What is "entelognathus"

Entelognathus primordialis (“primordial complete jaw”) is a placoderm from the late 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.