Dinosaur Evolved Opposable Fingers 75 Million Years Ago

Bambiraptor evolved opposable fingers 75 million years ago, long before primates developed opposable thumbs.

Phil Senter at Lamar State College in Orange, Texas, US, who made the discovery, said the arm movement would have allowed the Bambiraptor to hold prey with both arms, or use its long arms to bring objects to its mouth.

But even more surprising was that it was possible for the dinosaur to put the tips of the outer two of its three fingers together, the way a human is able to touch the tip of the thumb to the tip of the third finger - a trait not known in any other dinosaur.

Working with models of the bones, Senter found that while most predatory dinosaurs grabbed prey with their mouths, Bambiraptor might have grabbed prey like a frog or small mammal with one hand.

“Sharp claws on its fingertips could impale prey from both sides and prevent it from escaping. Caterpillars would be perfect to grab between claws and drop into its mouth,” New Scientist quoted Senter as saying.

Dromeosaurs, or flying dinosaurs were close relatives of birds, and the most primitive one yet found, Microraptor, had long feathers on both arms and legs.