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An Ischyrhiza tooth (Fossils of New Jersey)


Ischyrhiza (Greek for "root fish"); pronounced ISS-kee-REE-zah


Oceans worldwide

Historical Period:

Cretaceous (144-65 million years ago)

Size and Weight:

About 7 feet long and 200 pounds


Small marine organisms

Distinguishing Characteristics:

Slender build; long, saw-like snout


About Ischyrhiza:

One of the most common fossil sharks of the Western Interior Sea--the shallow body of water that covered much of the western United States during the Cretaceous period--Ischyrhiza was an ancestor of modern saw-toothed sharks, though its front teeth were less securely attached to its snout (which is why they're so widely available as collector's items). Unlike most other sharks, ancient or modern, Ischyrhiza fed not on fish, but on the worms and crustaceans it rousted up from the sea floor with its long, toothed snout.

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