|Late Quaternary to Recent holoplanktonic Mollusca (Gastropoda) from bottom samples of the eastern Mediterranean Sea: systematics, morphology|
Janssen, A.W. (2012). Late Quaternary to Recent holoplanktonic Mollusca (Gastropoda) from bottom samples of the eastern Mediterranean Sea: systematics, morphology. Boll. Malacologico 48(Suppl. 9): 1-105
In: Bollettino Malacologico. Unione Malacologica Italiana: Milano. ISSN 0394-7149, more
Holoplanktonic Mollusca; Late Quaternary
Holoplanktonic molluscs of 62 bottom samples and the sieving residues < 0.6 mm of a single gravity core, were evaluated. The total number of species found in all samples together is 49 (Pterotracheoidea 11, Janthinidae 2, Limacinoidea 5, Cavolinioidea 16, Cymbulioidea 8, Gymnosomata 5, incertae sedis 2). Results obtained from the residues of bottom samples only give information about which species have been present in the roughly estimated interval ‘late Pleistocene to Holocene, Recent included’. The gravity core samples were previously dated on the basis of planktonic Foraminifera, comprising the interval of latest Saalian (Marine Isotope Stage 6) to Holocene, and some more detailed information on the vertical distribution of the species could be obtained. Construction of a ‘palaeoclimatological curve’, as done by numerous earlier authors, was not attempted. In the systematic part a neotype is designated for Atlanta keraudrenii Lesueur, 1817, and a lectotype for Steira lamanoni Eschscholtz, 1825, making both taxa to junior synonyms of Atlanta peroniiLesueur, 1817. Clio pyramidata f. tyrrhenica nov. f. is introduced. For many species morphological details and questions concerning systematics and/or nomenclature are discussed, in various cases also related to the desired position of a taxon at species, subspecies, or infraspecific level.