New Fossils Suggest Flying Reptiles Were 'Swarming' in Northern Brazil
Fossil remains in Brazil have revealed a previously-unknown species of the flying, reptilian pterosaur, which lived 75 to 87 million years ago in the ancient Caiuá Desert.
Uncovered in an ancient bone yard where hundreds of specimens of the novel species have been found, the new creature offers a window into the world of pterosaurs, shining new light on the fact the beaked animals apparently had the ability to fly soon after birth and may well have nested in large, dynamic communities, according to a report by Smithsonian.com.
Located just outside of Brazil's city of Cruzeiro do Oeste, the fossil site was discovered by Alexander Dobruski, a local for whom the new creature, Caiuajara dobruskii, was named after, along with his son, João, was digging a runoff ditch back in 1971 -- and then, four years later, sent some of the unearthed fossils for scientific study to the Universidade do Contestado in central Brazil -- where the bones ended up sitting in storage for the next three decades.
In 2011, Luiz Carlos Weinschütz, a geologist at the university's paleontological center in Mafra, and fellow paleontologist Paulo César Manzig stumbled upon the forgotten collection of remains while doing research for a book.
The researchers soon traveled to Cruzeiro do Oeste, where they found a jaw-dropping assortment of prehistoric fossils.
"When we arrived at the discovery site, the bones were visible-many pterosaur bones right in front of my eyes," Manzig recalled in the Smithsonian.com piece. "It was one of the most exciting moments of my life."
Researchers now estimate the bone bed spans an area of about 4300 square feet.
Geologic data pin the bone bed to the late Cretaceous period, when pterosaurs lived near small lakes in the surrounding desert, but also along the region's northern coast.
After painstakingly excavating about 66 square feet of the local sandstone, the researchers identified at least 47 individual pterosaurs, including several juveniles.
The reptiles had wingspans of 2.1 to 7.7 feet, ranging roughly from the size of a small model airplane up to that of an albatross. They also lacked teeth, meaning the creatures most likely relied on a fruit-heavy diet.
By studying the specific shapes of the fossilized bones and other anatomical characteristics they found, the researchers figured out what branch of the pterosaur family tree the new creatures came from.
Other findings, however, such as a unique divet in the jaw and a bony ridge above the eye, indicated the Caiuajara dobruskii was an entirely new species.
Like many other winged reptiles, the new type of pterosaur also sported a unique head crest. Adults had larger, steeper crests as juveniles had smaller, less-sloped ones.
"Some researchers think that the crests were only display structures, others envision them as being a form of sexual dimorphism-males have them, females don't," Alexander Kellner, a paleontologist at the Museu Nacional in Rio de Janiero and another co-author on the study, explained to Smithsonian.com. "Personally, I think it was a mix of different functions."
Finding such a high volume of these creatures, the researchers said, is rare, and the fact that they were discovered clumped together within the same 5-foot rock layer suggests the animals lived and died in the same place.
"This certainly indicates that at least some of these animals were gregarious," said Mark Witton, a paleontologist at the University of Portsmouth in the United Kingdom. "The lake that Caiuajara lived next to must have been swarming with pterosaurs."
Other scientists, however, speculate seasonal flooding could have washed bones into the area from animals that died elsewhere.
"Such mass accumulations are not uncommon and are not necessarily evidence of animals living and dying in groups," said Hans-Dieter Sues, a vertebrate paleontologist at the National Museum of Natural History in Washington, D.C.
Ultimately, what killed off the particular flying lizards?
Drought and desert storms are the main contenders right now, though "any climate oscillation might have been fatal for fragile individuals," said Weinschütz.