The surface of the continents also looked different from the way it does today. For a start, what are now deserts -the Sahara, for example - weren't always barren sandy places, but were once rich with vegetation and vice versa.

However, most of the plants we know today simply weren't around during the Mesozoic era. There were no grasses, for instance, and flowering plants did not appear until the Cretaceous period. The main types of vegetation were ferns, cycads (palm-like trees), conifers and ginkgos (another kind of tree). But, by the end of the Cretaceous period, flowering plants were everywhere.

The temperature also changed during the Mesozoic era. During the Triassic period, it was generally warm everywhere -particularly near the centre of Pangea, which many palaeontologists believe was a desert. As the landmass broke apart, temperatures around the globe began to vary and the overall temperature dropped. Still, some estimates put the mid-Cretaceous temperatures at an average of 10°C (50°F) warmer than they are today.

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