Oldest southern continent animal unearthedThe oldest land animal to have been discovered from the an

Oldest southern continent animal unearthedThe oldest land animal to have been discovered from the ancient southern continent of Gondwana has just been reported in the journal African Invertebrates. It dates from around the late Devonian or early Carboniferous, 360 million years ago. At the time, most of Earth’s landmass was partitioned over two supercontinents - the northernmost, Laurasia, straddled the equator while Gondwana sat at the south pole.It is thought that plant life first colonised land in the Ordovician period, 450 million years ago. Then, during the Siluran, and it is thought that the first animals began to move from sea to land. They were simple compost-generating invertebrates - primitive insects and millipedes. They in turn were followed by more complex animals, like scorpions. Evidence is that scorpions moved from the oceans onto land (terrestrialisation) during the Devonian, and a few fossilised examples of Devonian scorpions have previously been reported, but all from rocks that were part of Laurasia. This is not so surprising. Scorpions today live in warm environments, and are not generally found at high latitudes (although some do exist in Patagonia).The Gondwana scorpion (which has been named Gondwanascorpio emzantsiensis), was found by Dr Robert Gess from Wits University, Johannesburg, in 360 million year old Devonian Witteberg Group rocks near Grahamstown. These were part of Gondwana back then, separated from Laurasian by the deep Tethys ocean. “Evidence on the earliest colonisation 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,” says Dr Gess.The finding demonstrates that there were scorpions living in high latitude Gondwana, the earliest animals found there thus far, but also implies a terrestrial ecosystem with prey for them to feed upon. The latitudes are higher even than the habitats of the modern day Patagonian scorpions.It seems that the lack of Gondwana animal fossils is as much a feature of the lack of sedimentation, and hence burial and preservation, later during the Carboniferous as lack of organisms. At that time southern Africa, the location of the fossil find, was slowly wandering across the south pole, with much of the landmass glaciated. But Gess’s find demonstrates that there were terrestrial ecosystems in place, and (like Laurasia) animal life was likely diversifying across the southern continent.~SATR (follow me on twitter @sim0nredfern)Image: the sting of Gondawanascorpio, about 2 cm long. (Credit: Dr Robert Gess)Original paper: http://africaninvertebrates.org/ojs/index.php/AI/article/view/284 -- source link
Tumblr Blog : the-earth-story.com

More pics about