Stunning fossil eggs provide insight on ancient flying reptiles

[Buster's Uncle]

Stunning fossil eggs provide insight on ancient flying reptiles
Reuters
By Will Dunham  1 hour ago



An artist rendition depicts ecological reconstructions of Hamipterus, the flying reptiles that lived alongside the dinosaurs. REUTERS/Chuang Zhao/Handout via Reuters



WASHINGTON (Reuters) - A spectacular fossil find in China - a prehistoric egg extravaganza from 120 million years ago - is providing unique insight into the lifestyle and gender differences of pterosaurs, the flying reptiles that lived alongside the dinosaurs.

Until now, only four pterosaur eggs had ever been found, and all were flattened during the process of fossilization.

But Chinese scientists said on Thursday they had unearthed five pterosaur eggs preserved beautifully in three dimensions at a site in northwestern China that also includes no fewer than 40 adult individuals of a newly identified species that lived in a bustling colony near a large freshwater lake.

"This is definitely the most important pterosaur site ever found," said paleontologist Zhonghe Zhou, director of the Chinese Academy of Sciences' Institute of Vertebrate Paleontology and Paleoanthropology.

The creature, Hamipterus tianshanensis, had a crest atop its elongated skull, pointy teeth for catching fish and a wingspan of more than 11 feet (3.5 meters).

The five oblong eggs were "pliable" with a thin, hard outer layer marked by "cracking and crazing" covering a thick membrane inner layer, making them resemble the soft eggs of some modern snakes and lizards, said paleontologist Xiaolin Wang, another of the researchers.



An artist rendition depicts ecological reconstructions of a male Hamipterus, the flying reptiles that lived alongside the dinosaurs.REUTERS/Chuang Zhao/Handout via Reuters


"They are the best-preserved pterosaur eggs ever found," Wang said.

The site was remarkable for what it reveals about how pterosaurs lived. At least 40 male and female individuals have been identified, and there may be hundreds in all, Wang said.

The site indicates pterosaurs lived in large colonies, in this case nesting near the lake and burying eggs in moist sand to prevent them from becoming desiccated, Wang said.

"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," Zhou said.

The fossils illustrated important sex differences in pterosaurs. For example, males possessed distinctly larger head crests.

"In Hamipterus, size, shape and robustness are decided by the gender," Wang said, adding that this contradicts a previous notion that "sexual dimorphism in pterosaurs was only reflected in the absence or presence of the crests."

The site, discovered in Xinjiang province in 2005, was preserved probably after the Cretaceous period creatures perished together in a large storm, Zhou said.

Pterosaurs were Earth's first flying vertebrates, with birds and bats appearing much later. They thrived from about 220 million years ago to 65 million years ago, when they were doomed by the asteroid that also killed the dinosaurs.

Knowledge about pterosaurs has been spotty, with their fragile skeletons not lending themselves well to fossilization. Little has been known about their behavior.

"I have been truly amazed by the abundance of bones and the number of eggs as well the great potential of more discoveries from the site," Zhou said.

The genus name, Hamipterus, means "Hami wing," honoring nearby Hami City. The species name, tianshanensis, refers to the nearby Tian Shan mountains.

The study appears in the journal Current Biology.

(Reporting by Will Dunham; Editing by Jonathan Oatis)


http://news.yahoo.com/stunning-fossil-eggs-insight-ancient-flying-reptiles-162358926.html

[Buster's Uncle]

First 3D Flying-Reptile Eggs Discovered in China
LiveScience.com
By Tanya Lewis, Staff Writer  8 hours ago



One of the three-dimensionally preserved pterosaur eggs that were found in China.



The first three-dimensionally preserved eggs of ancient winged reptiles that lived more than 100 million years ago have been unearthed in China.

Five intact eggs were found, along with dozens or more adult fossils, of a new type of pterosaur, a group of prehistoric winged reptiles that dominated the skies during the time of dinosaurs. These creatures included some of the largest flying animals that ever existed.

"We found a lot of pterosaur bones which belong to different individuals in the sites, with five eggs," said study researcher Xiaolin Wang, a paleontologist at the Institute of Vertebrate Paleontology and Paleoanthropologyat the Chinese Academy of Sciences in Beijing.  [See photos of the ancient pterosaur eggs & fossils]

The fossil record of pterosaurs is lacking, and before now, only four individual flattened pterosaur eggs had been discovered by scientists.

The researchers found the fossils of the new genus and species, Hamipterus tianshanensis, in an area first excavated in 2005 in the Turpan-Hami Basin, located south of the Tian Shan Mountains in Xinjiang, in northwestern China. Thousands of bones may be hidden in the area where the eggs and skulls of adult male and female pterosaurs were found, the researchers said.

The newly uncovered pterosaurs likely perished in a storm about 120 million years ago, during the Early Cretaceous period, Wang said.

Wang and his team found that the eggs were soft and pliable, with a thin, hard outer shell and a thick, soft inner membrane, similar to the eggs of some snakes. The pterosaurs probably buried their eggs in the sandy shore of an ancient lake to prevent them from getting dried out, the researchers said.

The researchers also uncovered many adult pterosaur fossils nearby. They examined 40 male and female adult specimens, and found differences in the size, shape and robustness of the animals' head crests.

Like modern bats and birds, pterosaurs were flying vertebrates, but their wings were different. Birds have fused palms and asymmetric feathers, whereas bats and pterosaurs have membranes supported by fingers, Wang told Live Science. Bat wings are also attached to four fingers, while pterosaur wings are only attached to the fourth finger, he said.

The newly found cluster of fossils suggests these pterosaurs lived together in large social groups, the researchers said. The creatures likely belonged to gregarious colonies, because the fossils had not been transported far from where they originated, Wang said.

Finding the eggs near so many adult pterosaurs could indicate that a nest site may be nearby. The vulnerability of the pterosaur eggs may also explain why so few have survived in the fossil record, the researchers said.

Wang and his colleagues reported their findings today (June 5) in the journal Current Biology.


http://news.yahoo.com/first-3d-flying-reptile-eggs-discovered-china-162346113.html