Despite being separated by around 300 million years of evolution, Australian researchers at Monash University and the University of Newcastle have found that toothed whales and crocodiles have very similar shaped skulls.
"Even though these species are very distantly related, they have evolved with a similar range of skull shapes," author of the study Matthew McCurry told Xinhua on Wednesday.
"Dolphins feed on wide variety of things like agile fish and sometimes much larger prey. Crocodiles also feed on a wide variety of prey and what we found is that the crocodiles that feed on agile fish have developed very similar skull shapes to dolphins."
It's believed that having a thinner, longer snout is highly advantages for both crocodilians and toothed whales trying to catch small fish.
The findings are in contrast with the previously held consensus that it may have been the shallow waters which contributed to the shape of the skull.
"Our results suggest the remarkable similarity between some crocodilians and toothed whales is driven by what they eat rather than where they live," he said.
To compile this study, McCurry travelled to a number of museums in Australia and the United States with a 3D laser scanner to digitally capture images of skulls onto a computer where they could be modelled and examined in further detail.
"Now that we have established that animals that feed on certain types of prey have similar shapes skulls, we can look at fossils and if they're that shape we can say with certainty, what the diet of the extinct species was," he said.