Fish-life in the Late Miocene Lake Pannon of the Vienna Basin – a review

Fish-life in the Late Miocene Lake Pannon of the Vienna Basin – a review Werner Schwarzhans1,2 1 Zoological Museum, Natural History Museum of Denmark, Universitetsparken 15, 2100 København, Denmark 2 Ahrensburger Weg 103, 22359 Hamburg, Germany https://zoobank.org/D150E6F5-1AFA-48AD-9CFA-19A80976825C Corresponding author: Werner Schwarzhans ([email protected]) Academic editor: Anna Weinmann ♦ Received 21 August 2024 ♦ Accepted 30 September 2024 ♦ Published 10 November 2025 Abstract The long-lived brackish Late Miocene (Pannonian) Lake Pannon formed a large endorheic lake in Europe known for its explosive endemic speciation in mollusks. Unlike the many decades of intense research of fossil mollusks in Lake Pannon, relatively little research has been conducted into its fish fauna including otoliths. Here, I review the Pannonian otoliths from the westernmost outlier of Lake Pannon, the Vienna Basin in Austria, and some smaller samples from the Danubian and Pannonian basins in Hungary. In contrast to the richness and rapid adaptive evolution of mollusk taxa during the Pannonian, the otolith-based fish fauna is relatively lean in species, with 29 species including four new species and four in open nomenclature. Otoliths were found in brackish lake and fluviatile sediments, and freshwater lake deposits away from Lake Pannon. Sixteen species represent genuine lacustrine fishes, with the remainder stemming from freshwater environments or having been transported from freshwater environments into Lake Pannon. Half of the lake fish species are endemic to Lake Pannon. This compares to 36 otolith-based species identified in timeequivalent deposits in the restricted marine Eastern Paratethys, which were almost 100% endemic. The other 50% of the Lake Pannon fishes have roots in the restricted marine Middle Miocene Central Paratethys that preceded the Lake Pannon phase. Unlike mollusks, therefore, the fish fauna of Lake Pannon is characterized furthermore by a relative stasis in evolution with relatively longranging species. The paleoenvironmental affinities of the fishes identified from otoliths is also discussed. The new taxa described are Pannonigadus gen. nov. (Gadidae), Gadiculus weinfurteri sp. nov. (Gadidae), Eleotris pannonicus sp. nov. (Eleotridae), Ponticola planodorsalis sp. nov., and Toxopyge bradicae sp. nov. (both Gobiidae). Key Words Austria, fishes, Lake Pannon, Late Miocene, otoliths, Pannonian Introduction Lake Pannon formed a large inland sea body over the terrain of the preceding Central Paratethys during the Late Miocene, the Pannonian regional stage (e.g., Magyar et al. 1999). This inland sea was characterized by a rapid endemic evolution of the biota trapped therein and is particularly well known for endemic mollusks (e.g., Papp 1951; Papp and Thenius 1954; Harzhauser et al. 2002, 2004; and literature cited in these articles). Fish remains have been less intensively studied and are mainly represented by isolated otoliths, bones, teeth, and rare articulated skeletons. Pannonian otoliths have occasionally been described, mainly from the Vienna Basin, the westernmost outlier of Lake Pannon, by Schubert (1902, 1906), Weinfurter (1950, 1954), and Brzobohatý (1992), and also from the Pannonian Basin by Lörenthey (1906), Pana (1982), Brzobohatý and Pana (1985) and Bosnakoff and Katona (2012). Otoliths of the Sciaenidae, which form a common group in some localities, have been reviewed by Nolf (1981), Schwarzhans (1993), and Bannikov et al. (2018). However, the entirety of the Pannonian otoliths from the Vienna Basin and adjacent regions has never been comprehensively reviewed and ANHMW 126 2025, 81–109 DOI 10.3897/anhmw.168691 Copyright Werner Schwarzhans. