Dinosaurs in Our Backyard - Cast of Characters

Large theropod similar to Acrocanthosaurus (THAIR-oh-pod; ACK-roh-KAN-thoh-SORE-us)

An artist's reconstruction of a large theropod. This short-armed carnivore is shown eating a nodosaur. Its tail is held out straight behind for balance.

Click to zoom.

A few teeth and bones from giant meat-eating theropod dinosaurs have been found in the Washington, D.C. area. The teeth have distinctive blunt serrations along "knife-blade" edges that suggest they came from a relative of Acrocanthosaurus, a huge predator over 11 meters (36 feet) long found in similar-aged rocks in Texas and Oklahoma. The few bones we have, including a large toe bone, are also similar to those of Acrocanthosaurus, but we do not have enough bones to be certain it was the same species. This animal's large size likely made it the dominant carnivore in this ecosystem.

A large serrated tooth that may have belonged to an Acrocanthosaurus. It is five and a half centimeters (about two inches) long.

Large theropod tooth. Notice the serrated edge - perfect for slicing meat. Click to zoom.

A toe bone from a very large theropod. There is a round indentation pn the side of the bone where ligaments would have attached.

This toe bone is from a very large theropod, probably a species similar to Acrocanthosaurus. Click to zoom.

Would you like to know more about:

How do paleontologists identify dinosaur teeth? Watch a video.
How we know what dinosaurs and other extinct animals ate? Watch a video and read about fossil evidence of diet.