© J. Sibbick
Parasaurolophus.

Dinosaurs are amazing animals--and sometimes quite bizarre. Among the many different species of dinosaurs, we find all sorts of strange body parts. Plates of armor. Exceptionally large or oddly shaped heads. Bony plates sticking out of the back--and bony horns sticking out of the front.

Researchers have long wondered about the purpose of such peculiar features. Perhaps some served to protect the animal in battle. Others might have helped a dinosaur stay cool. More recently, scientists have come to another conclusion: Some of these features were likely used by dinosaurs in the competition for mates or to recognize members of their own species.

Look closely at a skull

Imagine that your skull has an extra layer of solid bone on top. Dome-headed dinosaurs had large, rounded heads thanks to a thick layer of bone. How did these animals use their domes? Scientists are investigating whether the animals used their heads for fighting or flirting.