Tyrannosaurus rex had lips over its teeth, research suggests

An artist’s impression of a juvenile Edmontosaurus disappearing into the lipped mouth of a Tyrannosaurus. Photograph: Mark Witton/University of Portsmouth/PA

While T rex is often depicted prowling the landscape while sporting a toothy grin, its fearsome teeth may actually have been concealed behind a pair of thin, scaly lips, research suggests.

Experts say the perception that theropods were lipless arose because of the huge size of their teeth, and because their closest living toothed relatives – such as crocodiles and alligators – do not have lips.