Cainozoic Research, 16(2), pp. 109-219, December 2016 109 The lower Pliocene gastropods of Le Pigeon Blanc (Loire- Atlantique, north west France), 2. Caenogastropoda* Frank Van Dingenen1, Luc Ceulemans2 & Bernard M. Landau3, 4 1 Cambeenboslaan A 11, B-2960 Brecht, Belgium; email: [email protected] 2 Avenue Général Naessens de Loncin 1, B-1330 Rixensart, Belgium; email: [email protected] 3 Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA Leiden, Netherlands; Instituto Dom Luiz da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; and International Health Centres, Av. Infante de Henrique 7, Areias São João, P-8200 Albufeira, Portugal; email: [email protected] 4 Corresponding author Received 1 June 2016, revised version accepted 20 September 2016. In this paper we review the Caenogastropoda of the Zanclean lower Pliocene assemblage of Le Pigeon Blanc, Loire-Atlantique department, which we consider the ‘type’ locality for Assemblage III of Van Dingenen et al. (2015). Ninety-one species are recorded, of which 17 are new: Bittium lozoueti nov. sp., Bittium gliberti nov. sp., Tympanotonos redoniensis nov. sp., Oligodia palumbina nov. sp., Cochlis robbai nov. sp., Cochlis pedrialii nov. sp., Payraudeautia pigeonblancensis nov. sp., Alvania calasi nov. sp., Alvania dissensia nov. sp., Alvania merlei nov. sp., Alvania zbyszewskii nov. sp., Crisilla ariejansseni nov. sp., Rissoa pouweri nov. sp., Caecum aartseni nov. sp., Nystia guillotini nov. sp., Aclis pacaudi nov. sp., Niso dollfusi nov. sp. This includes the first European Neogene record for the genus Tympanotonos. Macromphalina bouryi (de Morgan, 1915) is a secondary homonym of Macromphalina bouryi (Dautzenberg, 1912) and renamed Macromphalina massicardi nom. nov. Based on the data presented here, we suggest that average Sea Surface Temperatures off the NW French coast in the Zanclean early Pliocene may have been warmer than they are at these latitudes today, possibly similar to those found today off the southern Portuguese coasts. Key words: northwestern France, lower Pliocene, Caenogastropoda, new taxa Introduction Geological setting and Material and methods In this paper we continue our studies on the Neogene (see Ceulemans et al., 2016, pp. 51-52). gastropod fossil assemblages of northwestern France (see Ceulemans et al., 2014, 2016; Van Dingenen et al., 2014, Abbreviations: 2015). Gastropods of the subclass Caenogastropoda are revised, and the study is restricted to the locality of Le MNHN.F Muséum national d’Histoire naturelle (collec- Pigeon Blanc, which we consider to be the ‘type locality’ tion de Paléontologie), Paris (France). for Assemblage III of Van Dingenen et al., 2015. NHMW Naturhistorisches Museum Wien collection, In his unpublished thesis, Brébion (1964) of the Centre Vienna (Austria). National de la Recherche Scientifique, Paris, recorded 42 FVD Frank Van Dingenen private collection, Brecht Caenogastropoda species from Le Pigeon Blanc, some of (Belgium). which were described as new. However, as the thesis was LC Luc Ceulemans private collection Rixensart never published, these names do not comply with arti- (Belgium). cle 13 of the ICZN code (1999) and must be considered nomina nuda. * For nr 1 in this series see Ceulemans et al. (2016), Cainozoic Research 16(1): 51-100. For nr 3 in this series see Ceulemans, L., Van Dingenen, F., Merle, D. & Landau, B.M. 2016. The lower Pliocene gastropods of Le Pigeon Blanc (Loire-Atlantique, northwest France). Part 3 – Muricidae. Vita Malacologica 15: 35-55. Correction: In part 3 of this series, p. 45 paratype 1 of Ocinebrina lauriatrageae numbered A35352, should read A57352. 110 Van Dingenen, Ceulemans & Landau. The lower Pliocene gastropods of Le Pigeon Blanc. Caenogastropoda Systematic palaeontology Brébion (1964) stressed the enormous variability in the material he had at hand and pointed out that some NW Subclass Caenogastropoda Cox, 1960 French specimens were larger than those from the Para- Superfamily Cerithioidea Fleming, 1822 tethys, and concluded that it was not easy to character- Family Cerithiidae Fleming, 1822 ise T. bronni. However, if the Atlantic form should turn Subfamily Cerithiinae Fleming, 1822 out to be distinct from that of the Paratethys, the name Genus Thericium Monterosato, 1890 Cerithium inconditum Millet, 1865 has priority over Ce- rithium heptagonum Mayer-Eymar, 1889, at least for the Type species (by original designation) – Cerithium vul- Assemblage I populations. gatum Bruguière, 1792, present-day, Mediterranean. Based on the scant and imperfectly preserved material from Le Pigeon Blanc, we echo Brébion’s conclusion. 