Armored Lizard Skull (Peltosaurus sp.) | South Dakota

Peltosaurus sp.

Oligocene

Brule Formation 

Pennington County, South Dakota 

Specimen approx. dimensions: 3" x 1.5" x 1"

Matrix approx. dimensions: 5.25" x 4.5" x 4.5"

The preservation on this piece is fantastic.  Its armor is well-pronounced.  The mouth, including teeth, eye sockets, and nostrils are all clearly visible. There is some minor restoration.

Peltosaurus is an extinct genus of anguid lizard from North America that lived from the Eocene to the Oligocene.  Peltosaurus belongs to the anguid subfamily Glyptosaurinae.  Glyptosaurines are known primarily for their osteoderms, scale-like pieces of bone that are embedded in their skin and cover most of their bodies.  The osteoderms of glyptosaurines are unusually complex, consisting of four distinct layers of bony tissue.  These tissues may have derived from both the dermis and the epidermis during embryonic development.  The tissue forming the outermost layer of glyptosaurine osteoderms is similar to tooth enamel and is called osteodermine.