Superb fossil seized in police raid reveals secrets of prehistoric flying reptile
Hidden in barrels and loaded onto trucks, thousands of limestone slabs were to be smuggled out of Brazil in 2013. From a quarry in the country’s famous Araripe Basin, they were no ordinary rocks. They contained preserved remains and impeccable footprints of creatures that lived millions of years ago.
Intended to be sold to museums and potentially to private collectors around the world, the fossil bounty is said to have earned its poachers thousands of dollars, if not more. Instead of, police raids in an investigation codenamed Operation Munich intercepted the illegal export and sent nearly 3,000 of the seized specimens to the University of São Paulo.
Among the relics was a strange winged reptile, standing nearly four feet tall with a jaw similar to a bird’s beak and a larger-than-life headgear. Now scientists report this is the first nearly complete skeleton of the pterosaur species Tupandactylus navigans, who lived in the early Cretaceous, around 110 million years ago.
“I have seen many exceptional and beautifully preserved pterosaurs in Brazil and abroad, but specimens like this one, which is almost complete and articulated, with soft tissue preservation, are rare,” explains Fabiana Rodrigues Costa , paleontologist at the Federal University of ABC in São Paulo, Brazil, and co-author of study published today in the journal PLOS ONE. “It’s like winning the lottery.
The species was first described in 2003 by German and English scientists using two skulls. But this is the first time that paleontologists have been able to study the rest of the animal’s body, including some soft tissue and the bones of the neck, wings and legs. The findings could one day help resolve an ongoing debate about how the gargantuan ridges on the heads of these reptiles may have affected their flight abilities.
“It’s a one-of-a-kind fossil,” says Costa.
Ancient reptiles of the sky
Pterosaurs were close cousins of dinosaurs and lived alongside them. While dinosaurs thrived on earth, pterosaurs dominated the sky. They coexisted from the end of the Triassic over 200 million years ago until the end of the Cretaceous 66 million years ago when the two groups died out in the global calamity triggered by a asteroid.
But pterosaurs do not have living descendants, unlike dinosaurs, which birds survive. Fossils are the only window into the appearance and life of these prehistoric flying creatures, and pterosaur fossils are extremely rare. Their delicate bones keep poorly, often yielding only skeletal fragments.
Paleontologists have recovered pterosaur remains primarily from sediments that were once submerged underwater. Soft mud quickly buried carcasses after they sank to the bottom of lakes or seas, and poor oxygen conditions limited their decomposition there.
The Araripe Basin in Brazil, which was once covered with salt lagoons but is now arid and bushy, yields numerous exceptionally preserved fossils buried in layers of limestone. “You open the stone like you open a book, and inside these pages you will find fossils,” says paleontologist and study co-author Felipe Lima Pinheiro at the Federal University of Pampa in São Gabriel , in Brazil.
Twenty seven from over 110 known pterosaur species came from this region. Tapejarids are among the most diverse and abundant groups, especially those of the genus Tupandactyl, all of which have oversized, flamboyant head ridges.
While the Araripe Basin is rich in fossils, Pinheiro says pterosaur fossils are not commonly found, let alone nearly complete. The illegal fossil trade is not helping. Specimens often end up in the hands of foreign buyers, unlike Brazilian museums and research institutes.
“The almost complete fossil is a very important find,” says Rodrigo Vargas, a graduate student in paleontology. Pegasus from ABC Federal University in Santo André, Brazil, which was not involved in the research. “This is huge news for Brazilian paleontology.”
In 2014, when the Tupandactylus navigans specimen came to the University of São Paulo, its skeleton was encrusted in six beige colored limestone slabs. Victor Beccari, a graduate student affiliated with the university and lead author of the new study, first noticed that the pterosaur’s headgear made up almost three-quarters of its skull. “It’s so huge for the size of the animal, like a peacock’s tail,” he says.
To scientists who describe Tupandactylus navigans in 2003, the cranial crest resembled windsurfing sails and therefore a propulsion system to facilitate flight. To make this possible, they imagined an animal with a short neck and bony tendons locking the neck vertebrae together.
With access to the full skeleton, Beccari and his colleagues were able to investigate the animal’s fitness for flight. The team generated a three-dimensional model of the skeleton using a computed tomography (CT) scanner to X-ray ancient bones.
Actually Tupandactylus navigans had a long neck, long legs, and relatively short wings. The results suggest that the animal was a better walker than an acrobat. The creature’s extravagant cranial crest – perhaps an ornament for sexual display – would limit it to undertaking short-range flights, possibly to flee predators.
But another mystery of this vertical ridge prompts researchers to seek more clues. A different species of tapejarid, known as Tupandactylus imperator, lived next door Tupandactylus navigans. The first, known from four skulls and sporting an even larger crest, shares a similar head shape with Tupandactylus navigans, and researchers wonder if they could really be two sexes of the same species.
“It’s a hunch.” said Pinheiro. “Full imperator skeleton, if we find it, will help us. Perhaps the limestone of the Araripe Basin will produce more tapejarid bones, revealing more secrets about the lives of these enigmatic reptiles.
For now, thanks to the raid, scientists and the general public all have the opportunity to see Tupandactylus navigans with their own eyes: it is remarkable skeleton was exhibited at the São Paulo Geosciences Museum since 2017.