There was a different Peru before the Amazon River came into existence. The Peruvians then were not humans but 7 species of crocs. Yes, they the 4 legged giant lizards, the type of neighbors which you don’t want to have living next to you
Just imagine what it was in the Amazon before. These crocs live in harmony. They are civil to each other and they fed on foods which are much smaller than pigs, chickens or whatever happens that crosses their way.
With the coming of Amazon River, they all but just vanished. Maybe a few was able to survive and stick around but the majority didn’t make it.
New study has it, in the proceedings of the Royal B, the humongous Amazon basin, before the formation of the Amazon River approximately 10.5 million years ago, were the favorite haunt of a variety of crocodiles. Since their diet is composed of clams and other small mollusks, there was no problem with them all living together. There are more foods that they can consume.
Out of the seven species which lived there, three of those discovered there beginning in 2002 were entirely new. The most important fossil was that of Gnatusuchus pebasensis. It has a short mouth formed like shovel with round teeth decorating it. You could imagine how it gobbled up the swamp shelled creatures and mud altogether.
There were species who feed on anything they could eat. The researchers were also able to find the first real caiman in fossilized form with its smooth front which are still in existence up to the present which still survive on fish and anything that happens to be within reaching distance of its snout.
But the mollusk eaters, their survival were also washed away. The river swept the mollusks out of their habitat living the croc eating mollusks starved to death.
The river at present is totally diverse and only three species were left, more so the caimans. They go from one habitat to the other which give them better survival rate.