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. anhmw.pensoft.net Werner Schwarzhans: Fish-life in the Late Miocene Lake Pannon (Vienna Basin)82 evaluated. During a visit at the Natural History Museum of Wien (NMHW) and the Paleontological Institute of the University of Wien (IPUW), I was able to retrieve otolith collections from both institutions among those described by Weinfurter (1954) and Brzobohatý (1992) and in addition large hitherto undescribed collections in the heritage of Huimann and Weinfurter. These otoliths are reviewed in this paper and interpreted in the context of the paleoecological development of the former Lake Pannon in the Vienna Basin. A total of 29 otolith-based species are recognized as spanning a wide array of 15 families, ranging from the Clupeidae to the Sciaenidae and including four species new to science. Geology The Vienna Basin formed the westernmost outlier of Lake Pannon, and has been connected eastward with the Danube Basin and, further, the Pannonian Basin, forming a continuous water body. The sedimentary history in Lake Pannon is complex, often beginning above a widespread disconformity at the Sarmatian–Pannonian interface along its margins. For instance, in the locality Wiesen, Austria, the highest section of the Sarmatian s.s. is eroded, and the Pannonian deposition begins with the Pannonian C. Elsewhere, in low areas, a transgressive conglomerate (Pannonian A) has been deposited overlain by Pannonian B. The maximum extension of Lake Pannon was reached during the early middle Pannonian E, the so-called Inzersdorf Tegel (Harzhauser et al. 2004). The Vienna Basin formed an approximately 170 km long embayment extending in a SW–NE direction across eastern Austria, southern Czech Republic, and western Slovakia (Fig. 1). The fluvial system discharged into Lake Pannon in the Vienna Basin along the axis from the northeast to the southwest as well as from the west (Harzhauser et al. 2004). During the maximum extension of Lake Pannon in Pannonian E, the preceding fluvial deltas were drowned and pushed outside of the area of the present-day Vienna Basin. During the later stages of the middle and late Pannonian, the water body retreated from the Vienna Basin while it persisted into Pliocene times in the southeastern part of the Pannonian Basin (Magyar et al. 1999). The initially polyto mesohaline (“Caspi-brackish”) environment transformed into a marginal brackish to freshwater marshland environment during this phase (Harzhauser et al. 2022, 2024). During Pannonian F through H, the Paleo-Danube was discharging into Lake Pannon east of the Leitha Mountains, and the lake shore had moved to the Danube Basin. In the Vienna Basin, sediment tracts were deposited in association with the Paleo-Danube river system (Götzendorf and Stixneusiedl) or small freshwater lakes further to the west (Eichkogel). The Pannonian H (Eichkogel) represents the highest stratigraphic level of the Pannonian found in the Vienna Basin from a time when Lake Pannon had fully retreated from the region, and sediments were deposited in freshwater paleoenvironments. Materials and methods Otoliths were obtained from the following locations and are related to the following stratigraphic positions (Fig. 1): - Wiesen (Eisenstadt–Sopron Sub-basin): A few otoliths were studied from the collection of the heritage of Weinfurter and my own collecting in 1972 from the upper Sarmatian s.s. and a single otolith from the Pannonian C. - Tinnye (Hungary, westernmost Pannonian Basin): Otoliths from the heritage of Weinfurter that were obtained from the ornithopsis Zone, which is related to the Pannonian stage B. This is the only collection studied here from beyond the Vienna and Danube basins. - Vösendorf: A classical locality in the Pannonian E, which marked the largest extent of Lake Pannon. The studied material included that described by Weinfurter (1954). - Inzersdorf: Another classical locality in the Pannonian E with a rich otolith collection from the heritage of Huimann. - Götzendorf and Stixneusiedl: Otoliths from these two localities represent the Pannonian F. Götzendorf is slightly older than Stixneusiedl (Harzhauser et al. 2004). The otoliths reviewed here were originally described by Brzobohatý (1992). The otoliths described by Schubert (1902) from Brunn am Gebirge (Pannonian E) pertain to the Sciaenidae and have already been subject to several reviews (see