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Judi Lynn

(161,903 posts)
Thu Sep 29, 2022, 10:58 PM Sep 2022

Ancient 'sharks' appeared much earlier than previously thought

The first appearance of shark-like ‘jawed fish’ may have happened some 15 million years earlier than previously thought, according to new evidence.

Published today



Fanjingshania renovata. Credit: Heming Zhang

A handful of fossil teeth from a completely new species, uncovered from rock samples found in China, suggest jawed fish emerged some time at the end of the Ordovician, or beginning of the Silurian period, around 440 million years ago.

Previously, the earliest jawed fish to be positively identified, included species from the upper Silurian era, 424 million years ago. These include the placoderms, a partially armoured species, and sarcopterygians, a bony ‘lobe-finned’ species found initially in China and Vietnam.

The fossil samples were found and analysed by researchers at the University of Birmingham, in the UK, the Institute of Vertebrate Paleontology and Paleoanthropology, part of the Chinese Academy of Sciences and Qujing Normal University (QJNU), China. The results are published today [28 September 2022] in Nature.



Fanjingshania renovata. Credit: Heming Zhang

“Until this point, we’ve picked up hints from fossil scales that the evolution of jawed fish occurred much earlier in the fossil record, but have not uncovered anything definite in the form of fossil teeth or fin spines” said Dr Ivan Sansom, lecturer at the University of Birmingham and a co-author on the paper.

More:
https://www.birmingham.ac.uk/news/2022/ancient-sharks-appeared-much-earlier-than-previously-thought

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