Once upon a time, back in the Early Jurassic to the Early Cretaceous period, there was a group of ancient crocodile species that use to live on the ground. Thalattosuchian was a marine crocodylomorph, the ancient and extinct ancestor of the modern crocodile. Its cosmopolitan distribution says the story of an extended range across most of the world, where the habitats were appropriate.
So, Thalattosuchian used to live on the ground. At some point, the evolution code inside it whispered to it to get into the water and leave the land-living shape behind. And so, it did. Its limbs became flippers. Its body became streamlined. It has grown a fluked tail. All of that to help it move through the new habitat that was no longer submitted to the same gravity as the land.
The new study on the ancient crocodile behavior
Recently, scientists from the University of Edinburgh came with new understandings of Thalattosuchian evolution into a marine species. The adaptation of a less visible part of their body, but equally important if it were to survive in the new environment: the inner ear, which is responsible for balance and equilibrium in that gravity-free home called water.
The Cat-scans of the fossil skulls showed evidence of three looping semicircular canals. More than a dozen skulls’ vestibular system of the inner ear were examined. It seems that the ear canal of the Thalattosuchian became fatter and smaller with time. As if the Thalattosuchian was mimicking dolphins and whales, which did that at the same time.
“The [ancient crocodile] developed unusual inner ears after modifying their skeletons to become better swimmers. Whales also changed their ears in a similar way but did it soon after entering the water. It seems like the crocs and whales took similar but different evolutionary routes from land to water,” said Dr. Steve Brusatte, from the University of Edinburgh’s school of geosciences, and senior author on the study, as reported.