This tooth specimen is a Ginglymostoma moroccanum nurse shark tooth. The Ginglymostomatidae family gets its name from the Greek language, meaning hinge mouth. They were small bottom dwelling, nocturnal sharks which fed primarily on crustaceans, molluscs, and other fish.
The teeth of Ginglymostoma moroccanum are characterized as similar to Ginglymostoma angolense with the center point of the tooth being somewhat wider and more rounded than the teeth of Nebrius obliquus. It is narrower than the other two and has fewer serrations than either of the other two. The serrations fan out on both sides with the ribbing extending down to the root of the tooth. The size of the nurse shark teeth are measured by their width (which is usually the largest measurement of the tooth).
As with all shark teeth, species will vary with slight or minor variations in their teeth. In the teeth offered here the Genus is either Ginglymostoma or Nebrius. This is the only Ginglymostoma moroccanum that we have found to date. In any case they are fairly rare, making up only one in 2,000 to 4,000 (or more) compared to the quantity of other shark teeth that are found.
Kingdom: Animalia, Phylum: Chordata, Class: Chondrichthyes, Sub-class: Elasmobranchii, Order: Orectolobiformes, Family: Ginglymostomatidae, Genus: Ginglymostoma, Species: moroccanum.
Ginglymostoma moroccanum 
Quantity in Basket: None
Code: TMGM-101
Price: $50.00
Shipping Weight: 0.25 pounds
Time: Paleocene - Eocene - approximately 60-45 million years ago.
Location: Phosphate beds, Khourigba, Morocco.
Dimensions: 3/16"
Size is measured in width.