Lotharingibelus n. gen., a new belemnite genus from the upper Toarcian Minette ironstones of the NE Paris Basin

Jurassic belemnites have been widely studied by pioneering paleontologists in the early to late 19th century; it is therefore not surprising that most taxa still valid today were originally erected during that century. However, the standards for description and figuration having considerably evolved since then, many “historical” taxa have been repeatedly the subject of diverging taxonomic interpretation. It is therefore of great importance to revise these taxa and provide more detailed descriptions and illustrations of the type material. Herein, we restudy abundant material of Belemnites meta Blainville, 1827 and Belemnites subgiganteus Branco, 1879, two characteristic belemnite taxa of the Minette-type ironstones of Lorraine (France, Region Grand-Est, departments Moselle and Meurthe-et-Moselle), southern Luxembourg and Gaume (Southeast Belgium). Over the years, the taxonomic interpretation and species boundaries of these two taxa have remained unclear, with diverging opinions. We therefore maintain that for the purposes of a precise application of these nominal species and to clarify their stratigraphic position, systematic characters, and phylogenetic relationship, a typification is necessary. Herein, we designate a neotype for B. subgiganteus, illustrate the types of both species, and provide details about their type localities and stratigraphic occurrence. Their peculiar morphological characters also lead us to introduce a new genus, Lotharingibelus n. gen., with Belemnites meta Blainville as a type species. Lotharingibelus n. gen. is a megateuthidid with a relatively short stratigraphical range (upper Toarcian) that had its dispersal center in the north-eastern Paris Basin. The occurrence of specimens with or without an epirostrum allows us to discuss aspects of their ontogeny and the long-debated issue of a possible sexual dimorphism in belemnites.