What is "melanosteus"

Melanosteus occitanus is a small (skull about 5 centimeters long) selenosteid arthrodire placoderms known from the Upper Frasnian Montagne Noire of Southern France. Rücklin (2011), regards M. occitanus as the sister taxon of Rhinosteus. During the Frasnian, M. occitanus lived off the coast of an island continent, "Armorica," which consisted of portions of what would become Southern France.