Nicholas Judson - Tyrannosaurus rex, 2007

Tyrannosaurus rex, 2007

Pencil on paper drawing. 7" x 5". Dinosaur skeleton displayed at the National Museum of Natural History, Washington, DC.

Greeting card reproductions of this image are available for purchase.

Original pencil on paper drawing: private collector, not available for purchase.

Tyrannosaurus rex was one of the largest land-based carnivorous animals ever. The largest reported skeleton found so far was 13 feet tall, 42 feet long, and in life weighed an estimated 7 tons. T. rex flourished through a span of about three million years at the end of the Cretaceous Period (about 67 million years ago), in what is now western North America. The "tyrant lizard king" walked on two legs, using its long tail to counterbalance its massive torso and skull. The skull, at up to 5 feet long, enabled a ferociously powerful bite with teeth that were replaced throughout its life, similar to what happens today with sharks and their teeth. Unlike sharks, however, T. rex teeth were oval in cross-section, not bladelike. Healed wounds inflicted by T. rex teeth have been found on at least one Triceratops fossil, lending credence to the idea that T. rex was a predator of Triceratops, although there is little other direct evidence.

Because of their size, large dinosaurs may have been limited in their ability to move quickly, so the question arises of how fast T. rex could have run to chase its prey, if at all. (The hard part would have been stopping 7 tons rapidly without damage.) Much like lions today, however, T. rex was certainly also a scavenger of dead animals. Although we can't know their feeding strategies, it is interesting to speculate: Did they hunt in packs, like lions and hyenas, or did they hunt alone, like crocodiles? Did individuals get slower as they grew older and larger, and therefore did their modes of hunting change? Did they live in a matriarchal society, like elephants do?

The Tyrannosaurus rex drawn here is on display at the Smithsonian Institution National Museum of Natural History, in Washington, DC.