A 350-million-year-old scorpion has been described as the oldest land-dwelling animal ever discovered on Gondwana, the more southerly of two supercontinents which made up Earth's land area when the world was compacted into Pangea.
The find is remarkable as it is first time a predatory, land-dwelling invertebrate like a scorpion has been found on ground that once composed the Gondwana landmass. Prior to this find, such evidence of terrestrialisation -- the movement of life from sea onto land -- was only known on Laurasia, the northerly of the two Pangea-era supercontinents. Today, Laurasia has broken apart into North America and Asia, while Gondwana included present-day Africa, Australia and South America.
"Evidence on the earliest colonization of land animals has up till now come only from the northern hemisphere continent of Laurasia, and there has been no evidence that Gondwana was inhabited by land living invertebrate animals at that time," said Robert Gess a postdoctoral fellow at Wits University's Evolutionary Studies Institute, referencing the Devonian Period where life moved out from water onto a land full of plant life.
Fossilized scorpion fragments -- with a pincer and a sting clearly showing in the rock -- were found near Grahamstown in South Africa's Eastern Cape.
Gess named the new species Gondwanascorpio emzantsiensis.
"For the first time we know for certain that not just scorpions, but whatever they were preying on were already present in the Devonian. We now know that by the end the Devonian period Gondwana also, like Laurasia, had a complex terrestrial ecosystem, comprising invertebrates and plants which had all the elements to sustain terrestrial vertebrate life that emerged around this time or slightly later," Gess said.
Gess' discovery has been published in the peer reviewed journal African Invertebrate.