The tornoceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea) Author Korn, Dieter 304FF76E-83FB-478C-AAA9-BD5769C80918 Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstrasse 43, D- 10115 Berlin, Germany. dieter.korn@mfn.berlin Author Bockwinkel, Jürgen 1F1EDD42-B1CE-425C-9CBD-D19658A6C453 Dechant-Fein-Strasse 22, D- 51375 Leverkusen, Germany. jbockwinkel@t-online.de text European Journal of Taxonomy 2022 2022-03-21 806 32 51 http://zoobank.org/a2b2a310-8c8c-41b0-b934-1666129b7d90 journal article 20137 10.5852/ejt.2022.806.1699 ee706a5b-3456-4097-b44d-2ebfd40a0824 2118-9773 6373961 A2B2A310-8C8C-41B0-B934-1666129B7D90 Genus Tornoceras Hyatt, 1884 Type species Goniatites uniangularis Conrad, 1842 ; by original designation. Diagnosis Genus of the subfamily Tornoceratinae with compressed conch, umbilicus closed in the pre-adult stage but slightly opened in the juvenile stage. Usually without ventrolateral grooves. Growth lines biconvex, without ribs. Sutural formula E A L I; adventive lobe broadly rounded, asymmetric with steep dorsal flank. Included species Tornoceras aequilobum Söte, Becker, Herd & Bockwinkel, 2021 , Rhenish Mountains; Tornoceras ( Tornoceras ) uniangulare var. aldanense House, 1965 , New York; Tornoceras ( Tornoceras ) amuletum House, 1965 , New York; Tornoceras simplex Mut. angustelobata Holzapfel, 1895 , Rhenish Mountains; Tornoceras ( Tornoceras ) arcuatum House, 1965 , Michigan; Tornoceras ( Tornoceras ) arkonense House, 1965 , Ontario; Goniatites Astarte Clarke, 1885 , New York; Tornoceras baldisi Leanza, 1968 , Argentina ; Tornoceras Bertrandi Frech, 1902 , Montagne Noire; Tornoceras ( Tornoceras ) bolivianum Kullmann, 1980 , Bolivia ; Tornoceras uniangulare var. compressum Clarke, 1899: 116 ; New York; Tornoceras ( Tornoceras ) concentricum House, 1965 , New York; Tornoceras ( Tornoceras ) contractum Glenister, 1958 , Western Australia; Tornoceras Edwin -Halli Clarke, 1899, New York; Tornoceras Frechi Wedekind, 1918 , Rhenish Mountains; Tornoceras fundibulum Korn, 2021 , Rhenish Mountains; Linguatornoceras holwilli House, 2002 , Devon; Goniatites Hughesii Whidborne, 1890 , Devon; Tornoceras ( Tornoceras ) iowaense Miller, 1938 , Iowa; Gomi -monomeroceras ( Tornoceras ) kielcense Sobolev, 1914, Holy Cross Mountains; Tornoceras Lewinskii Dybczynski, 1913 , Holy Cross Mountains; Tornoceras uniangulare var. obesum Clarke, 1899 , New York; Tornoceras occasus Korn, 2021 , Anti-Atlas; Tornoceras ortus Korn, 2021 , Anti-Atlas; Tornoceras postsimplicius Pajchlowa, 1972 ; Tornoceras radialis Becker, 1993 , Rhenish Mountains; Tornoceras subacutum Makowski, 1991 , Holy Cross Mountains; Gomi - monomeroceras ( Tornoceras ) sublentiforme Sobolev, 1914, Holy Cross Mountains; Goniatites retrorsus var. typus Sandberger & Sandberger, 1851 , Rhenish Mountains; Goniatites uniangularis Conrad, 1842 , New York; Tornoceras varicatum Grüneberg, 1925 , Rhenish Mountains; Tornoceras Verae Frech, 1902 , Montagne Noire; Tornoceras vretterense Korn, 2021 , Rhenish Mountains; Tornoceras Whidbornei Foord & Crick, 1897 , Devon; Tornoceras ( Tornoceras ) uniangulare var. widderi House 1965 , Ontario; Tornoceras wunderlichi Bockwinkel & Korn, 2015 , Rhenish Mountains; Remarks Tornoceras is a genus that has long been used as a taxon to group together most involute Late Devonian ammonoids with a simple suture line. Even after the revisions by House (1965) and Becker (1993) and their separation of a number of new genera, there is a long list of species assigned to the genus ( Korn & Klug 2002 ). Most of these species are morphologically very similar and a detailed description of the ontogenetic development of the conch is lacking. A revision of the genus would require a careful description of the ontogeny, suture lineage and growth lineage of the material from the different geographical regions and stratigraphic units ( Korn 2021a ).