2022/11/03 by Volker Dietze, Günter Schweigert, Robert B. Chandler · 1 citation
Earth and Planetary Sciences · Agricultural and Biological Sciences · #Paleontology and Stratigraphy of Fossils #Mollusks and Parasites Studies #Geology and Paleoclimatology Research
paper · pdf · doi:10.18476/pale.v15.a8
openalex publication_date 2022/11/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/02
New specimens of the rare ammonite genus Diplesioceras Buckman, 1920 from the Upper Bajocian of Normandy and from the Iberian Ranges of Spain provide additional information on the shell morphology and ontogeny of this previously monotypic genus. A new species of Diplesioceras, D. fischeri, is recorded by a single specimen probably originating from the Parkinsoni Zone. The new material clearly demonstrates the presence of a vertically undulating floored keel, a character previously only known from some Strigoceratidae Buckman, 1924. This observation let us to discuss whether Diplesioceras should be assigned to Strigoceratidae Buckman, 1924. Further characters such as ribbing style and conch ontogeny, intraspecific variation, biostratigraphic occurrence and palaeogeographic distribution were analyzed. Despite of a long stratigraphical gap to supposedly ancestral taxa, a systematic placement of Diplesioceras in Hammatoceratidae Buckman, 1887 appears to be more convenient; however, we cannot exclude an origination in Strigoceratidae either.