Lund 1982. Harpagofututor volsellorhinus new genus and species (Chondrichthyes, Chondrenchelyiformes) from the Namurian Bear Gulch Limestone, Chondrenchelys problematica Traquair (visean), and their sexual dimorphism. Journal of Paleontology, 56(4) 1982: 938-958