The presumed hagfish Myxineidus gononorum from the Upper Carboniferous of Montceau-les-Mines (Saône-et-Loire, France): New data obtained by means of Propagation Phase Contrast X-ray

a b s t r a c t The re-examination of the presumed hagfish Myxineidus gononorum from the Carboniferous of Montceau- les-Mines by means of propagation phase contrast X-ray synchrotron microtomography confirms the presence of two series of non-mineralized denticles arranged in chevrons in the oral region. It also indi- cates the presence of possible traces of post-mortem mineralized soft tissues. A peculiar zone of less X ray-absorbing matter around the animal suggests the presence of an enlarged, lamprey-like oral disc. Re-interpreting Myxineidus as a lamprey would be in better agreement with the reputedly fresh-water environment of the Montceau-les-Mines Lagerstatte.