The material on the covers of books from a French abbey was too hairy to have come from calves or other local mammals. Researchers identified its more distant origin.

Researchers found crocodilians, bats, raccoons and other creatures prowling a Florida town’s storm drains, “like something out of ‘Teenage Mutant Ninja Turtles,’” one said.

The long structures seen in manta rays and their relatives function as an early warning system, rather than a defensive weapon.