A large windowless room in the recesses of Wits University holds many mysteries. They lie on shelves, in drawers and some of them have yet to be noticed. They aredinosaur fossils, millions of years old, which lie in the storage facility of the Evolutionary Studies Institute.This collection of fossils - some date back a quarter of a billion years - is becoming the new dig site that keeps yielding new species.The latest was a 200million-year-old dinosaur named Sefapanosaurus, revealed last month.For 80 years Sefapanosaurus remained hidden in the collection, until students Alejandro Otero and Emil Krupandan noticed the bones didn't fit with any of the other species they knew.The problem was they had little to go on. Someone had spent a lot of time preparing the bones by expertly removing the matrix, the rock that once encased the fossils. The person had even neatly numbered each bone with marking pen."We tried to look at the handwriting, but that didn't work," said palaeontologist Jonah Choiniere.The only scrap of information they have is that the fossils were found somewhere near Zastron in the Free State.By getting the dinosaur described, Choiniere hopes that someone will come across fossils of the species in the field, and perhaps they might even find the site it came from.Not far from Sefapanosaurus is another set of bones. These also belong to a new species, but this beast has a nickname - the Highland Giant.This dinosaur was discovered by South Africa's star of fossil collecting, James Kitching.He was usually meticulous in his record-keeping. But this time it appeared he had simply collected the bones and dumped them at Wits.To find the Highland Giantrequired some detective work, digging up newspaper articles, and trying to identify landscapes from black-and-white photographs.The site was found on a steep mountainside close to the Lesotho border.Other pieces in the collection provide a glimpse of what is still out there to be found.A small box holds a number of serrated fangs. The longest is about 10cm long and was found at a 195million-year-old kill site.No one has an idea who or what this predator was."He would have shed teeth, just like sharks do," explained Choiniere.Palaeontologist Adam Yates, who found the tooth, named it Carnivore X.He said when he first saw the teeth he thought they were claws, until he noticed the serrations on the edges.He suspected that this shadowy meat-eater was probably about 8m-long and was a likely apex predator of its day...