Giant dinosaurs, such as sauropods, avoided the tropics for up to 30 million years due to the harsh and fluctuating climate, according to a study by researchers at the University of Southampton. The study, which analyzed rocks deposited by rivers and streams between 205 million and 215 million years ago, found that plant fossils hinted at repeated sudden changes in climate, while fossil charcoal suggested that raging wildfires every few dozen years could reach temperatures of up to about 1,100 degrees Fahrenheit. These conditions would have made it difficult for abundant vegetation to grow and survive, preventing giant herbivores from invading the region.