above) and are therefore not specifically reviewed here again. However, new findings from Vösendorf and Inzersdorf help to clarify the status of certain problematic species established by Schubert based on non-optimal specimens. Moreover, the otoliths described by Weinfurter (1950) from the Pannonian H of Eichkogel were not reviewed since they contain only freshwater fishes such as Umbridae, Esocidae, and Percidae. The otolith terminology used in this paper follows Koken (1884) with amendments by Schwarzhans (1978). The interpretation of the morphological features of cyprinid lapilli otoliths follows the terminology used in Schulz-Mirbach and Reichenbacher (2006). All otoliths were studied with a reflected-light microscope. Photographs were made with a Canon EOS 1000D mounted on the phototube of a Wild M400 photomacroscope. They were taken at regular focus levels for each view, remotely controlled from a computer. The individual photographs of each view were stacked with Helicon Focus software from Helicon Soft (Kharkiv, Ukraine). The continuously focused pictures were digitally processed with Adobe Photoshop to enhance contrast or balance exposition or retouch small inconsistencies such as sand grains, incrustations, or pigment spots, as far as this could be done without altering the otolith morphology. Otoliths are shown from the inner face of Annals of the Natural History Museum Vienna 126 2025, 81–109 anhmw.pensoft.net 83 the right side or are converted in the case of left otoliths. Other views are annotated accordingly. Abbreviations used are OL = otolith length; OH = otolith height; OT = otolith thickness; SuL = sulcus length; OCL = length of ostial colliculum; OCH = height of ostial colliculum; CCL = length of caudal colliculum; CCH = height of caudal colliculum; CL = colliculum length in case of single colliculum; CH = colliculum height in case of single colliculum. In gobioid otoliths, OL2 refers to the otolith length below the postdorsal and above the preventral projections. The studied specimens are from the geological collection of the Natural History Museum of Wien, Austria (NHMW-GEO), the collection of the Paleontological Institute of the University of Wien (IPUW-MFN), and material previously studied and figured in publications in the collections of the Senckenberg Museum in Frankfurt am Main (SMF). Other institutional abbreviations used are WAM (Western Australian Museum, Perth), ZMH (Zoological Museum University of Hamburg), and ZMUC (Zoological Museum University Copenhagen). Systematic part The classification of Actinopterygii follows Near and Thacker (2024) except for maintaining the Cyprinodontiformes in the rank of an order instead of a suborder, and for using Cope, 1887, sensu Goodrich, 1930 as authority for the Actinopterygii instead of Woodward, 1891. Class Actinopterygii Cope, 1887, sensu Goodrich, 1930 Actinopterygii indet. Fig. 2A–E Material examined. A single otolith from the Pannonian E of Inzersdorf, NHMW-GEO-1974-1684-0156. Remarks. The single well-preserved otolith is about 2.3 mm high. It vaguely resembles lapilli otoliths of some kind or even cephalopod statoliths. However, it lacks the wing-like extension typical for cephalopod statoliths on Figure 1. Stratigraphic scheme and location plate after Harzhauser et al. (2004). Shaded areas denote Lake Pannon Basin. Stratigraphic position of otolith-bearing localities after Harzhauser et al. (2004) and literature. Asterisk denotes localities of which otolith data have been obtained from referenced literature. anhmw.pensoft.net Werner Schwarzhans: Fish-life in the Late Miocene Lake Pannon (Vienna Basin)84 the posterior margin (Clarke 1978; Clarke and Maddock 1988; Pindakiewicz et al. 2022). Among lapilli, there are no resembling morphologies depicted in the comparative study of Assis (2005). A broad review of extant otoliths singled out those of the Polypteridae as the ones most closely resembling this specimen. Otoliths of the extant Erpetoichthys calabaricus Smith, 1865 (Fig. 2F–J) share with the fossil specimen the overall shape in all views but also show