Crocodiles, alligators, caimans, and gharials are in the spotlight in the American Museum of Natural History’s latest exhibition, “Crocs: Ancient Predators in a Modern World.” In addition to exploring the evolutionary history of these prehistoric-looking beasts, the exhibition tackles crocodilian myths, analyzes threats to their survival, and features live animals (including the adorable alligator hatchlings you can see on the live stream below). mental_floss attended a preview of the exhibition, which opens tomorrow; here are a few things we learned.
1. There were many, many prehistoric crocodylomorphs, and they were a diverse bunch. Some were entirely marine animals; others, like Hoplosuchus kayi, were small and lived entirely on land. But some were huge: One of the biggest, Sarcosuchus imperator, was at least 35 feet long, and T. rex bones have been found with teeth marks from Deinosuchus, a giant croc that lived 80 to 73 million years ago.
2. Their blood contains special proteins that help make crocs—which spend their time in swampy water—immune to things that cause infection. Needless to say, scientists are pretty interested in whether or not we could use those proteins in human medicine.
3. Want to tell alligators and crocodiles apart? Look at their teeth: When gators close their jaws, they have an overbite—only the top teeth are visible. Crocs have a much toothier close-jawed grin; their top and bottom teeth interlock.
4. Crocs make a wide range of noises, a behavior that begins before they even hatch. (Being noisy in the egg allows the babies to synchronize when they’ll hatch.)
5. Croc skin might look tough—and, OK, it is tough—but it’s also more sensitive than the human fingertip.
6. Saltwater crocodiles are the largest living crocodilians; they can tip the scales at 2000 pounds. Dwarf caimans, which can grow up to 5 feet long, are the smallest.
7. Even big crocs can vanish in under a foot of water.
8. Ever notice how crocodilians hang out in the Sun with their mouths open? Doing so helps them keep regulate brain temperature: Water in their mouths evaporates and keeps their brains cool even while the rest of their bodies get nice and toasty.
9. Crocs have a little something in common with cats: A layer in the eye called the tapetum that reflects light. It’s why both animals’ eyes glow at night when exposed to a flashlight.
10. Seven species of crocodilian are critically endangered thanks to things like hunting, pollution, and habitat loss.