Holotype of Baculites perplexus (USNM 108914). Original unmodified images provided by courtesy of the Smithsonian NMNH and adapted and presented here under a Creative Commons BY-NC 4.0 license (http://n2t.net/ark:/65665/369504f43-68cd-4abd-9eac-61f26a9b0fd6).Baculites perplexus from the Pierre Shale (Mitten Black Shale Member) of Niobrara County, Wyoming (YPM IP 201993).