1890 Thericium Monterosato, p. 163. Each of the fragments at hand varies slightly in spiral 1895a Vulgocerithium Cossmann in Sacco, p. 77. Type angle, sculpture, number of axial ribs and their develop- species (by subsequent designation, Cossmann, ment. We also agree with the above authors that we can- 1906): Cerithium vulgatum Bruguière, 1792, not separate them from the Paratethian shells. present-day, Mediterranean. Brébion (1964, p. 241) recorded this species from Assem- blage I localities (Sceaux-d’Anjou, Thorigné, St-Michel, Chalonnes, Reneauleau, Beaulieu) and Assemblage III Thericium bronni (Hörnes, 1856) (Le Pigeon Blanc, Palluau). The latter Zanclean records Plate 1, figs 1-3 are the stratigraphically earliest for the species. 1854 Cerithium Inconditum Millet, p. 163 (nomen nu- Distribution – Lower Miocene: Atlantic (Burdigalian), dum). Aquitaine Basin, France (Vignal, 1911; Cossmann, 1906; *1856 Cerithium Bronni Partsch, Hörnes, p. 407, pl. 42, Cossmann & Peyrot, 1921); Proto-Mediterranean, Italy fig. 12. (Sacco, 1895a). Middle Miocene: Atlantic, Loire Basin, 1865 Cerithium inconditum Millet, p. 594. France (Glibert, 1949), Aquitaine Basin, France (Coss- 1889 Cerithium heptagonum Mayer-Eymar, p. 207, pl. mann & Peyrot, 1921); Paratethys, Austria (Hörnes, 1856; 5, fig. 7. Schultz, 1998). Upper Miocene: Atlantic (Tortonian), 1895a Cerithium (Ptychocerithium) Bronni var. tauro- NW France (Brébion, 1964). Lower Pliocene: Atlantic, planata Sacco, p. 26, pl. 2, figs 43, 44. NW France (Brébion, 1964). 1895a Cerithium (Ptychocerithium) Bronni var. transiens Sacco, p. 26, pl. 2, fig. 45. 1906 Cerithium (Ptychocerithium) Bronni Partsch – Coss­­ Genus Colina H. Adams & A. Adams, 1854 mann, p. 81, pl. 4, fig. 2. 1911 Cerithium (Ptychocerithium) Bronni Partsch – Vig- Type species (by subsequent designation, Cossmann, nal, p. 148, pl. 7, fig. 8. 1889) – Cerithium macrostoma Hinds, 1844, present-day, 1921 Cerithium (Ptychocerithium) heptagonum (Mayer- Indonesia. Eymar) – Cossmann & Peyrot, p. 204, pl. 5, figs 74, 75. 1854 Colina H. Adams & A. Adams, p. 286. 1949 Cerithium (Ptychocerithium) bronni heptagonum Mayer, 1889 – Glibert, p. 147, pl. 9, fig. 11. Note – At Le Pigeon Blanc, material ascribed to the 1964 Cerithium (Ptychocerithium) bronni Partsch in genus Colina H. Adams & A. Adams 1854 by Brébion Hörnes, 1845 – Brébion, p. 239, pl. 6, figs 16-20. (1964) is fragmentary. In the Assemblage I localities 1998 Cerithium (Ptychocerithium) bronni Partsch – this material is more plentiful and better preserved. Schultz, p. 58, pl. 22, fig. 2. Whether these NW French Atlantic Miocene and Pliocene species are monophyletic with the present-day Material and dimensions – Maximum height 28.4 mm (all Cerithium macro stoma Hinds, 1844, type species of the incomplete). NHMW 2015/0133/0203-0205 (3), NHMW genus Colina, is doubtful. Some of the French speci- 2015/0133/0103 (4); LC (10); FVD (12). Le Pigeon Blanc, mens have strongly varicose later adult whorls, which Le Landreau, Nantes area, Loire-Atlantique department, distort the shell and sculpture. It is also possible that NW France. these shells are not members of the Cerithiidae Flem- ing, 1822, but Cerithiopsidae Forbes & Hanley, 1850, Discussion – Cossmann & Peyrot (1921) separated the as the sculpture is also similar to that of members of Atlantic lower and middle Miocene specimens under the the genus Krachia Bałuk, 1975 (see Bouchet & Warén, name Cerithium (Ptychocerithium) heptagonum from 1993, p. 605). We hope that the better preserved material Thericium bronni (Hörnes, 1856) based on the shells be- from Assemblage I will have the protoconch preserved, ing smaller, thinner and more elongated, and on small which would help us place these shells. Provisionally sculptural details. Glibert (1949) considered them a sub- they are recorded here, but will be discussed and com- species of T. bronni, the only constant difference between pared in more detail in the paper covering Assemblage them being the smaller size of the Atlantic specimens. I localities. Cainozoic Research, 16(2), pp. 109-219, December 2016 111 Colina jucunda (Millet, 1865) area, Loire-Atlantique department, NW France. Plate 1, figs 4-7 Discussion – Colina petitiana (Millet, 1865) is character- 1854 Cerithium Jucundum Millet, p. 163 (nomen nu- ised by having sculpture consisting of narrow close-set dum). ribs and five or six spiral cords on each whorl, the 3-4 *1865 Cerithium jucundum Millet, p. 594. adapical cords weaker, often alternate in strength, the 1964 Colina jucunda Millet, 1854 [sic] – Brébion, p. abapical two cords more strongly developed and having 236, pl. 6, figs 13-14. prominent tubercles at the sculptural intersections. Millet (1865, p. 595) recorded this species from As- Material and dimensions – Maximum height 13.2 mm (in- semblage I (Reneauleau, Sceaux-d’Anjou, Thorigné, St- complete). NHMW 2015/0133/0277-0279 (2 fragments); Michel).