Dehmicystis globulus, an enigmatic solute (Echinodermata) from the Lower Devonian Hunsruck Slate, Germany

Dehmicystis globulus is a very poorly known Lower Devonian solute echinoderm from the Hunsruck Slate of Germany. To date, only the holotype has been formally described; however, it is incomplete and does not preserve important characters of the group. We report three new individuals on the same slab of slate, one of which is almost complete. This material informs a full systematic redescription of the genus. The orientation and mode of life of solutes are contentious; our new morphofunctional data strongly suggest that Dehmicystis was oriented with the ambulacrum on the upper surface. Such a position implies a suspension feeding mode of life, with food particles captured from the current using the ambulacrum. The stele may have enabled limited movement on the sea floor but was principally responsible for support, anchorage, and (facultative) attachment.