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Cave CrocodileA fossil crocodile snout juts from the bottom of a freshwater cave—one of many incredibly well-preserved fossils recently discovered in the Dominican Republic. (Watch video of the Dominican Republic cave dive.)The toothy jaw belongs to a nearly complete crocodile skeleton found buried in the silt. Scientists are still working to determine the animal's exact age and species, but the team thinks it's been lying in the cave's cold water for millennia and may belong to a group that's now extinct.In addition to the fossil croc, divers searching for ancient monkey bones found the remains of sloths, bats, birds, and other creatures lining the floors of the flooded caves."You often find paleontology sites where specimens are buried by tons of rock," said team leader Alfred Rosenberger, an anthropologist with Brooklyn College in New York. "They are affected by erosion and weather, and there is an entire process from death of the animal to eventual recovery where a lot of things can be damaged."In the underwater caves, though, "we are finding almost pristine material."—Brian Handwerk

Photograph courtesy Phillip Lehman