certain important differences. The fossil specimen is more robust than the extant one, shows a sulcus-like pattern along one of the edges (Fig. 2B) that is missing in extant otoliths, and lacks the depression of the dorsal region of the outer face (compare Fig. 2C and 2H) as well as the delicate feature at the center of the outer face visible in the extant specimens (Fig. 2H, I). It is not certain how significant these differences may be, and the fossil specimen is therefore placed in Actinopterygii indet., bearing in mind that it could possibly represent a polypterid. Polypterids represent the plesiomorphic sister group to all other Actinopterygii and have been placed in the separate subclass Cladistia by Cope (1871). Today, polypterids are restricted to freshwater environments in Africa (Froese and Pauly 2024). In the fossil record, they have been recorded from the Miocene of paleo-lake Chad (Otero et al. 2006) but also from South America (Gayet and Meunier 1991). Occurrence in the Miocene of Europe could therefore have been possible, but for a more definitive identification of a fossil European Polypteridae, additional confirmative data would be required such as its characteristic fin spinelets. At Inzersdorf, freshwater fish remains could have been swept in by nearby river discharge or amphihaline predator activity. Other exotic tropical fishes occurring in the European freshwater system are, for example, the Channidae (Brzobohatý 1969; Reichenbacher 1988, 1993; Böhme 2004). Subclass Actinopteri Cope, 1871 Infraclass Neopterygii Regan, 1923 Division Teleostei Müller, 1846 Order Clupeiformes Bleeker, 1859 Family Clupeidae Rafinesque, 1810 Genus Sardina Antipa, 1904 Sardina trolli (Weinfurter, 1954) Fig. 2Q–X 1954 Clupea trolli – Weinfurter: pl. 6, figs 45–46. 2013 “genus Clupeidarum” trolli (Weinfurter, 1954) – Schultz: pl. 73, fig. 1. Material examined. 31 specimens, Pannonian E: 3 specimens, Vösendorf, coll. Weinfurter including holotype (Fig. 2Q, R; IPUW-MFN 21013) and 2 paratypes (IPUW-MFN 21014); 28 specimens, Inzersdorf, coll. Huimann, NHMW-GEO-1974-1684-0114 including 3 well-preserved specimens and 25 fragments. Remarks. Extant otoliths of the genera Clupea and Sardina share a flat, more or less straight ventral rim, and they are more elongate than Alosa otoliths (see Nolf 2018, for figures of extant otoliths). Otoliths of Sardina pilchardus (Walbaum, 1792) differ from those of Clupea harengus Linnaeus, 1758 in the dorsally pronounced posterior rim of the otolith (vs. ventrally expanded) and the rounded or blunt rostral tip (vs. tapering). The fossil otoliths share these features with the otoliths of the single extant species S. pilchardus and are therefore placed in the same genus as Sardina trolli, which now represents the only fossil species in the genus. An otolith specimen of S. pilchardus is figured for comparison (Fig. 2Y–Z). Extant species of Clupea and Sardina are marine fishes with some tolerance to slightly brackish water (Froese and Pauly 2024). The fossil S. trolli probably represented an endemic species in Lake Pannon during the Pannonian that was adapted to somewhat reduced salinity. Order Cypriniformes Bleeker, 1859 Family Cyprinidae Rafinesque, 1810 Genus Carassius Jarocki, 1822 Carassius sp. Fig. 2K–M Material examined. 1 specimen, Pannonian E, Inzersdorf, coll. Huimann, NMHW-GEO-1974-1684-0133. Remarks. The interpretation of fossil cyprinid otoliths from Europe has only become possible through the ground-breaking study by Schulz-Mirbach and Reichenbacher (2006). In comparison to their work, I allocate this slightly damaged singular otolith to the genus Carassius based on the compressed shape, the strongly developed anterolateral edge positioned distinctly backward of the more rounded anteromedial edge, and the mineralization area of the anterior margin extending medially beyond the cranial umbo. Cyprinid fishes are primarily stenohaline freshwater fishes, but the extant species of Carassius show some tolerance to slightly increased salinities (Froese and Pauly 2024). Most likely, the rare occurrence of cyprinid otoliths in Inzersdorf is due to their having been swept in by nearby river discharge or amphihaline predator activity. Genus Leuciscus Cuvier, 1816 Leuciscus sp. Fig. 2O, P Material examined. 