A multinational team of paleontologists has discovered the remains of a new species of sauropodomorph dinosaur that roamed what is now South Africa at the beginning of the Jurassic period, 200 million years ago.

The specimen, now named Sefapanosaurus zastronensis, was found in the 1930s in the Upper Triassic-Lower Jurassic Elliot Formation near the town of Zastron, in the Free State Province of South Africa, about 30 km west of the Lesotho border.

A few years ago it was studied and considered to represent the remains of another South African dinosaur, Aardonyx.

However, upon further study, close scrutiny of the fossilized bones has revealed that it is a completely new species of dinosaur.

Sefapanosaurus zastronensis is among the early members of the group that gave rise to the later long necked giants of the Mesozoic.

“The medium-sized dinosaur is a member of the growing list of transitional sauropodomorph dinosaurs from Argentina and South Africa that are increasingly telling us about how they diversified,” said Dr Alejandro Otero of the CONICET in La Plata, Argentina, and the University of the Witwatersrand in Johannesburg, lead author on the study published in the Zoological Journal of the Linnaean Society.

“Sefapanosaurus zastronensis helps to fill the gap between the earliest sauropodomorphs and the gigantic sauropods,” he added.

According to the team, one of the most distinctive features of Sefapanosaurus zastronensis is that one of its ankle bones, the astragalus, is shaped like a cross.

“This new animal shines a spotlight on southern Africa and shows us just how much more we have to learn about the ecosystems of the past, even here in our own backyard,” said study senior author Dr Jonah Choiniere of the University of the Witwatersrand.

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Alejandro Otero et al. 2015. A new basal sauropodiform from South Africa and the phylogenetic relationships of basal sauropodomorphs. Zoological Journal of the Linnean Society, vol. 174, no. 3, pp. 589-634; doi: 10.1111/zoj.12247