What is NOT a dinosaur? (In The Air)

Dinosaurs were not the only animals around during the Mesozoic, but may people think so. Of course, there were also insects, lizards, amphibians, and later, birds. Dinosaurs are technically classified as terrestrial (living on land) animals. If they flew or swam, they aren't considered dinosaurs. Here we will look at some of the other types of prehistoric, and now extinct, animals living during the reign of the dinosaurs.

Let's start in the air. One group of animals that you see in lots of dinosaur drawings, paintings, and movies, is pterosaurs, which means "winged lizard". These were the great flying reptiles. Firstly, lets get the pronunciation out of the way. It's pronounced "ter-ro-sore". The "P" is silent. My guess, is that it was put there so 1st graders would learn how to pronounce it correctly, while their parents struggled with it, therefore, making the 1st grader somewhat superior to their parent, at least in one aspect of life.

Pterosaurs came into being towards the end of the Triassic period and flourished on through to the end of the Cretaceous. As it seems with most animals, they started out quite small and grew to huge B-52 size majestic flyers.

Pterosaurs formed two main groups: ones with long tails and ones with short tails. The long tailed pterosaurs evolved first. The long-tailed rhamphorhynchoids lasted from the late Triassic period until the late Jurassic. Then the short-tailed pterodactyl took over into the late Cretaceous. The most notable differences between the two groups are in appearance. The rhamphorhynchoids were quite small, had shorter necks and heads and a mouth full of teeth, some having quite bizarre dental work! Pterodactyls were all toothless, had short necks and sported elaborate head crests that might have been brightly colored in life.These groups are considered somewhat "informal" in the paleontological world and many scientists break the pterosaurs into more specific categories.

So, how did these buggers get around? Well, they flew, of course? And glided...and walked. At first, most scientists assumed they were purely gliders. They would need tall trees or cliffs to start from, then glide down on warm air currents. While this may be true, especially for pterosaurs that lived near the sea, they could also fly. Probably not as well as birds or bats, but they could do it. They had adaptations like hollow bones and powerful muscles built around a breast bone important for the stamina needed for flight.

Pterosaur remains have mostly been found in marine deposits, meaning these particular species were living in a marine environment. Perhaps soaring over seas or lakes to eat fish as some modern birds of pray do today. Just because their remains have not been found in many different environments, does not mean they did not live elsewhere. Between the physical structure of these animals and the fossil preserving aspects of other area such as deserts or forests, dead pterosaurs, perhaps, just didn't fossilize in those areas. It usually takes a pretty specific set of circumstances to preserve an animal in a fossilized state.

So, while dinosaurs roamed the land, these guys were flying overhead and probably, in some instances, battling carnivores for carcasses. Also, at the same time, there was another group of "non dinosaurs" thriving, but they were in the sea. Lets take a look at the life and times of marine reptiles next.

Next-Marine Reptiles.