One of my friends, followers, readers and fellow bloggers, Naveed, has wanted me to a special Fossil Fact just for him. As I've ran out of ideas for facts, I thought of an idea!!! Why not get my readers involved? It was ingeneous and whaddya know it works. Well, as well as it can for Naveed to give me a suggestion. (No offense, dude.) He's a blogger and follows my blog and is fan of it. (Yay, my second fan!!) Anyway, you'd expect him to. He's a blogger. Now....enough with my rambling.....let's get the show on the road and on the Fact.
The Triassic: end of the Archosaurs and dawn of the Dinosaurs (Part One of the Mesozoic)
First off Naveed, Dinosaurs weren't the only animals that populated the Earth during this period. In fact, Dinosaurs didn't appear until the Late Triassic. The dominant land animals were huge reptiles designated Archosaurs by Paleontologists. These HUGE reptiles were bigger and different than the reptiles that inhabit the Earth today. (Probably because of the greater Oxygen levels in the atmosphere than today.)
Now, for the continents. The world is unrecognizeable. All the land masses are smashed together into one big Supercontinent called Pangaea. It'll be about 250 million years until the giant land mass crumbles like a cookie into the seven continents that we know today. This causes the seasons to be about the same nearly everywhere. It was on Pangaea that evolution spawned a new kind of reptile. One that would become one of evolution's greatest success stories: The Dinosaur.
Now, during the Late Triassic, the earth was still full of huge reptiles that still had the primitive leg design. Their legs were sprawled out away from their hips like modern reptiles. The bully on the block was one mean and nasty Archosaur: Postosuchus ("post crocodile"). This guy had a huge head that was filled with teeth that were like steak knives that were perfect taking a big chunk out of it's horned-faced ugly herbivorous neighbors the Placerias. It wasn't very fast as it had the primitive reptilian hip/leg design. However, it needn't be, it's prey couldn't run if their lives depended on it (and it usually did.) The only thing Postosuchus had to worry about was another Postosuchus. That depended on how big the other one was and how loud it's roar was. (Remember, this is all speculation and I got this information from Walking with Dinosaurs....well...these guys introduced me to these Archosaurs.)
On with the early dinosaurs. Well, the one I know the most about is Coelophysis. This theropod (simply, paleontologists designation for dinosaurian carnivores) was light weight, built for speed, and it's bones were hollow like a bird's, yet, strong. It's neck vertebrae was shaped into an S which was perfect for striking quickly at it's prey. It, presumably, hunted in packs or some sort of social group with some sort of social structure. One thing we do know, is that it was a cannibal that occasionally ate it's own young in harsh conditions. The reason? Probably, to avoid turning on each other and risking injury with a lack of food. Smart move, considering, they could spawn more young if the adults survived. The reasonable time for cannibalism would be during severe dry seasons with severe drought and severe scarcity of food. ( One neighbor that I forgot to mention during the Triassic were the mammal-like reptiles that gave rise to the true mammals.) Sadly, it didn't save them from extinction in the Jurassic period.