Palaeontographica, Abt. A: Palaeozoology – Stratigraphy Article Vol. 302, Issues 1–6: 1–71 Stuttgart, May 2014 The rlea y MiDDle Miocene mollusc fauna of Lake Rein (Eastern Alps, Austria) by Mathias Harzhauser, Thomas A. Neubauer, Martin Gross & Herbert Binder with 12 plates, 1 text-figure anD 1 table Abstract We present the first thorough revision of the continental mollusc fauna from the early MiDDle Miocene wetlands of the Rein Basin (Styria, Austria). Lake Rein was a shallow ephemeral lake with carbonate sedimentation. Its mollusc assemblage comprises 13 species anD is dominateD by planorbiD gastropods in species anD individual numbers, accompanieD by lymnaeids anD rare hydrobiids. The terrestrial assemblage consists of 35 species with Discidae, Elonidae anD Helicidae as most abundant taxa along with carychiids. The terrestrial gastropods suggest moist woodlanD anD only limiteD areas of open habitats; the freshwater species point to stagnant anD shallow water bodies with dense vegetation anD only very limiteD fluvial input. Many taxa are illustrateD for the first time anD historical mis-identifications are corrected. About one thirD of the species is known so far from the Rein Basin only, but the majority of the species is also known from other MiDDle Miocene lakes anD wetlands of Central Europe. The strongest faunistic relations are indicateD with the Badenian wetlands of the Paratethys Sea anD the so-calleD Silvana-beds of Southern Germany. Hauffenia mandici Neubauer & Harzhauser n. sp., Radix enzenbachensis Neubauer & Harzhauser n. sp., Gyraulus krohi Neubauer & Harzhauser n. sp., Truncatellina pantherae Harzhauser & Neubauer n. sp., Euconulus styriacus Harzhauser, Neubauer & Binder n. sp., “Discus” schneideri Harzhauser & Neubauer n. sp. anD Musculium miocaenicum Neubauer & Harzhauser n. sp. are introduced as new species. Cochlodina (Miophaedusa) reinensiS Harzhauser & Neubauer n. nom. is introduced as replacement name for Clausilia gobanzi Penecke, 1891 non Pfeiffer, 1868. Key words: Freshwater, Te rrestrial, Gastropoda, Bivalvia, Miocene, Alpine lakes. Zusammenfassung Wir präsentieren die erste Revision der kontinentalen Molluskenfauna der frühen mittelmiozänen Feuchtgebiete des Reiner Beckens (Steiermark, Österreich). Der Reiner See war ein seichter ephemerer See mit Karbonatsedimentation. Seine Mollusken- Vergesellschaftung umfasst 13 Arten unD war in Arten- unD Individuenzahlen durch planorbide Gastropoden dominiert, gefolgt von Lymnaeidae unD seltenen Hydrobiidae. Die terrestrische Fauna besteht aus 35 Arten unter denen Discidae, Elonidae unD Helicidae neben selteneren Carychien vorherrschen. Die Landschnecken deuten auf feuchte Wälder unD nur wenige offene Habitate. Die Süßwasserarten zeigen stehende Gewässer mit dichter Vegetation unD nur äußerst geringen fluviatilen Eintrag an. Viele der Arten werden erstmals abgebildet unD historische Falschbestimmungen berichtigt. Rund ein Drittel der Ta xa ist bisher nur aus dem Reiner Becken bekannt, währenD die Mehrheit der Arten auch aus anderen mittelmiozänen Seen unD Feuchtgebieten Zentraleuropas nachgewiesen sind. Die stärksten faunistischen Beziehungen bestehen zu den Wetlands der Paratethys im Badenium unD zu den sogenannten Silvana-Schichten Süddeutschlands. Addresses of the authors: Mathias Harzhauser, Thomas A. Neubauer (corresponding author)& Herbert Binder, Natural History Museum Vienna, Geological- Palaeontological Department, Burgring 7, 1010 Vienna, Austria; e-mail: [email protected]; phone: +43-1-52177- 576, fax: +43-1-52177-459 Martin Gross, Universalmuseum Joanneum Geologie & Paläontologie, Weinzöttlstraße 16, 8045 Graz, Austria. © 2014 E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, Germany www.schweizerbart.de 0375-0442/14/0302-0041 $32.40 2 Mathias Harzhauser et al. Hauffenia mandici Neubauer & Harzhauser n. sp., Radix enzenbachensis Neubauer & Harzhausern. sp., Gyraulus krohi Neubauer & Harzhauser n. sp., Truncatellina pantherae Harzhauser & Neubauer n. sp., Euconulus styriacus Harzhauser, Neubauer & Binder n. sp., “Discus” schneideri Harzhauser & Neubauer n. sp. unD Musculium miocaenicum Neubauer & Harzhauser n. sp. werden als neue Arten beschrieben. Cochlodina (Miophaedusa) reinensiS Harzhauser & Neubauer n. nom. wirD als neuer Name für Clausilia gobanzi Penecke, 1891 non Pfeiffer, 1868 eingeführt. Schlüsselwörter: Süßwasser, Te rrestrisch, Gastropoda, Bivalvia, Miozän, Alpine Seen. Contents Abstract ............................................... 1 4. Plaeoecology ....................................... 5 Zusammenfassung ..................................... 1 5. Systematic Palaeontology ............................ 6 1. Introduction ........................................ 2 Acknowledgements .................................... 