1.18 inch Fossil Eagle Ray Tooth Plate (Myliobatis) from Sharktooth Hill, California

Myliobatis is a genus of eagle rays in the family Myliobatidae.

Myliobatis species can reach a width up to about 6 ft. Their bodies consist of a rhomboidal disc, wider than long, with one dorsal fin. The head is broad and short, with eyes and spiracles on the sides. The tail is slender, with one or two large spines at the base, without tail fin.

The teeth are arranged in the lower and upper jaws in flat tooth plates called pavement teeth, each consisting of about seven series of plates, which are used to crush clam shells and crustaceans.

Myliobatis species are ovoviviparous. Their gestation last about 6 months and a female produces four to seven embryos. Myliobatis species mainly feed on molluscs, bottom-living crustaceans, and small fishes.

Mylobatis species live in warm, shallow waters. Adults prefer sandy shores, while juveniles can usually be found offshore.

Sharktooth Hill is one of the most famous vertebrate fossil sites in the world - a place where roughly 125 species of sharks, bony fishes, sea mammals, sea turtles, marine crocodiles, birds and even land mammals have been found.

The fossils are concentrated in a rather narrow one-to four-foot thick layer in the Round Mountain Silt Member of the Middle Miocene Temblor Formation, which is exposed over several square miles in the rolling foothills of California's southern Sierra Nevada.

Since it’s discovery in 1853, the Sharktooth Hill area has yielded thousands of shark teeth, including the rare giant shark, Otodus Megalodon!