From end to end, its forelimbs alone measured an incredible 2.4 meters long and were tipped with big, comma-shaped claws. But other than its bizarre arms, very little material from this dinosaur had been found: no skull, no feet, almost...

"When it comes to extinct creatures like dinosaurs, it can be tough to know for sure what they actually ate. And we’d like to know because what an animal eats tells you a lot about it. But every now and then, the fossil record gives us a...