38 2. Geological Setting .................................. 3 References ............................................ 38 3. Composition anD Biogeography ...................... 5 Explanation of plates ................................... 48 1. Introduction The knowledge on Miocene continental mollusc fau- inventory was repeatedly anD uncritically listed anD nas of the circum-Mediterranean area is still poor discussed in later papers concerneD with regional geo- compared to the much better describeD marine assem- logy (Hilber 1893, Benesch 1913, Flügel 1975, blages. Moreover, data on Miocene freshwater mol- Ebner & Gräf 1979, Hiden & Rottenmanner luscs are biased towards lake systems with spectacular 2007). Single taxa were reviseD or renameD by Frau- endemic radiations such as the Dinaride Lake System, enfeld (1864), Andreae (1892) anD Schlosser Lake Pannon, Lake Steinheim anD several others (see (1907). Wenz (1923, 1926) was the first to list all the Harzhauser & Mandic 2008 for a review). Lakes describeD taxa critically in his Fossilium Catalogus. with a “normal” fauna, being comparable to modern More recently, Nordsieck (1981), Binder (2002) Central European lake assemblages in generic compo- anD Schnabel (2006) discussed selected taxa of the sition anD species numbers, have been somewhat ne- Rein Basin assemblage. Despite this considerable glecteD so far. One of these lakes formed during the number of systematic papers, in which several new early MiDDle Miocene (Early Langhian, Badenian) in species were established, only for a single taxon a type the Rein Basin along the south-eastern margin of the specimen was designateD anD deposited in a public Eastern Alps at the junction to the Styrian Basin. At collection (Triptychia kleini reinensiS Schnabel that time, this less than 4km long anD c. 2km broaD 2006). All other types are lost or were in fact never basin was covereD by wetlands anD a shallow ephem- designateD as such. Moreover, no illustrations have eral lake that is termed Lake Rein herein. been available so far for many other species anD several Notes on the fossil content of the Rein Beds date erroneous identifications by Gobanz (1854) anD back to the miDDle of the 19th century. Whereas plant Penecke (1891) were uncritically adopted by later remains (Unger 1843, 1850, 1852, 1858, Kubart authors. A problematic issue was the comparison of 1924), ostracods (Gobanz1854, Flügel 1975) anD MiDDle Miocene Lake Rein taxa with those from the vertebrates (Hilber 1915, Mottl 1958, 1970, Early Miocene Lakes of Tuchořice in Czech Republic Hiden & Rottenmanner 2007) are rarely men- anD the Mainz Basin by Gobanz (1854) anD Stand- tioned, the rich gastropod fauna attracted special at- fest (1882), whilst coeval faunas were not particular- tention (e.g., Peters 1853, Gobanz 1854, Stand- ly well known to Gobanz (1854) at that time. This fest 1882, Penecke 1891, Benesch 1913, Hiden resulted in a vague biogeographic anD biostratigraphic & Rottenmanner 2007). The first serious descrip- position of the Lake Rein fauna. The lack of illustrati- tion of the mollusc fauna of the Rein Basin dates back ons supporteD the perpetuation of erroneous identi- to Gobanz (1854). Standfest (1882) extendeD fications. Herein, we illustrate all available taxa anD try this list baseD on new outcrops anD Penecke (1891) to clarify the faunistic relation with other Miocene performed a first revision of the fauna. The taxonomic lake faunas. The rlea y MiDDle Miocene mollusc fauna of Lake Rein 3 2. Geological Setting interfinger with freshwater carbonates, silicifieD lime- stones, limestone breccias, as well as with reDDish car- (byMartin Gross) bonate breccias anD reD residual soils (Hauser 1951, Winkler-Hermaden 1957, Ebner & Gräf 1979, The Rein Basin (Styria, SE Austria; Te xt-Fig.1A–C) Postlet al. 2008). Breccias anD residual soils are sub- belongs to a series of small intramontane basins and/ sumeD as Eggenberg Formation (Hoernes 1880, or embayments along the northern margin of the Clar 1935, Flügel 1997, Flügel et al. 2011). The Neogene Styrian Basin (Kollmann 1965, Kröll et Eckwirt Member encompasses pelitic sands anD grav- al. 1987, Ebner & Sachsenhofer 1991, Gross et els, which characteristically carry heavily altereD crys- al. 2007; Te xt-Fig.1C). Palaeozoic rocks of Devonian talline pebbles (Flügel 1959). Bentonitic intercala- to Carboniferous age (“Graz Palaeozoic”) encircle the tions were found in different stratigraphic levels with- more than 180 m deep basin (Petraschek 1924). in the Rein Beds (Ebner & Gräf 1979, Ebner 1981, Considerable parts of the Neogene filling are covereD Ebner & Gräf 1982). by Quaternary deposits (e.g., Pleistocene terraces, soil While the Rein Beds are interpreteD as limnic de- developments, alluvium;