In new research, paleontologists combined data on the distribution of Triassic pterosauromorph (pterosaur + lagerpetid) fossils with information on the ancient climate in the same areas.
Foffa et al. suggest that lagerpetids — and pterosauromorphs as a whole — probably originated in southwestern Pangea (that is, modern South America), whereas the origin of pterosaurs was predicted at low latitudes in the northern hemisphere. Image credit: James Kuether.
“Pterosaurs were the first vertebrates to evolve powered flight, more than 60 million years before the earliest birds,” said University of Birmingham paleontologist Davide Foffa and colleagues.
“However, our understanding of early pterosaur evolution is hindered by the major temporal and anatomical gaps between these highly modified flying reptiles and their closest terrestrial relatives.”
“The fossil record of pterosaurs and their kin is notoriously incomplete, and fundamental aspects of their early evolution, such as the timing, area, ecological settings of their initial radiation and paleobiology, are still poorly understood compared with other contemporaneous archosaur groups such as dinosaurs.”
In their study, the researchers focused on the distribution of two closely related groups, pterosaurs and lagerpetids.
“Living approximately 240-201 million years ago, lagerpetids were a group of relatively small land- and tree-dwelling active reptiles,” they said.
“These small land-based reptiles are now considered the closest relatives to pterosaurs and, the study reveals, were able to tolerate a wider range of climate conditions than their close flying kin, including the arid areas of the ancient landmass Pangea.”
“This broad tolerance resulted in a widespread distribution of this group.”
“Pterosaurs meanwhile appear to have been at first confined to the more humid conditions found in smaller areas of the ancient world, based on fossils found in modern day Italy and Austria, and southwestern United States, all regions that at the time were close to the equator.”
During the Late Triassic, climatic conditions changed across the globe, leading to a general increase in warm and humid conditions outside the equatorial belt.
This became an opportunity that allowed the flying reptiles to rapidly spread across the globe including to high latitude areas such as what is now Greenland and South America.
“Pterosaurs capture the imagination, with the idea of terrifying reptiles dominating the airs at the time while dinosaurs were roaming the world,” Dr. Foffa said.
“However, pterosaur origins are still wrapped in mystery. Our study adds new information to this puzzle, suggesting that their early evolution during the Triassic period into a dominant group may have been favored by changing climates and environments.”
“Climate change is a leading cause of biodiversity change, both in the present day and the geological past,” said Dr. Emma Dunne, a paleontologist at the Friedrich-Alexander-Universität Erlangen-Nürnberg.
“However, it is only in the last few years — with advances in modeling methods — that paleontologists are getting to grips with how climate change impacted the biodiversity of prominent fossil groups like the pterosaurs.”
“Taken together, ecological models and fossil data paint a coherent picture of pterosaur early evolution,” said Dr. Alessandro Chiarenza, a paleontologist at the University College London.
“Lagerpetids thrived as generalists, while pterosaurs, initially confined to humid-tropical niches and perhaps limited flight performance, occupied equatorial treetops.”
“When global climates shifted and forested corridors opened, those same wings catapulted them into every corner of the planet and ultimately carried them through one of Earth’s greatest extinctions.”
“What began as a tale of missing fossils is becoming a textbook example of how paleoclimate, paleoecology and evolutionary innovation intertwine to illuminate a patchy history that has intrigued paleontologists for two centuries.”
The study was published in the journal Nature Ecology and Evolution.
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D. Foffa et al. Climate drivers and palaeobiogeography of lagerpetids and early pterosaurs. Nat Ecol Evol, published online June 18, 2025; doi: 10.1038/s41559-025-02767-8
