They call it the “Highland Giant”. This dinosaur – which would have weighed about 10 tonnes and dwarfed its carnivorous relative the Tyrannosaurus Rex – roamed southern Africa about 200-million years ago, researchers say.

“This is the biggest dinosaur we have ever found,” says Dr Jonah Choiniere, a senior researcher in the Evolutionary Studies Institute at the University of Witwatersrand. This huge herbivore adds to the rich dinosaur fossil record contained in South Africa, which researchers are still trying to uncover.

Although the country’s early human ancestors have grabbed the public imagination, the region is also world-renowned for its rich dinosaur fossils.

But the story of this discovery begins with the Highland Giant’s thigh bone more than 20 years ago. “The discover of the giant femur dates back to over 20 years ago when the first part of this giant animals [was] found during excavations under the Caledon River for the Lesotho Highlands Water Project,” the university says.

Choiniere says that the femur remained in the university’s archives until his predecessor, dinosaur scientist Adam Yates, “saw the bones and said, ‘These were giants”. He went there and found other huge bones coming out of the cliff. He started excavating, but didn’t finish.”

Choiniere continued Yates’ work and “we’re [now] got bones from different parts of the anatomy, forelimb, hind limb, many from the vertebral column”.

However, the team has not named the dinosaur.

The fossil collection unveiled this week.
The fossil collection unveiled this week.

Most of the Highland Giant bones that they have discovered are still being prepared by technicians, he says. When fossil bones are discovered, they are usually still encased in rock and have to be separated from the rock, a process which Choiniere expects to take another six months.

“A thigh bone is a good way of estimating the size. We’re confident it weighs this much and know which part of the dinosaur tree it is on, but it is not a named species,” he says.

Asked why they had put parts of the Highland Giant on display, when so much was still unknown, Choiniere says: “It’s been 20 years since uncovering this thing. It is about time people knew what we were doing.

“The stuff on exhibit [at museums] is less than 1% of what is in our collection. It’s like an art museum [where most of the collection is not on display]. It is good to bring something up from the archive that usually only scientists see.”

Choiniere, who was a postdoctoral researcher at the American Museum of Natural History, says that he came to South Africa three years ago because of “the fossil record. They’re practically falling out of the side of the road, and no one knows about this.”

Fossils from the Highland Giant, as well as other specimens from the Wits’ fossil collection, are on display until January next year at the Kitching Gallery, which is adjacent to the Origins Centre.