Cape Town – The earliest evidence of land animals on the ancient southern supercontinent of Gondwana has been found in the Eastern Cape.
It includes a fossilised pincer as well as part of the tail and sting from a species of 360 million-year-old scorpions.
They lived during a geological period known as the Devonian.
The small, predatory creatures, which would have snacked on the world’s first primitive insects and millipedes, were almost the length of a modern-day pencil.
Dubbed Gondwanascorpio emsantsiensis by its discoverer Dr Robert Gess, a researcher at the time with the Bernard Price Institute of Palaeontological Research, details of the new species have been published in the latest volume of the scientific journal, African Invertebrates.
The tiny fossils were found compressed between layers of shale taken from a road cutting near Grahamstown.
“They are very delicate, and silvery-white in colour against the dark background of the rock,” Gess told Sapa.
He said the pincers and the tail segment and sting were found separately, and were not from the same individual.
He had found both fossils while carefully splitting apart small slabs of shale from the site, and was “totally thrilled” by the discovery.
“One knows one’s found something very significant,” he said.
Back in the Devonian, between 420 and 360 million years ago, the world consisted of two supercontinents: Laurasia, comprising North America, Europe and Asia; and the southerly Gondwana, including Africa, South America, Australia, Antarctica and India.
The two were separated by a deep ocean.
Gess said that although it was known that Laurasia was inhabited by diverse invertebrates before and during the Devonian, “until now, we had no evidence that the early plant life of Gondwana was similarly inhabited”.
For the first time, it was now known that not just scorpions, but whatever they were preying on were already present in the Devonian.
“We know now that Gondwana, like Laurasia, had a complex terrestrial ecosystem, comprised of invertebrates and plants, by the end of the Devonian.
“It too, therefore, had all the elements to sustain terrestrial vertebrate life that emerged around this time, or slightly later,” he said.
Among other fossils found by Gess in rocks from the Eastern Cape site are 20 types of fish and a range of different land plants.
At the time these existed, the area was on the edge of a high latitude coastal lagoon.