Pterosaurs, extinct flying reptiles that soared alongside dinosaurs, are among the most intriguing creatures in Earth history. While some later species had wingspans of up to 10 metres, early pterosaurs were much smaller, usually not exceeding two metres.
The newly identified species Skiphosoura bavarica sheds light on the evolutionary steps that enabled these creatures to close this size difference and acquire advanced anatomical features. The discovery, led by David Hone from Queen Mary University of London, is a rare find that deepens our understanding of pterosaur evolution.
A unique pterosaur fossil
The name Skiphosura bavarica translates as “Bavarian swordtail” and reflects its characteristic stiff, pointed tail and the southern German region where it is found. What makes this fossil truly amazing is its preservation. Nearly every bone of the animal has been repaired, and unlike most pterosaur fossils, which are generally flattened, this specimen is preserved three-dimensionally.
With a wingspan of nearly two meters (comparable to a golden eagle), Scyphosura provides a rare insight into the morphology of transitional pterosaurs.
“This is an incredible discovery. It really helps us understand how these magnificent flying animals live and develop. We hope this study will provide a basis for future studies on this important evolutionary transition.” Hawn said.
A broad classification of pterosaur fossils
For more than 200 years, scientists have divided pterosaurs into two main groups. Neptrodactyloids are the first pterosaurs with a small head, short neck, long tail, a short bone at the wrists of the wings, and a long fifth toe.
Pterodactyloids were a later species, characterized by large heads, long necks, short tails, long wrist bones, and short fifth toes. While this broad classification was useful, it left significant gaps in understanding how pterosaurs transitioned between these forms. Discoveries in the 2010s helped answer some of these questions.
These intermediate species showed that the head and neck adapted first, with other anatomical changes occurring later. But scientists were interested in what happened immediately before and after the emergence of lepidoptera.
Closing the evolutionary gap
Scyphosura Bavaria offers vital clues. In evolutionary terms, it falls between anthopterans and pterodactyloids and shows a combination of features of both groups. It has the pterodactyloid head and neck typical of Darwinians, but also exhibits advancements such as an elongated wrist, shortened fifth toe, and a shortened tail, although not as prominent as later pterodactyls.
This discovery, combined with a newly reconstructed evolutionary tree, allows researchers to track the progression of anatomical changes in pterosaurs. The study also sees Dirk’s Scottish pterosaur as a transitional species between early pterosaurs and Darwinosaurs.
Together, Dirk and Scyphosura explain step by step how pterosaurs evolved into the large, advanced forms seen in later pterodactyloids, completing a nearly uninterrupted series of evolutionary adaptations.
Adapt to larger sizes
Interestingly, both Dearc and Skiphosoura were unusually large compared to other species of their time. This suggests that adaptations that allowed pterodactyloids to reach gigantic sizes, such as larger heads and longer necks, began to appear in transitional forms such as Scyphosaura. These changes likely provided benefits such as improved flight ability and more efficient foraging.
Analysis of pterosaur fossils
Preparation and analysis of fossils was a task that required modern technology and expertise. Unlike typical flat fossils, the three-dimensional preservation of Scyphosura required painstaking work.
“As a taxidermist, I have worked on more than 60 pterosaur specimens from the Solnhofen Limestone,” said Stefan Seltzer, co-author of the study that prepared the specimen. “During final preparation, I realized that this specimen had features that combined features of both major groups of pterosaurs, with the shortened tail being the most important diagnostic feature.” Digital imaging has also played an important role in fossil analysis.
“The specimen was divided into bones of various qualities and often stacked on top of each other,” explains René Lauer of the Lauer Foundation for Paleontology, Science and Education.
“Digital photography of the sample taken in both visible and ultraviolet light greatly helped identify these elements and better analyze small details that cannot be noticed in normal daylight alone.”
Rethinking the evolution of pterosaurs
The discovery of Skiphosura bavarica provides a detailed roadmap of pterosaur evolution, providing insight into how these creatures developed the features that eventually allowed them to dominate the skies. By clarifying the sequence of anatomical changes, this fossil represents an important milestone in understanding the evolutionary history of pterosaurs.
“Pterosaurs have long been symbols of the unique life of the past. “Scyphosura is an important new form for explaining the evolutionary relationships of pterosaurs and therefore how this lineage emerged and changed,” said paleontologist Adam Fitch of the University of Wisconsin-Madison, one of the study’s authors.
By continuing to study this remarkable find, researchers hope to uncover more details about how pterosaurs adapted and evolved in prehistoric ecosystems.
“This is an incredible discovery. It really helps us understand how these magnificent flying animals lived and evolved,” Hone said.
Thanks to Skiphosoura bavarica, scientists have gained a clearer picture of the evolutionary path that transformed tiny early pterosaurs into the majestic flying reptiles of the Mesozoic era, cementing their role as an important link in the history of life on Earth. The study was published in the journal Current Biology.
Source: Port Altele
