Scientists clarify origins of pterosaurs, the dinosaur era’s flying reptiles Scientists may have solved one of paleontology’s enduring mysteries — the evolutionary origins of the flying reptiles called pterosaurs that ruled the skies at the same time that dinosaurs dominated the land. Researchers said last week a poorly understood Triassic Period reptile group called lagerpetids, known from a few partial skeletons from the United States, Argentina, Brazil and Madagascar, appears to have been the evolutionary precursor to pterosaurs. Lagerpetids, first appearing about 237 million years ago, were generally small and may have been bipedal insect eaters. They could not fly. Pterosaurs became Earth’s first flying vertebrates, with birds and then bats appearing much later.