The ammonite genus Nigericeras Schneegans, 1943, generally placed in the ammonite family Vascoceratidae,belongs to the Acanthoceratinae, and resemblance to vascoceratids is homeomorphy, rather than an indication of affinity. Vascoceratidae and Pseudotissotiidae are separate families rather than the latter being a subfamily of the former, within the Acanthocerataceae. © 1994.
