Ancient flying reptile's head crest looked like a yacht's sail

By Will Dunham

WASHINGTON (Reuters) - A flying reptile whose head was topped with a big bony crest shaped like the sail of a yacht swooped through the skies over Brazil roughly 90 million years ago.

Scientists announced on Wednesday the remarkable discovery of about 50 fossilized skeletons of a creature called Caiuajara dobruskii, a type of flying reptile known as a pterosaur that lived alongside the dinosaurs, at a site in southern Brazil.

These pterosaurs, whose wingspans measured up to nearly 8 feet (2.35 meters), inhabited a lakeside oasis in a large desert region during the Cretaceous Period, living in vibrant colonies with others of the same species of all ages, they said.

"This helps us to have a glimpse on the anatomical variation achieved by this species from young to old," said Alexander Kellner, a paleontologist with Brazil's National Museum at the Federal University of Rio de Janeiro, who led the study.

Many pterosaurs, especially the later ones, boasted elaborate and sometimes large head crests. Caiuajara's head was topped with a big triangular crest that looked like "a bony sail," according to Kellner. "It looks bizarre," he said.

There is no indication that the crest was limited to either males or females, but it appears to have become ever larger relative to the rest of the body as the pterosaur matured.

"The size of the crest was small in young animals and very large in older ones," Kellner added.

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

The researchers described 47 skeletons in their study published in the scientific journal PLOS ONE and said they have identified 10 more not described in the paper. They said this species lived about 80 to 90 million years ago.

Caiuajara was toothless and most likely a fruit eater, Kellner said. The skeletons of the juveniles strongly suggested they could fly at a very young age, Kellner added.

Knowledge about pterosaurs has been spotty, with their fragile skeletons not lending themselves well to fossilization. The sheer number of Caiuajara individuals discovered and their variety of ages have made it one of the best understood pterosaurs ever found, the researchers said.

Chinese scientists in June said they had unearthed no fewer than 40 adult individuals of another newly identified pterosaur species as well as five pterosaur eggs - very rare indeed - preserved beautifully in three dimensions. [ID:nL1N0OK24L]

No eggs of Caiuajara have been found at the site in Brazil. "Not yet. But one is allowed to dream, correct?" said Kellner.

(Reporting by Will Dunham; Editing by Tom Brown)