(Top to bottom):  Gavials gangeticus; Inia geoffrensis
(Top to bottom): Matěj Baťha /Wikimedia Commons; Nortondefeis/Wikimedia Commons

Read our COVID-19 research and news.

Can you spot the similarities?

Compare the head of a gharial crocodile (top) to an Amazon river dolphin (bottom), and you might spot some striking similarities. At least scientists have. After analyzing the skull and jaw shapes of more than 75 living species of crocodilians and toothed whales, researchers have found that these creatures share a broad yet remarkably similar range of skull and snout shapes—despite being separated by nearly 300 million years of evolution. Overall, predators with wide snouts and relatively large, robust skulls, such as crocodiles and orcas, are built to resist the stresses of grabbing and holding sizable, struggling prey, the team reports today in the Proceedings of the Royal Society B. But aquatic mammals and reptiles that have long, slim snouts are relatively ill equipped to tackle large prey, and instead predominantly dine on small fish. Results of the analysis may make it much easier for paleontologists to infer the prey preferences and feeding styles of ancient aquatic creatures, especially if they have similar skull proportions to modern-day predators.