A vast predatory dinosaur with teeth the size of bananas has been identified as a new species by a student at the University of Bristol.

Carcharodontosaurus iguidensis lived during the Cretaceous period, about 95 million years ago. It stood taller than a double-decker bus and is one of the largest carnivorous dinosaurs ever found.

Research by Steve Brusatte, an MSc student, has now established that a specimen belonging to the genus Carcharodontosaurus, unearthed in Niger in 1997, is a separate species.

Mr Brusatte compared the fossils, which include parts of the skull including the snout, lower jaw and braincase, with other Carcharodontosaurus fossils from Morocco, and found critical differences that mark it out as an independent species.

Details of the classification are published today in the Journal of Vertebrate Palaeontology.

Mr Brusatte said that Carcharodontosaurus, which means shark lizard, was among the biggest and most fearsome of all theropods or predatory dinosaurs, but that little was known about the group. The second part of the name comes from the Iguidi region of Niger, where it was discovered.

“The first remains of Carcharodontosaurus were found in the 1920s, but they only consisted of two teeth, which have since been lost,” Mr Brusatte said.

“Other bits of Carcharodontosaurus were found in Egypt and described in the 1930s, but these were destroyed when Munich was bombed in 1944.

Since then a skull of Carcharodontosaurus saharicus turned up in the Moroccan Sahara, and was described a decade ago. So as you can see, evidence for this dinosaur is very rare.”

The remains were discovered in Niger by a team led by Paul Sereno, of the University of Chicago, who is one of the world’s leading dinosaur fossil-hunters. Professor Sereno is also an author of the new paper.

Mr Brusatte said that the two different species of Carcharodontosaurus could possibly have evolved because what is now modern Africa was divided by the effects of climate change.

“The Cretaceous world of 95 million years ago was a time of some of the highest sea levels and warmest climates in Earth history,” he said. “It seems that shallow seas divided Morocco and Niger, promoting evolutionary separation of the species living in the two regions. This has implications for the world today in which temperatures and sea level are rising.

“It is precisely by studying these sorts of ecosystems that we can hope to understand how our modern world may change.”

This new discovery shows that a number of huge theropods – bipedal, carnivorous dinosaurs – were living in Africa 95 million years ago.

Two other large carnivores are known to have inhabited the same Saharan ecosystem at this time. Spinosaurus, a sail-backed creature, may have grown up to 18 metres (60ft) long. The slightly smaller Abelisaurid theropods were characterised by stocky hind limbs and extensive ornamentation of the skull bones. They grew to heights of about 9 metres.

Times Recommends

• The bright side of this winter rain
• Story behind the picture: Snow Leopard, 2008
• Times Charity Appeal: The Place2Be