During the early Cretaceous, there were two large continents, Gondwana to the south (comprising South America, Africa, peninsular India, Australia and Antarctica) and Laurasia to the north (comprising North America, Europe and Asia).
By the end of the period, these vast landmasses had sub-divided and moved much closer to their present positions. Australia was still connected to Antarctica, though, and India had not yet joined Asia. Overall, it was one of the warmest times in Earth's history, except for the polar latitudes, where scientists believe temperatures dropped below freezing during winter.
If there's one dinosaur that everyone's heard of, it's Tyrannosaurus rex ("tyrant lizard king"). This terrifying predator evolved during the late Cretaceous and grew to 12 metres. It weighed around 5 tonnes and could open its massive jaws an eye-watering 1 metre wide.
Their strong teeth, weren't just capable of ripping flesh. They could crunch through bone, too. But Tyrannosaurus wasn't all brute force. It had acute, binocular eyesight, ultra-sensitive hearing and a highly developed sense of smell.
Compared to Tyrannosaurus, Velociraptor ("quick plunderer") was very much a lightweight at just 1.8 metres and 7kg - 15kg. But what Velociraptor lacked in size it made up for in ferocity and killing efficiency.
Velociraptor could possibly reach speeds of 64kph, using its stiff tail as a counterbalance on tight turns. In addition to a mouthful of razor-sharp teeth, Velociraptor had huge claws on its feet and hands. It used these to climb up larger prey. As if one Velociraptor on its own wasn't enough, these vicious late Cretaceous killers hunted in packs.
Triceratops ("three-horned face") is the most famous of the horned dinosaurs. This late Cretaceous animal grew to around 9 metres and weighed up to 10 tonnes. As well as three deadly horns, Triceratops had an impressive bony frill behind its head. Palaeontologists believe this could have been used in courtship. It could have also been used in ritual combat with rivals, like rutting in deer. Triceratops was a herbivore. Its jaws ended in a beak that would have helped it gather tough vegetation.
Pterosaurs, flying reptiles with wingspans of up to 12 metres, had once been numerous but were on the decline during the late Cretaceous. Their place was being taken by direct descendents of dinosaurs, the birds.
Birds had evolved from the theropod group of dinosaurs, which included bipedal predators such as Velociraptor and Tyrannosaurus rex. By the late Cretaceous, birds were widespread in forests and mudflats. Some resembled modern birds, such as curlews and sandpipers. There was even a forerunner of today's parrot family.
We don't know for sure what caused it but at the end of the Cretaceous there was a mass extinction in marine and terrestrial life. Other life-forms, including reptiles and mammals, survived but dinosaurs, except for birds, of course, became extinct.
Some scientists believe that an increase in volcanic activity, together with the effects of the shifting continents, caused profound climate change on Earth. Another theory is that a massive extraterrestrial object hit the planet, perhaps an asteroid crashing into Chicxulub in Mexico, throwing up a huge dust cloud that obscured the sun, triggering climatic changes. Whatever the explanation, the age of the dinosaur was over.
Quick Dinosaur Facts
Tyrannosaurus rex's arms were thought to be weak and useless. Now, palaeontologists believe there's evidence that these arms were strong, with nearly opposable fingers. No one's sure what T. rex used his strong little arms for, though!
Tyrannosaurus rex probably didn't run, it would have been too heavy. However, there is a suggestion that Triceratops may have been able to gallop like a rhinoceros.
Quetzalcoatlus was the largest animal to ever fly with a wingspan of up to 12 metres.
Much of the evidence on the diet of dinosaurs comes from the study of their fossilised dung, called coprolites, or taking data from fossilised trackways.
The Velociraptors in Jurassic Park were portrayed at more than twice their actual size, and resembled a dinosaur more like the related Deinonychus. They also would have been covered in feathers.