Gallimimus

Gallimimus was a fast-moving dinosaur that lived in prehistoric Asia.

This dinosaur and its relatives are sometimes called ostrich dinosaurs due to their appearance. Gallimimus was one of the biggest, growing to be twice as tall as an adult human.

The name Gallimimus means 'chicken mimic' and comes from the fact its neck bones look like those of chickens.

Scientists are confident Gallimimus had feathers. There's no direct evidence, but Ornithomimus and other closely related dinosaurs had them.

Experts estimate that Gallimimus could run at speeds of 47-55 kilometres per hour - more than twice as fast as a fit human.

Gallimimus' impressive sprinting power was probably its main method of keeping itself safe from predators.

But it was likely slower than a modern ostrich, which can run at up to 70 kilometres per hour. An ostrich is much smaller than Gallimimus, and the dinosaur's arms and tail would have added to its weight.

The movie Jurassic Park shows a flock of Gallimimus stampeding together. Polish scientist Zofia Kielan-Jaworowska, who discovered the first ever Gallimimus skeleton, called it a "beautiful scene". But did this happen in real life?

It's possible, although nobody knows for sure.

There's some evidence Gallimimus lived in groups. A single bone bed contained multiple skeletons, suggesting they died together.

Gallimimus had a toothless beak a bit like that of modern ducks and geese. This suggests it may have eaten small animals and insects.

Some scientists think Gallimimus might have used its beak to filter food from water or mud, like some ducks do. Birds that feed in this way have similar structures in their beaks to Gallimimus.

However, other researchers say these structures were more like the ridges in the mouths of herbivorous animals used to cut and eat tough plants.

The most likely answer is that Gallimimus was an omnivore, meaning it ate both plants and animals depending on what was available.

While Gallimimus looked somewhat ostrich-like, it wasn't closely related.

Ostriches and other modern birds evolved from a different branch of the dinosaur family tree known as the maniraptorans.

This group includes many feathered and bird-like dinosaurs, such as Velociraptor and Archaeopteryx. So, the ostrich-like nature of Gallimimus is a coincidence.

When two unrelated animals happen to evolve similar traits, it's called convergent evolution.

This might happen because the two animals live in the same type of environment or need to do similar things to survive, so they end up evolving along the same lines.

Although the film Jurassic Park depicts a Tyrannosaurus attacking Gallimimus, these two dinosaurs would never have met in real life.

Gallimimus lived in Asia, while T. rex lived in North America.

But a T. rex relative - another very large tyrannosaur called Tarbosaurus - did live in Late Cretaceous Mongolia and may well have hunted Gallimimus.

Although there's no conclusive evidence of a tyrannosaur preying on Gallimimus, Tarbosaurus bite marks have been found on a related dinosaur - the hump-backed herbivore Deinocheirus.