Nomenclatural comments on and corrections of nomina of some non-marine fossil gastropods

Nomenclatural issues pertaining to selected non-marine gastropods of Cretaceous and Tertiary age are discussed and resolved as follows. [1] Viviparus hammeri (Defrance, 1825) is reinstated; Helicites viviparoides Schlotheim, 1820 is a nomen nudum, made available as Paludina viviparoides Bronn, 1848, a new objective synonym. [2] Viviparus frauenfeldi Le Renard, 1994 is a new objective synonym of Viviparus oulchyensis Wenz, 1919. [3] Lorus is proposed as a nomen novum for Liris Conrad, 1871 [nec Fabricius, 1804]. [3] Wesselinghia is proposed as a nomen novum for Longosoma Wesselingh & Kadolsky, 2006 [nec Hartman, 1944]. [4] Hydrobia incerta (Deshayes, 1862) is reinstated; Hydrobia antoni Le Renard, 1994 is a new objective synonym of this nomen. [5] The species Paludina frauenfeldi Hoernes, 1856 is designated as type species of Sarmata B. Dybowski & Grochmalicki, 1920. [6] The misidentified type species of Annulifer Cossmann, 1921, so far known as ‘Paludina protracta sensu Cossmann 1921, non Eichwald, 1850’, is fixed under Article 70.3 of the Code as understood by Cossmann (1921), and renamed Annulifer annulifer new species. [7] Pomatias turgidulus (Sandberger, 1872) is reinstated; P. turonicus Wenz, 1923 and Cyclostoma squamosum Peyrot, 1932 are its new objective synonyms. [8] Valvata inflata Sandberger, 1875 is reinstated; V. gaudryana Wenz, 1928 [nec Mortillet, 1863] is its new objective synonym. [8] Catinella? montana Pierce, new species, originally published as “[Succineidae] montana Pierce, 1992”, is made available by associating the species epithet with a generic nomen. [9] Proalbinaria subantiqua (d’Orbigny, 1850) is reinstated; its senior synonym Pupa antiqua Matheron, 1832 is a primary junior homonym of Pupa muscorum antiqua Eichwald, 1830. [10] The type species of Palaeostoa Andreae, 1884 is Pupa fontenayi Sandberger, 1871 by subsequent designation by Cossmann (1905), which has precedence over the designation of Clausilia crenata Sandberger, 1871 by Wenz (1923). [11] Palaeostoa elongata (Melleville, 1843), whose original combination was Pupa elongata, is a primary junior homonym of Pupa elongata Bouillet, 1836, an unused name for an unidentified nominal species; pending more information on the taxon at stake, maintenance of the existing usage is recommended. [12] Scalaxis columnella (Deshayes, 1863) is reinstated, with Scalaxis sinister Wenz, 1923 as its new synonym. [13] Eurystrophe olla (Serres, 1844) is reinstated, with Helix janthinoides Noulet, 1868 [nec Helix janthinoides Serres, 1829, a nomen nudum] as its new synonym.

Fossil gastropods Campanile lachesis Bayan, 1870 from the upper Eocene of the Eastern Rhodopes (Bulgaria)

The subject of this study is the description of eight specimens of fossil gastropods Campanile lachesis Bayan, 1870, family Campanilidae, from the fund of the Regional Museum of History in Kardzhali. They were found in the area of the village of Gorna Krepost, Kardzhali Municipality, at the eastern foot of the Archeological Complex Perperikon, in the upper Eocene (Priabonian) limestone layers of the so-called Beli Plast Rhyodacite Complex. The paleoecological traits of the present fauna give ground to infer that this was a very shallow reefal environment with a rocky substrate sandy bottom, overgrown with algae, and the water was warm, with normal salinity.

Modeling durophagous predation and mortality rates from the fossil record of gastropods

Gastropods often show signs of unsuccessful attacks by durophagous predators in the form of healed scars in their shells. As such, fossil gastropods can be taken as providing a record of predation through geological time. However, interpreting the number of such scars has proved to be problematic—Would a low number of scars mean a low rate of attack or a high rate of success, for example? Here we develop a model of population dynamics among individuals exposed to predation, including both lethal and nonlethal attacks. Using this model, we calculate the equilibrium distributions of ages and healed scars in the population and among fossilized specimens, based on the assumption that predation is independent of age or scar number. Based on these results, we formally show that the rates of attack and success cannot be disambiguated without further information about population structure. Nevertheless, by making the assumptions that the non-durophagous predatory death rate is both constant and low, we show that it is possible to use relatively small assemblages of gastropods to produce accurate estimates of both attack and success rates, if the overall death rate can be estimated. We consider likely violations of the assumptions in our model and what sort of information would be required to solve this problem in these more general cases. However, it is not easy to extract the relevant information from the fossil record: a variety of important biases are likely to intervene to obscure the data that gastropod assemblages may yield. Nonetheless, the model provides a theoretical framework for interpreting summary data, including for comparison between different assemblages.

Modelling predation and mortality rates from the fossil record of gastropods

Gastropods often show signs of unsuccessful attacks by predators in the form of healed scars in their shells. As such, fossil gastropods can be taken as providing a record of predation through ge-ological time. However, interpreting the number of such scars has proved to be problematic - would a low number of scars mean a low rate of attack, or a high rate of success, for example? Here we develop a model of scar formation, and formally show that in general these two variables cannot be disambiguated without further information about population structure. Nevertheless, by making the probably reasonable assumptions that the non-predatory death rate is both constant and low, we show that it is possible to use relatively small assemblages of gastropods to produce accurate estimates of both attack and success rates, if the overall death rate can be estimated. We show in addition what sort of information would be required to solve this problem in more general cases. However, it is unlikely that it will be possible to extract the relevant information easily from the fossil record: a variety of important collection and taphonomic biases are likely to intervene to obscure the data that gastropod assemblages may yield.

New fossil gastropod species (Mollusca: Gastropoda) from the upper Miocene of the Canary Islands (Spain)

Ten new species of fossil gastropods from the upper Miocene (Tortonian) of the Canary Islands (Spain) are described. Among these are three species of the genus Patella, a group with few fossil representatives, as well as three others representing the family Trochidae. The remaining new species represent Caenogastropoda. This study improves our knowledge of the fossil malacofauna from the Miocene of these islands. Together with the Azores and Madeira archipelagos, the Canaries belong to the Macaronesian biogeographic region. The described species are indicative of rocky coastal environments, and are thus expanding the current understanding of such ecosystems and their associated marine molluscs such as the family Patellidae whose fossil record is scarce. New species: Patella tintina Martín-González & Vera-Peláez sp. nov., Patella maxoratensis Martín-González & Vera-Peláez sp. nov., Patella mahamensis Martín-González sp. nov., Jujubinus ajachaensis Martín-González & Vera-Peláez sp. nov., Osilinus burgadoi Martín-González sp. nov., Gibbula tindayaensis Martín-González & Vera-Peláez sp. nov., Cerithium miocanariensis Martín-González & Vera-Peláez sp. nov., Tectarius isletaensis Vera-Peláez sp. nov., Morula mionigra Martín-González sp. nov. and Conus fuerteventurensis Vera-Peláez & Martín-González sp. nov.