Namibian discovery turns existing theories of late Palaeozoic ice age on its head

The Washington Post published an article this week about the &#039;giant stem tetrapod&#039;, which provides new insight into Earth&#039;s history and turns theories about the Permian age on their heads.“A study published in ‘Nature’ (nature.com) names the species Gaiasia jennyae - a salamander-like tetrapod, or four-legged vertebrate, that lived in what is now Namibia. Its eight-foot body is the largest tetrapod yet found with digits, and it had a broad, flat, diamond-shaped head and enlarged, interlocking fangs, the authors wrote. The fossils suggest it was a suction feeder that also had a powerful bite for capturing larger prey," wrote Frances Vinall of the Post.In the article published by Nature on 3 July, authors Claudia Marsicano, Jason Pardo, Roger Smith, Adriana Mancuso, Leandro Gaetano and Helke Mocke explain that the “current hypotheses of early tetrapod evolution posit close ecological and biogeographic ties to the extensive coal-producing wetlands of the Carboniferous palaeoequator with rapid replacement of archaic tetrapod groups by relatives of modern amniotes and lissamphibians in the late Carboniferous (about 307 million years ago).”The authors argue that “these hypotheses draw on a tetrapod fossil record that is almost entirely restricted to palaeo-equatorial Pangea.”.The discovery of the giant stem tetrapod, Gaiasia jennyae, in Namibia challenges existing theories.It is believed to have lived in high paleo-latitudes, which researchers place at about 55° South and date to the early Permian age, approximately 280 million years ago. Gaiasia is represented by several large, semi-articulated skeletons characterised by a weakly ossified skull with a loosely articulated palate, a broad diamond-shaped parasphenoid, a posteriorly projecting occiput, and enlarged, interlocking dentary and coronoid fangs.Phylogenetic analysis places Gaiasia within the tetrapod stem group as the sister taxon of the Carboniferous Colosteidae from Euramerica. Gaiasia is larger than all previously described digited stem tetrapods and provides evidence that continental tetrapods were well established in the cold-temperate latitudes of Gondwana during the final phases of the Carboniferous–Permian deglaciation, the researchers found. This suggests a more global distribution of continental tetrapods during the Carboniferous-Permian transition, requiring a reconsideration of previous hypotheses regarding global tetrapod faunal turnover and dispersal.

Namibian discovery turns existing theories of late Palaeozoic ice age on its head

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Republikein 2025-04-07

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Namibian discovery turns existing theories of late Palaeozoic ice age on its head

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