1 specimen, Pannonian E, Inzersdorf, coll. Huimann, NMHW-GEO-1974-1684-0157. Remarks. A second, well-preserved specimen differs from the one allocated with Carassius in the slightly more slender shape, the anteromedial edge being placed only slightly in front of the anterolateral edge, and the mineralization area of the anterior margin not extending beyond the cranial umbo. In comparison with the extant cyprinid lapilli Annals of the Natural History Museum Vienna 126 2025, 81–109 anhmw.pensoft.net 85 depicted in Schulz-Mirbach and Reichenbacher (2006), it probably represents a species of Leuciscus, which is consistent with Weinfurter (1954) having mentioned bones and pharyngeal teeth pertaining to two different species of Leuciscus from Vösendorf. Similar to Carassius sp. described above, the singular occurrence of a Leuciscus otolith in Inzersdorf is probably due to its having been swept in by nearby river discharge or amphihaline predator activity. Figure 2. A–E. Polypteridae? indet., NHMW-GEO-1974-1684-0156, Inzersdorf, Pannonian E; F–J. Erpetoichthys calabaricus Smith, 1865, coll. Schwarzhans, Recent, aquarium; K–M. Carassius sp., NHMW-GEO-1974-1684-0133, Inzersdorf, Pannonian E; O, P. Leuciscus sp., NHMW-GEO-1974-1684-0157, Inzersdorf, Pannonian E; Q–X. Sardina trolli (Weinfurter, 1954), Pannonian E; Q, R. Holotype (reversed), IPUW-MFN 21013, Vösendorf; U, V. Paratype (reversed), IPUW-MFN 21014, Vösendorf T; W, X. (reversed), NHMW-GEO-1974-1684-0114, Inzersdorf; Y, Z. Sardina pilchardus (Walbaum, 1792), coll. Schwarzhans, Recent, North Sea. anhmw.pensoft.net Werner Schwarzhans: Fish-life in the Late Miocene Lake Pannon (Vienna Basin)86 Order Gadiformes Bleeker, 1859 Family Gadidae Rafinesque, 1810 Genus Gadiculus Guichenot, 1850 Gadiculus weinfurteri sp. nov. https://zoobank.org/E4A7E29B-C084-4BF2-9837-44D239AD6058 Fig. 3K–M ?1982 Raniceps pannonicus – Pana: pl. 5, figs 1–2. Holotype (and unique specimen): IPUW-MFN 21015, Pannonian E, Vösendorf, coll. Weinfurter. Diagnosis. OL:OH = 1.6. Ventral rim shallower than dorsal rim; rims smooth. Inner face flat. Ostial colliculum smaller than caudal colliculum, latter reaching posterior rim of otolith. Collum broad; pseudocolliculum long, distinct. Outer face smooth. Description. Holotype oval in shape, 4 mm in length. Anterior rim broadly rounded, posterior rim rounded, more projecting than anterior rim. Dorsal rim shorter and higher than ventral rim, highest at rounded predorsal angle. All rims smooth, slightly and irregularly undulating. Inner face flat, slightly concave in anterior view and slightly twisted in ventral view. Sulcus slightly inframedian, typical homosulcoid. Colliculi slightly elevated, well-defined; CCL:OCL = 1.8; OCL:OCH = 1.5; CCL:CCH = 2.5. Collum as broad as ostial colliculum long; pseudocolliculum distinct, longer than collum broad. Ostial colliculum terminating distant from anterior rim of otolith; caudal colliculum reaching posterior rim of otolith. No clear ventral furrow; no dorsal depression. Outer face convex, smooth. Etymology. In memory of E. Weinfurter in recognition of his work on fossil otoliths and fish remains from Austria. Remarks. The extant Gadiculus argenteus Guichenot, 1850, is known in the fossil record since the Langhian, possibly even late Burdigalian (Schwarzhans 2010; Nolf 2013) from the North Sea Basin, the Mediterranean, and the Central Paratethys. A second, distinctly more slender fossil species (Gadiculus deurnensis Nolf, 1977) is common in the Late Miocene of the North Sea Basin. Gadiculus weinfurteri resembles G. argenteus in proportions but differs in the shallower ventral rim, the long caudal colliculum reaching the posterior rim of the otolith, and the smooth rims and outer face (vs. crenulated and with numerous radial furrows). Gadiculus weinfurteri probably represents an endemic species that had derived in Lake Pannon from an entrapped population