Rare Namibian find turns existing theories about the Paleozoic Ice Age upside down
Last week, the Washington Post and Nature reported on a "giant stem tetrapod" (2.4m) that dramatically changes existing theories about the Permian period.The fossils indicate a sucker-feeder that could also catch larger prey.
According to the published study, current "hypotheses are based on a tetrapod fossil record that is almost exclusively restricted to paleoequatorial Pangaea".
The discovery of the giant stem tetrapod, Gaiasia jennyae, in Namibia, calls existing theories into question. The tetrapod is said to have occurred in the "high paleolatitude area" which the research team locates at about 55° south. They date the find to the early Permian period, "about 280 million years ago".
Gaiasia is represented by several large skeletons characterised by a weakly ossified skull with a loose palate, dominated by a broad parasphenoid and enlarged dentary and coronoid teeth. Phylogenetic analysis confirms that within the stem group of tetrapods, Gaiasia is the sister taxon to the Carboniferous Colosteidae from Euramerica.
Gaiasia is larger than all previously described digit-stem tetrapods and shows that continental tetrapods were well established in the cold-temperate latitudes of Gondwana during the Carboniferous-Permian deglaciation. This suggests a more global distribution of continental tetrapods during the Carboniferous-Permian transition and requires a reconsideration of previous hypotheses about the global turnover and dispersal of the tetrapod fauna.