Enigmatic placoderm taxa

Entelognathus primordialis (“primordial complete jaw”) is an early placoderm from the late Silurian (Ludlow epoch) of Qujing, Yunnan, 419 million years ago. A team led by Min Zhu of the Academy of Sciences' Institute of Vertebrate Paleontology and Paleoanthropology in Beijing discovered the intact, articulated fossil in rock formations at Xiaoxiang reservoir.