For fossil hunters, it represents one of those breakthrough moments. A pterosaur has been found in China beautifully preserved with an egg. The egg indicates this ancient flying reptile was a female, and that realisation has allowed researchers to sex these creatures for the first time. Writing in Science magazine, the palaeontologists make some broad statements about differences in pterosaurs, including the observation that only males sported a head-crest. David Unwin, a palaeobiologist in the Department of Museum Studies at the University of Leicester, was part of the research team. He told the BBC the discovery was astonishing: "If somebody...