Paleontologists have discovered a new species of long-necked, plant-eating dinosaur that roamed southern Africa 200 million years ago when it was still part of the supercontinent Gondwana. The medium-sized new species was a transitional form that lived before the famous, gigantic sauropods like Diplodocus and the recently revived Brontosaurus. It's described in the Zoological Journal of the Linnean Society this week.
The fossils were unearthed in the 1930s from the Upper Triassic−Lower Jurassic Elliot Formation of South Africa about 30 kilometers from the Lesotho border. However, it was only recently rediscovered among the thousands or so fossils in the University of the Witwatersrand collection. An international team led by Alejandro Otero from Argentina’s Museo de La Plata examined the fossils -- including multiple vertebrae, most of a forelimb, and part of a hindlimb -- representing at least four individuals.
At first, they thought the bones belonged to a known South African dinosaur named Aardonyx, but with closer scrutiny, it turned out to be the previously unknown early sauropodomorph -- early members of the group that gave rise to the later long-necked giants of the Mesozoic. One of its ankle bones, called the astragalus, was especially unique: It’s shaped like a cross. So, they named it Sefapanosaurus zastronensis, from the local Sesotho word “sefapano” for “cross.”
The new dino helps fill in an important gap. “Sefapanosaurus constitutes a member of the growing list of transitional sauropodomorph dinosaurs from Argentina and South Africa that are increasingly telling us about how they diversified,” Otero explains in a statement. The two continents were both part of a single, southern hemisphere landmass at the time.
Study coauthor Emil Krupandan from the University of Cape Town adds: “This find indicates the importance of relooking at old material that has only been cursorily studied in the past, in order to re-evaluate past preconceptions about sauropodomorph diversity in light of new data.”