This young adult Edmontosaurus appears to have survived an attack! The fossil, field named “Survey”, was more than 75% complete, while the skull was nearly 100%, including all four sets of teeth batteries. On the right dentary (lower jaw) are deep gouges and shallower ones on the left. Close examination suggests the bite marks may have begun to heal. The original specimen is now at the Fukui Prefectoral Museum in Japan.

Some estimates put the largest adults at nearly 49 ft long, weighing 10 tons. Additionally, hadrosaurs, duck-like billed dinosaurs like Edmontosaurus, had more teeth than any other known animal, numbering more than 1,200. Latest studies suggest hadrosaurs had highly efficient chewing, moving their lower jaw up and down with a forward and backward motion; they could not move their jaw side-to-side like a cow.