The type (and only known) specimen of Melbournopterus crossotus Caster & Kjellesvig-Waering, an enigmatic late Silurian fossil that was initially assigned to the eurypterid family Stylonuridae, is critically examined for the first time in 60 years. It is reinterpreted as most likely the dorsal valve of a craniate brachiopod, with prominent paired adductor muscle scars (described originally as 'lateral eyes') situated anteromedially, a short hingeline and a spinose anterior margin. James C. Lamsdell [email@example.com], Department of Geology and Paleontological Institute, University of Kansas, 1475 Jayhawk Boulevard, Lawrence, KS 66045, USA; Ian G. Percival [firstname.lastname@example.org], Geological Survey of New South Wales, W.B. Clarke Geoscience Centre, 947-953 Londonderry Road, Londonderry NSW 2753, Australia; Markus Poschmann [email@example.com], Generaldirektion Kulturelles Erbe RLP, Direktion Landesarchäologie, Referat Erdgeschichte, Große Langgasse 29, D-55116 Mainz, Germany. Received 12.10.2012; revised 13.12.2012; accepted 26.12.2012.
- late Silurian