An extinct species
Tyrannosaurus rex
Tyrannosaurus rex
The giant hunter closer to chickens than to Triceratops.
You and the tyrannosaurus rex last shared an ancestor about 320 million years ago (on 4 December, if life's history were one year).
This famous predator was a closer relative of a chicken than of Triceratops. It was a meat-eating dinosaur in the same broad group as living birds, so chickens, pigeons and hummingbirds are its distant cousins. Triceratops sat on a more distant branch of the dinosaur family.
It was about 12 metres long, as long as a school bus, and weighed about 6 to 8 tonnes, as heavy as a big African elephant or heavier. Its backbone stayed roughly horizontal, balanced by a long heavy tail. It had a huge head about 1.5 metres long with about 60 thick teeth, tiny arms about a metre long with two clawed fingers, and long powerful hind legs with bird-like feet.
It lived about 68 to 66 million years ago in what is now western North America, in warm forests, river valleys and open plains. It hunted live plant-eating dinosaurs and also fed on dead animals it found. It vanished about 66 million years ago when a giant space rock hit Earth near what is now Mexico.
Teenage growth spurt
Sue gained up to about 2 kilograms per day as a teenager and was fully grown at about 19 years old. Scientists read this from growth rings in bone, like tree rings. Sue lived to about 28, unusually old for its kind.
Slower than the films
It could not run as fast as films show. One recent estimate puts its top speed at only about 16 kilometres per hour, barely faster than a person. One study put its preferred walking pace at only about 5 kilometres per hour.
A keen nose and a crushing bite
It had large smell parts in the brain for a keen sense of smell. Its bite may have been as strong as the weight of about six tonnes, enough to punch through bone.