of G. argenteus. Pana (1982) figured a non-type of Raniceps pannonicus Pana, 1982, from the Pannonian C/D of Romania that may represent G. weinfurteri; however, her drawings are schematic and inconclusive. Genus Pannonigadus gen. nov. https://zoobank.org/9DC727AD-89EE-4693-92FD-7A2AFED155EF Type species. Pannonigadus ponticus (Weinfurter, 1954), originally described as Otolithus (Gadidarum) ponticum by Weinfurter. Diagnosis. A fossil otolith-based genus of the family Gadidae that is characterized by the following unique combination of characters. The otoliths are symmetrically oval in shape with the anterior and posterior tips broadly rounded and the dorsal and ventral rims relatively shallow, reaching sizes of about 6 mm in length. The ratio OL:OH ranges from 1.9 to 2.1; the ratio OCL:CCL ranges from 0.85 to 1.1. The inner face is slightly bent along the horizontal axis. The sulcus is distinctly homosulcoid with moderately large, oval-shaped and nearly equally sized colliculi which are separated by a broad collum nearly of the size of the length of the ostial colliculum. The pseudocolliculum is well-developed. The colliculi terminate at some distance from the anterior and posterior rims of the otolith. The ventral furrow is broad and distinct and runs across the center of the ventral field of the inner face at about equal distance from the sulcus and the ventral rim of the otolith. Etymology. A combination of Pannon, from Lake Pannon of the Late Miocene, and the genus name Gadus. Remarks. This unique combination of the otolith characteristics is difficult to relate to any extant or fossil gadid otolith pattern. The broad collum resembles Gadiculus otoliths and also certain species of the fossil genus Palimphemus. However, the colliculi are larger than usually found in Gadiculus, and the bending of the inner face, the outline of the otolith, and the broad ventral furrow and its position also differ from Gadiculus. The symmetrical otolith shape and the nearly equally sized colliculi as well as the expression of the ventral furrow distinguish Pannonigadus from all known species of Palimphemus. There are also otoliths in the family Lotidae that show some superficial similarity, primarily in the shape of the otolith, the position of the ventral furrow, and the curvature of the inner face, i.e., otoliths of the genus Molva (see Nolf, 2018). However, Pannonigadus differs in the small size of the colliculi, the broad collum, and the presence of a distinct pseudocolliculum (vs. absent). Pannonigadus appears to represent an endemic gadid genus in the Central Paratethys that may have been adapted to restricted marine and moderately brackish environments. Its origin remains elusive in time and space. The first record is from the late Sarmatian (see below). There do not appear to be any skeletal finds from the Sarmatian that could possibly relate to Pannonigadus. Its latest occurrence is recorded from the Pannonian G equivalent of Hungary by Bosnakoff and Katona (2012). Jovanović et al. (2010) figured a poorly preserved gadid otolith from the latest Pannonian of Serbia that may represent a Pannonigadus specimen. Fragmented articulated skeletons from the Pannonian E have been allocated with gadiform fishes (Schultz 2013 and literature cited therein): Lota hulai Pietschmann, 1934 and Phycis suessi Steindachner, 1860. The systematic placement of these skeletal remains remain doubtful and require a review. It is not known in as how much they may relate to Pannonigadus. Annals of the Natural History Museum Vienna 126 2025, 81–109 anhmw.pensoft.net 87 Species. Pannonigadus ponticus (Weinfurter, 1954) in the middle and upper Pannonian (sensu Harzhauser et al. 2004), and possible additional finds that cannot be attributed to a defined species from the late Sarmatian s.s. and the upper Pannonian. Pannonigadus ponticus (Weinfurter, 1954) Fig. 3A–I 1954 Otolithus (Gadidarum) ponticum – Weinfurter: figs 47–48. 1982 Raniceps pannonicus – Pana: pl. 2, figs 1–2, pl. 5, figs 3–4 (non figs 1–2), pl. 6, figs 3–5. ?1982 Merluccius vulgaris Fleming, 1828 – Pana: pl. 6, figs 6–7. 