Paleontologists working in China say they've unearthed the first preserved eggs from a 100-million-year-old pterosaur, a previously unknown species of the prehistoric flying reptiles that flew through the skies in the era of the dinosaurs.
It is the first worldwide discover of three-dimensionally preserved eggs of a pterosaur, they said; previously only four flattened eggs have been found.
The international research team has given the new species the scientific name Hamipterus tianshanensis, after the location where the remains of dozens of adult pterosaurs and the eggs were found near the city of Hami in northwest China's Xinjiang Uygur Autonomous Region.
"Most of the fossils are relatively intact, and this is favorable for assembly of a complete pterosaur skeleton," said Chinese Academy of Sciences researcher Wang Xiaolin.
Five intact eggs were found, said Wang, a paleontologist with the academy's Institute of Vertebrate Paleontology and Paleoanthropology.
The fossilized eggs would have been pliable and soft, with a thick inner membrane under a thin, harder outer shell, similar to eggs laid by several kinds of snakes and lizards, Wang said.
They were probably buried in the sand on the shoreline of a prehistoric lake to keep them from drying out, the researchers said.
"They are the best-preserved pterosaur eggs ever found," Wang said.
The large number of adult pterosaur fossils at the site suggests the flying reptiles lived in large social groups, and the eggs are evidence it might have been a nesting site, the paleontologists reported in the journal Current Biology.
"This is definitely the most important pterosaur site ever found," said Zhonghe Zhou, director of the paleontology institute.
"One of the significant (aspects) of this discovery -- hundreds of individuals and eggs together from one site -- is that it confirmed that pterosaurs were gregarious, and the population size is surprisingly large," he said.
The researchers say Hamipterus tianshanensis had a crest on top on an elongated skull, numerous pointed teeth ideal for catching fish, and sported a wingspan reaching almost 12 feet.
The large number of fossil pterosaurs at the site was likely the result of a large storm that killed all of the Creataceous period creatures at once, they suggested.
Pterosaurs had fragile, light skeletons -- necessary to make flight possible -- that don't preserve well, which is why knowledge of their configuration and their behaviors difficult to come by, they said.
The international team of paleontologists included Chinese scientist working with colleagues from Brazil and other countries.
