Article: The Yorkshire type ammonites and nautiloids of Young and Bird, Phillips, and Martin Simpson

The work of figuring and interpreting the Yorkshire Mesozoic ammonite species of Young and Bird, Phillips, and Martin Simpson started by Buckman in his well-known Yorkshire Type Ammonites is completed and critically revised. In addition to the Jurassic ammonites dealt with by Buckman, the nautiloids and Cretaceous ammonites are also figured and interpreted, as well as the remaining Jurassic ammonites. The type specimens of 38 species are figured, many of them for the first time. Of the 225 specific names proposed by the four Yorkshire authors, 188 can now be interpreted from figured type specimens, and out of the 37 remaining, 27 have no type specimens and cannot be interpreted with sufficient accuracy to be of use or to be put in synonymy. It is emphasized that all the specific names are valid according to the Rules of Nomenclature from the date of their original proposal, and the authenticity of their type specimens is established in each case.