SOLUTION TO THE HALLOPUS ENIGMA

For some unknown reason, the original source of the still unique type specimen (YPM 1914) of the fossil reptile Hallopus victor was never re vealed by its author, O. C. Marsh (1877). Whether out of ignorance or by deliberate design, Marsh never revealed either the geographic local ity or the stratigraphic provenance of this specimen despite (or becau se of) the importance he apparently attached to it. Past attempts to l ocate and date its source have been unconvincing. Here, we submit a pr obable resolution to this century-long enigma.