THE FOSSIL remains of a hitherto unknown species of dinosaur that is being hailed as the missing link between prehistoric two-legged animals and those that walked on four legs has been discovered in South Africa.
The researchers found the remains of two juvenile skeletons of the newly named Aardonyx celestae, a heavy, slow-moving herbivore that lived near Senekal in the northern Free State province around 950 million years ago. The Aardonyx, which had short, broad feet and a big midriff, was at least 7m long and as tall as a 6ft man even when juvenile.
At a press conference on Wednesday Dr Adam Yates, the lead scientist from Johannesburg’s University of Witwatersrand, who unearthed the find, told reporters the discovery was hugely important.
“What we have is a big, short-footed, barrel-chested, long-necked, small-headed dinosaur. The earliest ancestral dinosaur – the great grand-daddy of all dinosaurs – walked on two legs. This [one] is intermediate between those bipedal forms and the true gigantic sauropods,” he said.
The scientist’s findings regarding the remains, which were first discovered five years ago, were published in the Proceedings of the Royal Society journal this week, after other scientists critically reviewed their work and assertions.
The dinosaurs were found at a site in the Free State called Marc’s Quarry, and the area is believed to have been a prehistoric oasis where a number of mysterious animals, including a meat-eater currently known as Carnivore X, once roamed in great numbers.
“It was probably a well-watered area in a dry floodplain. To feed such animals you would need to have had quite a large volume of plants. So, at the time, it was a living fossil – the transition must have happened much earlier,” explained Dr Yates.
He stressed that the site where the fossil was discovered provided an abundance of valuable knowledge about dinosaur evolution. “If you want to study how the dinosaurs became giants,” he said, “you have to come to South Africa.”
Because of the lush vegetation, and giant herbivores found at the site, big carnivores would have come along to fill a niche in the food chain, according to Dr Yates, who added that the carnivore left clues of its existence in the form of several 10cm-long teeth.
“When we first found them, we thought they were claws, but then we noticed the serrated edges and we knew they were teeth,” he said.
Dr Yates guessed the carnivore was probably “seven to eight metres in length, about the size of a small T Rex, which is huge for this period”. Two other new species of herbivore, which are in the process of being named, have also been found by Dr Yates and his team.
Although the Free State site that provided the skeletal remains of the Aardonyx has been emptied of fossils, another bone field has been discovered close by. Dr Yates and his team want to explore it in the hope of finding more new species.