Parasaurolophus walkeri, left lower jaw (juvenile) hadrosaur Pteranodon A definitive explanation for their

A definitive explanation for their mass extinction is yet to be agreed upon

Jefferson thought they were the claws of a giant cat

New Zealand

There are vertical and horizontal hangers on the back

Parasaurolophus walkeri, left lower jaw (juvenile) hadrosaur Pteranodon A definitive explanation for theirParasaurolophus was a long crested, duck billed (hadrosaur) dinosaur. Its extremely long, backwards leaning, hollow, bony crest was as bigger than the rest of its skull and may have been used to produce a low frequency, foghorn like sound, enhance its sense of smell, and or used in courtship displays. The Parasaurolophus' nostrils (at the end of its snout) went up through the crest and back down it, forming four tubes. The crest was up to 6 feet (1. 8