NEW YORK (CBSNewYork/AP) — New York’s American Museum of Natural History has an intriguing proposition: Bring in anything you have and don’t know what it is, and scientists will try to identify it.

Saturday was what the museum calls its annual “Identification Day” devoted to helping people break the mystery of their specimens such as shells, rocks, insects, feathers and bones — or whatever.

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The big score of the day came from Bridget Cady, WCBS 880’s Kelly Waldron reported.

“I found a piece of a Mesosaurus jaw,” she said.

It’s millions of years old. 

“I was here two years ago, and I found coprolite, which is prehistoric dinosaur poop,” Cady said.

She knew she was heading in the right direction in her quest for fossils.

“I found a couple other things — Corolla crabs, which are prehistoric blue claw crabs,” she said.

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So what exactly is a Mesosaurus?

“Have you seen Jurassic World? You know the very end of the movie when that monster jumps out of the water and eats a T-rex? That is a Mesosaurus,” Cady said.

The explorations took place in the Theodore Roosevelt Memorial Hall, named after the U.S. president with a passion for natural history.

Items identified in previous years have included a whale jawbone, a fossilized giraffe vertebra, and a 5,000-year-old stone spear-point from Morocco.

Visitors were also invited to explore rarely seen objects from the museum’s collections.

For more information on today’s Identification Day, CLICK HERE.

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(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)