Will the real dinosaurs stand up?

Most of the newly discovered dinosaurs are just that - new to science, an assessment concludes.

With many past fossil finds named on the basis of partial remains, there has been concern that a lot of double counting has been taking place.

Recent studies had even suggested this error rate might be as high as 50% - with some species being catalogued with several aliases.

This plant-eating Jurassic dinosaur was named Yinlong downsi by Xu Xing and colleagues in 2006. Xu Xing is the most prolific namer of new dinosaurs: this is his 25th new species. This type specimen is essentially complete, typical of the good practice of most workers today.

But the journal Biology Letters reports that modern practice is now very good.

"My research suggests we're getting better at naming things; we're being more critical; we're using better material," said Professor Michael Benton from Bristol University, UK.

The scientist looked at the original descriptions of all 1,047 species of dinosaurs ever named, from 1824 to the present day.

He assessed the quality of the specimens on which the names were founded - the type specimens. Professor Benton said some 500 were genuinely distinct, and the confidence surrounding the latest discoveries - about one new species a fortnight - was now very high.

"The bane of the dinosaurologist's life is species that have been named on the basis of incomplete specimens," Professor Benton explained.

"In Victorian times, palaeontologists were keen to name new species, and in the excitement of the great 'bone wars' for example, from 1870 to 1890, they rushed into print with new names for every odd leg bone, tooth, or skull cap that came their way.

"Later work, on more complete specimens, reduced more than 1,000 named dinosaurs to 500 or so."

Professor Benton said science had now put in place far more rigorous naming protocols, dramatically reducing the "alias problem".

Since 1960, the great majority of new species are founded on more or less complete specimens, sometimes even whole skeletons.

Professor Benton has a critical interest in the topic because he studies the evolution of dinosaurs. He tries to understand how this famous animal group changed and diversified over almost 200 million years.

"There's no point somebody such as myself doing big statistical analyses of numbers of dinosaur species through time - or indeed any other fossil group - if you can't be confident that they really are genuinely different," he told BBC News.

"This is important also for studies of modern biodiversity. People have also been looking at our current knowledge of mammals and insects and other animal groups and asking the simple question: are the species totals and lists we use for important conclusions - including to give political advice about endangered species - are they correct?

"There's been a big debate about vast extinctions among amphibians. We have to know what the species are first, before we can talk about that."