3 2.2 Ichthyopterygian Paleobiology - Part 2

Paleontologists think that some ichthyosaurs weren’t just strong, efficient swimmers but also accomplished divers. Yet, most ichthyosaur fossils that we find are preserved in coastal environments. So, how did paleontologists come to the conclusion that some of these animals spent time diving? Check all the answers you think apply. A, They have big eyes to see in the dark. B, They have large tails to drive them down. C, They got the bends, like scuba divers. And or D, They had extra heavy bones to help them sink. Plenty of animals that live only at the surface of the water have large tails and many animals that dive have smaller tails than relatives that live on the surface. So B is not correct. Diving animals also do not tend to have heavier bones. Since being neutrally buoyant is more efficient. So D is not correct. Ichthyosaurs had some of the biggest eyes of any vertebrates which probably would have helped them to see in deep, dark water. So A is correct. Icthyosaurs also show evidence of a bone disease ca