Direct Evidence: T. rex Hunted and Consumed Edmontosaurus

Historically, the Tyrannosaurus rex has been depicted as a large and fearsome hunter. Recent scientific consensus indicates that T. rex was both an active predator and a scavenger. Its diet likely included plant-eating dinosaurs such as Triceratops and Edmontosaurus, with T. rex bite marks found on their bones supporting this. Direct evidence of T. rex hunting and feeding behavior is often challenging to obtain.

A recently published study by paleontologists John Scannella and Taia Wyenberg-Henzler focused on a nearly complete Edmontosaurus skull to gain insights into these behaviors.

The Edmontosaurus Skull: Compelling Evidence

This Edmontosaurus skull, discovered in 2005 in eastern Montana and now displayed at the Museum of the Rockies, presents compelling evidence. It features a partial tooth tip embedded directly through the snout into the nasal cavity, along with multiple bite marks on both sides of the skull.

The absence of healing around the embedded tooth suggests the injury occurred either post-mortem or very shortly before death.

CT scans confirm the tooth's precise position, indicating it likely broke off during a face-to-face encounter. The significant force required for the tooth to embed in bone, combined with the lack of healing, suggests the Edmontosaurus did not survive the attack.

Analysis of the tooth's serrations and size confirmed it belonged to an adult Tyrannosaurus, with an estimated skull length of about one meter. The presence of bite marks on the Edmontosaurus skull indicates that the animal was not only killed but also consumed by the Tyrannosaurus.

Behavioral Insights from Bite Marks

The location of the bite marks provides further behavioral information. On the Edmontosaurus skull, marks are found on the right side behind the eye and along the back third of the left lower jaw. These areas correspond to where major chewing muscles and substantial flesh are located in duck-billed dinosaurs.

Modern carnivores typically consume the fleshier parts of a carcass first, then proceed to areas with less flesh, like the skull. The fact that only the skull was preserved suggests the Tyrannosaurus likely removed most of the flesh from the carcass before burial.

This fossil provides rare direct evidence of a dinosaur being killed and eaten by a Tyrannosaurus, offering significant insights into the potential hunting behaviors of large carnivorous dinosaurs.