New study showing pelvic girdles arose before the origin of movable jaws

Almost all gnathostomes or jawed vertebrates (including osteichthyans, chondrichthyans, ‘acanthodians’ and most placoderms) possess paired pectoral and pelvic fins. To date, it has generally been believed that antiarch placoderms (extinct armoured jawed fishes from the Silurian–Devonian periods) lacked pelvic fins. As Parayunnanolepis xitunensis with extensive post-thoracic preservation represents the only example of a primitive antiarch, and its original description has been cited as confirming the primitive lack of pelvic fins in early antiarchs.

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