Plesiosaurus tooth in matrix

This Plesiosaurus mauritanicus tooth is still embedded in its original matrix of sandstone. The Plesiosaur  was a large aquatic carnivorous reptile appearing at the start of the Jurassic period. The specimen comes from the Upper Cretaceous of the Khouribga phosphates in Morocco.

The tooth measures 2.35 inches long and 0.65 inches wide at its base. The matrix is comprised of a fine/medium coarseness of sandstone containing pieces of unidentified bone. The entire specimen, tooth and matrix, measures 3.2 inches long, 2.65 inches wide and 1.25 inches high.