Meet the grandparent of the Brontosaurus

The largest vertebrates to ever walk the Earth were doing so as far back as the Early Jurassic period, more than 200 million years ago, South African researchers have discovered.

A 12-tonne dinosaur skeleton found on the border of South Africa and Lesotho is one of the first four-limbed sauropods, and an older relative of the universally known but often misunderstood Brontosaurus.

However, the newly discovered giant herbivore had yet to develop the Brontosaurus’s columnar, elephant-like legs, so it likely had flexed or crouched legs.

“The evolution of sauropods isn’t quite as straightforward as we once thought,” says palaeontologist Jonah Choiniere from the University of the Witwatersrand in Johannesburg.

“In fact, it appears that sauropodomorphs evolved four-legged postures at least twice before they gained the ability to walk with upright limbs, which undoubtedly helped make them so successful in an evolutionary sense.”

The Brontosaurus lived between the Late Jurassic and the Early Cretaceous periods, 163.5 million to 100.5 million years ago.

The researchers believe the South African skeleton is of a fully-grown adult, about 14 years old. They have named it Ledumahadi mafube – “a giant thunderclap at dawn” in the local Sesotho language.

Choiniere says the findings, published in the journal Current Biology, provide further evidence that “there was a thriving dinosaur ecosystem here in South Africa” millions of years before the Tyrannosaurus or Velociraptor came on the scene in the northern hemisphere.

“Africa, and particularly South Africa, is known for its big game,” he says. “I think we should be just as famous for our big game of the early Mesozoic, 200 million years ago.”