Chapter 2: Saurocrocomorphs
For millions of years the Croodaceous skull island has been a paradise for almost every life form that journey towards it from the various land bridges, however there is a small problem with this paradise. As the island grew bigger and bigger over the millions of years that it has been in existence some parts of it started to become unstable and had starting sinking into the sea. During the great Cretaceous period this wasn't much of a problem for the wildlife of the various Paleozoic eras, but as the inhabitants of the Mesozoic eras, started converging onto the island, this was starting to become less and less space. At first this was only a minor inconvenience for most of the new saurian arrivals, especially for the crocodilians, but as centuries passed the island started sinking more and more, resulting in more and more lakes, rivers and swamps, and that was becoming a problem. Various predators have evolved in the lakes, and rivers in the island and that's not even getting to the creatures in the ocean surrounding the island, it would be a hazard just to get around the corner somewhere without getting into a fight for survival. To adapt to this various creatures on the island started to slowly evolve amphibious characteristics to survive on the drowning island, some subtle and some extreme. However some species have evolved a way to take advantage of the growing semi aquatic world, and put things in their favor.
At some point in the 65 million years of evolution several Species of the Croodaceous Skull Island large theropods evolved crocodilians esque characteristics such as armor, teeth and swimming capabilities to become stronger, deadlier and more efficient hunters. Most of these new life forms consists of some if not every member of the still remaining theropod species, with various developments, with even the most terrestrial species still being able to swim with the grace of a crocodile. The specific reasons for this change for this specific group of animals is still unknown, maybe from being forced into an area they need to live in, but had to adapt to survive in, to chase after swimming prey, or prey that has also adapted an amphibious lifestyle or just to develop stronger armor and teeth. Only the basics are currently known, but it is still enough to make them some of the most successful group of predators on the island. At first this was extremely puzzling to modern paleontologists, since it is common knowledge that most theropods are the ancestors of modern birds, however it was deduced that this was an example of convergent evolution since both crocodilians and dinosaurs have the same ancestor, and a necessary adaption due to the environment they live in.