A nice section of Triceratops frill from the Hell Creek Formation.
This is a nice piece with good surface detail (the small channels running over the surface would have once housed blood vessels which supplied blood to the frill). The light colouration on the reverse side is due to sun bleaching - this part of the frill was poking out of the ground and visible on the surface.
Size: 4.25 inches at longest length
Age: 65 Million Years
Locality: Powder River County, Montana (Hell Creek Formation)