oklahoma, USA

Excellent ornamented skull fragment. Avg. 0.5 inch.

Diplocaulus is a genus of fully-aquatic amphibians (Order Nectridea) that appeared during the Late Pennsylvanian and lived across the Permian.  It’s known primarily from sites in the western U.S. (Oklahoma, Texas, and New Mexico).  Other related genera are known from Europe and North Africa.

If you’re a kid from the 70’s, you’ll remember Diplocaulus even if you forgot the name.  It’s that boomerang-head amphibian from your dinosaur books.  This is a good companion specimen if you already have a jaw section and couple of bones from this animal.