Prehistoric climate change affected global spread of dinosaurs
DOI: 10.1063/PT.5.028961
Nature : Sedimentary rock from the late Triassic period suggests that extreme climate change in Earth’s lower latitudes prevented large dinosaurs from living there for some 30 million years. Jessica Whiteside of the University of Southampton in the UK and colleagues reconstructed early climate conditions by studying the amount of carbon-13 and fossil pollen trapped in the rock. Not only did the US Southwest’s paleoclimate vary between extremes of very wet and very dry, but atmospheric carbon dioxide levels soared to 2400 parts per million, much higher than the current level of 400 ppm. The region also experienced some fairly severe wildfires as evidenced by pockets of fossilized charcoal. As a result, reptiles, which are smaller and needed less food, predominated.
