Synopsis of valid species-group taxa for freshwater Gastropoda recorded from the European Neogene

Abstract Here we present a complete list of all valid species-group taxa of freshwater gastropods reported from Miocene and Pliocene deposits in Europe. The last comparable work dates back to the 1920s and covered about 1,600 names. The extensive literature research underlying the present work revealed considerable changes in the taxonomic and systematic frameworks of Neogene freshwater gastropods and yielded a total number of 2,156 accepted taxa. Each taxon is accompanied by a full citation of its first description; where the information is available, page number and illustration reference are provided. First descriptions available as open-access full-text sources on the web were linked via hyperlink to the first page of the publication.

This data paper presents a list of all accepted species-group names of the European Neogene freshwater gastropods, each with the current generic combination and reference to the first description. In many cases we referred to the latest available combination, but did not aim for a critical evaluation of these; this contribution is not meant as taxonomic revision.

Methods
The presented data derive from 459 literature sources. Nearly all of the first descriptions have been seen and verified by the authors (97.4%). We checked for correct spelling and nomenclatural validity (to exclude nomina nuda). Where feasible, we tried to include the full citation with indication of page number and illustrations (if present). Despite much effort it was not possible to acquire all of the mentioned publications. In such cases reference and indication of pages/illustrations were taken from Wenz (1923Wenz ( -1930 or other reliable sources where possible. For 9 taxa (0.4%) precise data is missing; for 11 taxa (0.5%) information is incomplete because the respective publication was only partially accessible to the authors (Gozhik and Prysjazhnjuk 1978). An absent indication of illustration does not necessarily imply that there is no depiction in the original publication. Additionally hyperlinks to open-access online sources (e.g., Biodiversity Heritage Library, Internet Archive, Digital Library of the State Museum of Upper Austria, Gallica -Bibliothèque nationale de France, Google Books) are included for many of the publications.

Data setup
The list contains 2,156 accepted species-group taxa recorded for the Miocene and Pliocene. Since stratigraphical boundaries changed in the past decades and the age attributions of many gastropod-bearing localities have been revised since then, many taxa originally recorded for "Miocene" or "Pliocene" localities have been shown to belong to earlier or younger strata and vice versa. Although we tried to find out the most recent and accurate age attributions for the localities containing the relevant taxa, there are still doubtful cases where species may prove not to derive from Neogene sediments. Erroneous records of extant species in Neogene deposits were not considered herein.
It was not possible to trace the correct authorship for the species Melanopsis atanasiui, Caspia dacica, and Prososthenia pertica. The publications mentioned in the species list (Pană 1989;Pană et al. 1981) probably display the first descriptions, but erroneously cite wrong authorships (maybe referring to unpublished manuscripts). None of both works contain any reference to a publication matching the given authority, nor do they list compatible records in synonymy lists. For these three cases the probably correct authorships are stated; those given by the respective authors are included in square brackets.
The dataset includes the following fields: Taxon: Fully spelt species-group name in the current combination, variably with indication of subgenus if stated that way in the literature Genus: Genus name; again, sometimes with indication of subgenus Species/subspecies: Epithet of species and subspecies, if available; given in its currently accepted combination and rank Authority: Authorship and year of the taxon; in parentheses when not in original combination Source: Full reference to the first description of the taxon Page/Illustration: Indication of page number and illustration, if available Seen: To indicate if the authors have personally checked the publication (v -seen, p -information partially available, n -not seen) Source hyperlink: Hyperlink to first page of reference, if available Although much time was spent to acquire all the relevant literature, this list may be incomplete. Moreover, not every described species is incorporated here, since the list only includes accepted names. Unaccepted names, such as primary homonyms, junior synonyms, nomina nuda, nomina dubia, or nomina inquirenda are not covered. For those older than 1923 see Wenz (1923Wenz ( -1930. Readers are invited to contact the authors for cases, where names -especially those thought to refer to accepted species-group taxa -are neither found in the here presented species list nor in Wenz or other sources. Where a species contained one or several subspecific taxa (or they are currently ranked as such), the nominal subspecies was excluded from the list, so as not to overstate the actual number of accepted names.
hausen Institute of Zoology of the Ukrainian National Academy, Kiev), Daniela Esu (University of Rome), Gerhard Haszprunar (The Bavarian State Collection of Zoology, Munich, and Ludwig Maximilians University Munich), Sonja Herzog-Gutsch (Natural History Museum Vienna), Rodica Macaleț (National Institute of Hydrology and Water Management, București), Imre Magyar (Hungarian Natural History Museum, Budapest), Valentin A. Prysjazhnjuk (Ukrainian Academy of Sciences, Kiev), Davit Vasilyan (Universität Tübingen). Daniela Esu (University of Rome) is thanked for her constructive review. This work contributes to the project "Freshwater systems in the Neogene and Quaternary of Europe: Gastropod biodiversity, provinciality, and faunal gradients" financed by the Austrian Science Fund (FWF project no. P25365-B25).