A new study conducted by the University of Bristol has found crocodiles underwent ‘snappy evolution’ making them flourish on land and in the oceans. While modern crocodiles are predators living in rivers, lakes and wetlands preying on fish, reptiles and birds, a new research published in the journal Proceedings of the Royal Societyreveals ancient crocodiles were much more varied because of rapid evolution. The mystery behind –why did the crocodiles survive the asteroid strike that wiped out dinosaurs 66 million years ago — is believed to be solved with this study, stating that some crocodiles were adapted to living in oceans like dolphins and others lived on the land as fast-moving plant-eaters.
Researchers from the University of Bristol and Harvard University studied over 200 skulls and jaws, as well as fossils from the 230-million-year history of crocodiles and their extinct relatives. Shape variations of the skulls and jaws among different species were studied to analyse how fast crocodile groups changed with time.
The findings reveal that some extinct crocodile groups, including dolphin-like thalattosuchians and land-dwelling notosuchians, evolved rapidly over millions of years, undergoing many changes to their skulls and jaws becoming mammal-like.
It also suggests that crocodiles, alligators, gharials, the only living crocodilians, have evolved steadily over the last 80 million years, and are not ‘living fossils’ as there is ‘no evidence for a slow-down in their evolution.’
Dr Stephenie Pierce, Associate Professor of Organismic and Evolution Biology at Harvard University, explained ancient crocodiles came in a “drizzlingly array of farms” and “were adapted to running on land, swimming in the water, snapping fish and even chewing plants.”
She told Daily Mail that the study shows “extinct crocodiles rapidly thrive and dominate novel ecological niches over many millions of years.”
Dr Tom Stubbs, who led the study, told that crocodiles and their ancestors are an “incredible group for understanding the rise and fall of biodiversity.” He added, today there are 26 crocodile species, most of which look similar, but there are “hundreds of fossil species with spectacular variation, particularly in their feeding apparatus.”
Professor Michael Benton, who also contributed to the study, said that it’s not clear why modern crocodiles are “so limited in their adaptations.” He explains their “fossil records show their amazing capabilities, including large numbers of species in the oceans and on land.”