Fossils of two juvenile pterosaurs, dating back 150 million years, have provided critical insights into the circumstances surrounding their deaths. Discovered in the Solnhofen limestone deposits in southern Germany, these remains indicate that the hatchlings succumbed to a violent storm, a revelation that sheds light on a long-standing mystery in paleontology.
Remarkable Preservation of Fragile Bones
The delicate nature of pterosaur bones presents significant challenges for fossilization. As noted by paleontologist Rab Smyth from the University of Leicester in the UK, “Pterosaurs had incredibly lightweight skeletons. Hollow, thin-walled bones are ideal for flight but terrible for fossilization.” The preservation of these specific fossils is particularly notable, given that juvenile pterosaurs are generally underrepresented in the fossil record due to their fragility.
Researchers have identified the hatchlings as belonging to the Pterodactylus genus, with the two specimens, informally dubbed Lucky I and Lucky II, remarkably intact and articulated. Both fossils exhibit broken wing bones, suggesting a violent event caused their demise. These breaks, characterized by clean, slanted fractures, indicate that the wings were damaged by a forceful twisting motion.
Stormy Conditions and Fossilization
The circumstances of their death are linked to the unique environmental conditions of the time. The Solnhofen limestone was once part of a saltwater lagoon, where sedimentation played a vital role in fossil preservation. The research team reconstructed the events leading to the hatchlings’ deaths, concluding that they were caught in a powerful storm. The winds would have severely impacted the fragile juveniles, breaking their wing bones and ultimately tossing them into tumultuous waters.
Once submerged, sediments quickly covered the remains, preserving them for millions of years. This hypothesis is further supported by the presence of numerous other small remains found in the same fossil bed. Larger, mature pterosaurs likely survived such storms, floating away rather than being buried, which explains the prevalence of juvenile fossils in this specific location.
“For centuries, scientists believed that the Solnhofen lagoon ecosystems were dominated by small pterosaurs. But we now know this view is deeply biased,” Smyth stated. This new understanding suggests that many juvenile pterosaurs were not native to the lagoon but were instead swept into the area from nearby islands during severe weather events.
The findings from this research have been published in the journal Current Biology, offering valuable insights into the lives and deaths of these ancient flying reptiles. The study not only enhances our understanding of pterosaur biology but also emphasizes the impact of environmental factors on fossilization processes.
