Male pterosaurs sporting spectacular head crests were the peacocks of the dinosaur era, a new study has shown.

A rare fossil find has for the first time allowed experts to determine the sex of one of the flying reptiles.

The discovery confirms what many suspected, that the showy head ornaments were male features designed for courtship.

The evidence comes from Mrs T, the nickname given to a female pterosaur preserved together with the egg she was about to lay.

Pterosaurs – favourites of Hollywood film-makers – were flying reptiles that lived alongside the dinosaurs, some of which grew as large as light aircraft.

Mrs T was a 160 million-year-old Darwinopterus pterosaur whose skeletal remains were uncovered in Liaoning Province, north-east China.

Because she was found with her egg, scientists know that she must have been female. The pterosaur had relatively large hips to accommodate the passage of eggs, but no head crest.

Other Darwinopterus specimens, now known to be male, have smaller hips and well-developed crests. Scientists believe these were probably used to ward off rivals or attract mates. David Unwin, from the University of Leicester, whose team describe the find in the journal Science, said: “Pterosaurs, flying reptiles, also known as pterodactyls, dominated the skies in the Mesozoic Era, the age of dinosaurs, 220-65 million years ago. Many pterosaurs have head crests. In the most spectacular cases these can reach five times the height of the skull.”

Future pterosaur fossil finds in which the skull or hips are preserved can now help scientists to determine the sex of the creatures.