Scientists have found a fossilized skull of a new species of pterosaur in Argentina's Patagonia region. The previously unknown species has been named "Allkaruen koi."

The flying reptile, believed to be the oldest pterosaur that lived during the early Jurassic period, thrived between 199.6 million years and 175.6 million years ago.

The now-extinct pterosaurs were very well adapted to flight as suggested by their lightweight bones. An earlier study also found that these creatures have air sacs extending from the lungs to keep the body's density down. The Allkaruen koi also featured an elongated digit that supported a wing membrane.

Scientists, however, know very little about these ancient creatures because of poor fossil records. Fortunately, an intact braincase was discovered along with the fossil remains, giving scientists a better chance at looking into the neuroanatomy of the creature more closely.

The fossils of the flying reptile were discovered in a bone bed with other pterosaur remains. The skull measured only about 7 centimeters (2.75 inches) long, which means that the Allkaruen koi was a small species of pterosaur. Some species of pterosaurs were tiny but others could grow to the size of giraffes. The larger ones may have used their limbs to leapfrog when they fly. Archaeologists were also able to unearth a vertebra and jaws.

"Compared to the other similar species we know of, this one is about the size of an egret, but it's very difficult to know exactly, since we only have parts of the skull and some neck vertebrae," said study researcher Ariana Carabajal, from the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) in Argentina.

By using computed tomography scans, Carabajal and colleagues built digital models of the animal's inner ear and the interior of the skull, which helped find the place of the Allkaruen koi in the pterosaur family tree.

The researchers said it is rare to find an intact pterosaur and there is much to know about the evolution of pterosaur skulls and brains over time.

Researchers learned that some of features of the skull of the Pterodactylus, a genus of pterosaurs, evolved by the early to middle Jurassic period.

"Allkaruen, from the middle lower Jurassic limit, shows an intermediate state in the brain evolution of pterosaurs and their adaptations to the aerial environment," noted paleontologist Diego Pol, another member of the research team. "As a result, this research makes an important contribution to the understanding of the evolution of all of pterosaurs."

Details of the find are published in the journal PeerJ on Aug. 30.