The tropics are known to have erratic weather patterns, the most commonly knows on which are tropical cyclones. Giant dinosaurs in the past avoided the tropics because of these reasons, according to researchers. An example are the sauropods (gigantic long-necked, long-tailed, vegetarian dinosaurs). These dinosaurs were dominant in the higher latitudes, but there were very few in the lower altitudes near the equator.
Jessica Whiteside and some investigators from the University of Southampton have been studying rock deposits by streams and rivers for nine years. They are interested in rocks from 205 to 215 million years ago, from the late Triassic period, a period where all the land masses of the world were still on one big landmass known as Pangea. However, dinosaurs weren’t too common in the fossil finds. They were outnumbered by the pseudosuchians, a reptile ancestor that turned into modern day crocodiles and alligators.
From analyzing the plant fossils, the researchers theorized frequent and sudden changes in climate. Also, the rise and fall of carbon isotope levels indicated the same pattern applying to the vegetation in the area, owing to the fluctuating rainfall. Charcoal fossils also suggested that wildfires that happened every dozen years in the area would reach about 1,100 degrees Fahrenheit. These frequent changes would have made the area less than ideal for herbivores.