A new pterosaur fossil from southern Germany has shed light on how pterosaurs went from species with eagle-sized wingspans to the most enormous animals ever to fly in Earth’s skies.
“This is an incredible find,” says David Hone from Queen Mary University of London. “It really helps us piece together how these amazing flying animals lived and evolved. Hopefully this study will be the basis for more work in the future on this important evolutionary transition.”
Pterosaurs are an extinct group of flying reptiles closely related to dinosaurs and lived during most of the Mesozoic Era (also known as the “Age of Dinosaurs,” which lasted from 252 to 66 million years ago).
Over 200 years of paleontological study has traditionally split pterosaurs into the early non-pterodactyloids and the later, much larger pterodactyloids. Pterodactyloids include Quetzalcoatlus northropi, a reptile with an estimated 11-metre wingspan, which is larger than some aircraft.
The early species share several physical traits including short heads on short necks, a short bone in the wrist, a long fifth toe on the foot, and long tails. In contrast, the pterodactyloids have the opposite traits: large heads on long necks, a long wrist, a short fifth toe and short tail.
Until recently, palaeontologists had incomplete information about which parts of the body changed and when. Then, in 2010, a series of intermediate fossils called darwinopterans revealed that the head and neck changed first. But questions remained about the rest of the body.
Now, a UK-led team of palaeontologists has described a new pterosaur fossil with remarkable 3D preservation that lived after the darwinopterans and before the large pterodactyloids.
Named Skiphosoura bavarica after its sword-like pointed tail, the new fossil fills an evolutionary gap and shows traits intermediate between the older darwinopterans and the later, larger pterodactyloids.
Specifically, the team described Skiphosoura as having a longer wrist, a shorter fifth toe, and a shorter tail compared to older species but not to the same extreme as the larger pterodactyloids. They also note that Skiphosoura is unusually large for its time, suggesting that these physical changes enabled pterosaurs to reach enormous sizes.
“Pterosaurs have long been symbols of the unique life of the past,” says co-author Adam Fitch from the University of Wisconsin-Maddison in the United States. “Skiphosoura represents an important new form for working out pterosaur evolutionary relationships and by extension how this lineage arose and changed.”
The study is published in the journal Current Biology.
