The Calvert Cliffs of Maryland are peaceful now, but during the Miocene period (between 5 and 23 million years ago), they were the underwater home of megalodon, the giant ancestor of the great white shark; of giant predatory rays; and prehistoric crocodiles of 30 feet in length. Marine fossils are easy to find at the cliffs, with a little digging or simply by walking the beach.
Instructions
1. Look on the beaches of Calvert Cliffs State Park, located between Routes 2 and 4 in southern Calvert County, Maryland. Wait for low tide, when more of the beach is exposed and sand and silt have been washed away to reveal fossils.
2. Walk along the exposed cliffs, looking for exposed fossils. If necessary, loosen rock and dirt with your trowel or rock hammer.
3. Look for shark teeth. Marine animals such as sharks and rays have cartilaginous skeletons, which usually rot away before they fossilize. But a shark's hard enamel teeth last for millennia. Look in particular for blackened, flat, triangular fossils. With luck you will find a megalodon tooth, which can be up to six inches long. More likely, according to the Maryland Geologic Survey, you will find the teeth of prehistoric tiger, mackerel, and hammerhead sharks, up to an inch long with the bony roots attached.
4. Look for the teeth of the prehistoric crocodile, Thecachampsa antique. Unlike shark teeth, these are conical, resembling a tusk. They range from light brown to red in color and are usually an inch or two inches (though four to five inches is possible).
5. Look for the teeth of marine mammals of the order Pinnipedia, which includes seals, walruses, whales, dolphins, and porpoises. These teeth are more apt to look like a human's tooth, in that they have two sections, the exposed tooth and the root. (A reptile's or shark's tooth is more likely to snap off from the root.) These teeth can range from ¼-inch to perhaps 2-inches long; they are usually quite dark in color, coffee brown to nearly black.
6. Look for the vertebrae and ribs of marine mammals (again, porpoises, whales, seals, and so on). Vertebrae are symmetrical in shape, usually a large, thick disk with a ring of bone attached for the nerve path. Ribs will resemble sticks or the fragments of a stick. They range in color from dirty bone to nut brown, depending upon the surrounding sediments.
Tags: Calvert Cliffs, Look teeth, marine mammals, range from, shark teeth, teeth prehistoric, These teeth
