Traditional assumptions on the position of dinosaur nostrils could be all wrong, according to a US scientist.

By looking at modern-day relatives of dinosaurs such as crocodiles and birds, Dr Lawrence Witmer, of Ohio University, has come to the conclusion that dinosaur nostrils are more likely to have been situated on the front of their heads.

Palaeontologists have traditionally placed the nostrils higher up, based on the long debunked 19th-century assumption that the large dinosaurs were aquatic, due to their whale-like size.

Dr Witmer presents his evidence in the journal Science. A full report is available on the BBC web site.