Summary in Seconds: A new study suggests that dinosaurs may have first evolved in hot, low-latitude regions of ancient Gondwana – areas now part of the Amazon, Congo, and Sahara – much earlier than current fossils indicate. Using modeling to fill gaps in the fossil record, researchers propose that early dinosaurs were small, adaptable creatures that later rose to dominance after a mass extinction. Scientists May Finally Have the Answer The origins of dinosaurs – those iconic rulers of prehistoric Earth – have long intrigued scientists and fascinated the public. A new study, however, is challenging traditional assumptions and offering