A festive flying reptile family reunion 150 million years in the making

A new study published this week has found nearly 50 'hidden' relatives of Pterodactylus, the first pterosaur, that will allow scientists to reconstruct this flying reptile's life history from hatchling to adulthood.

Nearly 250 years ago, the very first pterosaur fossil was found in a quarry in northern Bavaria. Dubbed Pterodactylus, this 150-million-year-old fossil provided the first evidence for an extraordinary group of flying reptiles that filled the skies of the Mesozoic, soaring over the heads of dinosaurs on wings that could span up to 10 metres or more. While this first pterosaur was only the size of a turtle dove, it completely reshaped our understanding of prehistoric life.

Despite being the original 'pterodactyl', Pterodactylus was soon quite literally overshadowed in the public consciousness by more dramatic, giant pterosaurs like Pteranodon and Quetzalcoatlus, whichstole the spotlight. But Pterodactylus remained a favourite among pterosaur scientists.

Over the centuries, Pterodactylus and other similar pterosaurs from Bavaria have been central to ongoing scientific study, helping shape much of what we know about pterosaurs, from the shape of their wings and how they flew, to their diet and how they grew. But one question has always lingered: which of these many pterosaurs are truly Pterodactylus and which belong to completely different species? This confusion has persisted for centuries... until now. Thanks to a new study that analysed dozens of specimens of Pterodactylus in museums around the world, the mystery has been solved, and the true identity of these fossils has finally been uncovered.

Shining powerful UV torches on fossil bones to make them fluoresce, University of Leicester paleontologists Robert Smyth and Dr Dave Unwin were able to bring to light tiny near-invisible bony details that distinguish one kind of pterosaur from another. Using Pterodactylus' unique features, found in the head, hips, hands and feet, Smyth and Unwin systematically checked other fossils from the same deposits and to their surprise discovered many other examples of Pterodactylus 'hiding' in among what were thought to be other species of pterosaur.

Lead author Robert Smyth, a doctoral researcher in the in the Centre for Palaeobiology and Biosphere Evolution (School of Geography, Geology and the Environment at the University of Leicester), explained: "By examining lots of fossils in collections across Europe we were able to reidentify more than forty specimens as Pterodactylus. UV stimulated fluorescence is astonishing in the amount of detail it can reveal. Features that were once hidden were glowing in plain sight."

In an eyeblink the entire concept of Pterodactylus changed dramatically. With nearly 50 examples recognised so far, our knowledge of this most important of pterosaur has exploded. As co-author Dr David Unwin from the University of Leicester explained: "We can now construct a complete and highly detailed skeletal anatomy for this key pterosaur. Soft tissues are fossilised in more than twenty examples so we can also reconstruct head crests, body shape, foot webs and even the wings."

The result? A sprawling family portrait of Pterodactylus, providing a unique opportunity to reconstruct its full life history. This spans from robin-sized hatchlings (affectionately dubbed 'flaplings') to 'teenage' Pterodactylus, all the way to raven-sized adults with wingspans nearly ten times larger.

Dr Unwin added: "UV stimulated fluorescence is a well-known technique, but the difference in this case is that we have been able to combine new high quality light sources with a systematic 'catch-all' approach, and it's going to have a revolutionary impact on our understanding of pterosaurs."