1985 Raniceps pannonicus? Pana, 1982 – Brzobohatý and Pana: pl. 57, figs 1–2. ?2010 “Genus Gadidarum” ponticum (Weinfurter, 1954) – Jovanović et al.: pl. 2, fig. 5. 2012 Gadidae indet. – Bosnakoff and Katona: pl. 1, fig. 10, ?9. 2013 Teleostei indet. – Schultz: pl. 96, fig. 5 (holotype of Ot. (Gadidarum ponticum). Material examined. 41 specimens, Pannonian E: 18 specimens, Vösendorf, coll. Weinfurter including holotype (Fig. 3E–F; IPUW-MFN 21016) and 17 topoand paratypes (IPUW-MFN 21017); 23 specimens, Inzersdorf, coll. Huimann, NHMW-GEO-1974-1684-0115–0116. Remarks. Weinfurter’s holotype is not well preserved, and his drawings in 1954 were not sufficiently conclusive. Thus, Nolf (2013) noted that the species could not be evaluated based on Weinfurter’s iconography. Several well-preserved specimens now available from the collection of Figure 3. A–I. Pannonigadus gen. nov. ponticus (Weinfurter, 1954), Pannonian E; E, F. holotype (reversed), IPUW-MFN 21016, Vösendorf; I. paratype (reversed), IPUW-MFN 21017, Vösendorf; A–D, G–H. NHMW-GEO-1974-1684-0115–0116, Inzersdorf; J. Pannonigadus sp., IPUW-MFN 21018, late Sarmatian s.s., Wiesen; K–M. Gadiculus weinfurteri sp. nov., holotype, IPUW-MFN 21015, Pannonian E, Vösendorf. anhmw.pensoft.net Werner Schwarzhans: Fish-life in the Late Miocene Lake Pannon (Vienna Basin)88 Huimann from Inzersdorf help to better define the species as presented in the generic diagnosis above. Other fossil references remain problematic, particularly the one by Jovanović et al. (2010), and may be better recorded as Pannonigadus? sp. At least one of the specimens figured by Bosnakoff and Katona (2012) as Gadidae indet. from the Pannonian G equivalent of Hungary also represents Pannonigadus ponticus. Raniceps pannonicus Pana, 1982, from the Pannonian B–C of Romania is a junior synonym of P. ponticus. Thus, the range of Pannonigadus ponticus stretches at least across Pannonian B to G. Pannonigadus sp. Fig. 3J Material examined. 1 incomplete otolith from the late Sarmatian s.s. of Wiesen, coll. Weinfurter, IPUW-MFN 21018. Remarks. The single incomplete and rather poorly preserved otolith from the Sarmatian of Wiesen seems to represent the earliest record of Pannonigadus. As far as discernable the broad collum, small oval colliculi, presence of a pseudocolliculum, and overall oval otolith shape indicate that the otolith fragment probably represents a specimen of Pannonigadus. It differs slightly from the younger P. ponticus only in the ventral furrow being positioned closely and parallel to the ventral rim of the otolith (vs. running across the center of the ventral field). Order Gobiiformes Bleeker, 1859 Family Eleotridae Bonaparte, 1835 Eleotris Scopoli, 1777 Eleotris pannonicus sp. nov. https://zoobank.org/1B1882AB-0A62-4CEA-832A-83DDD72DA2B5 Fig. 4H–J Holotype (and unique specimen): IPUW-MFN 21019, Pannonian B (ornithopsis zone), Tinnye near Budapest, coll. Weinfurter. Diagnosis. OL:OH = 1.45; OL2:OH = 1.2. Anterior rim vertical; posterior rim with relatively strong postdorsal projection. Sulcus large, wide, deep, with nearly level ostial lobe and no subcaudal iugum. Ventral furrow strong. Description. The unique holotype is well-preserved and 3.45 mm in length. OH:OT = 3.0. Anterior rim nearly vertical, slightly indented at level above ostium. Dorsal rim shallow, slightly ascending to broad postdorsal angle, coarsely undulating. Ventral rim straight, smooth. Posterior rim nearly vertical in lower section and with prominent and pointed postdorsal projection. Inner face mildly bent in horizontal direction. Sulcus large, centrally positioned, deep; OL2:SuL = 1.35. Sulcus inclination angle 13°. Ostial lobe almost flat; ostium ventrally more expanded; no subcaudal iugum. Crista superior distinct; dorsal depression wide but with indistinct margins. Ventral furrow distinct, more regularly curved than ventral rim of otolith; ventral field between ventral furrow and sulcus bulged. Outer face flat, except for slightly outward bent postdorsal projection, smooth. Etymology. Named after Lake Pannon. Remarks. A few butid (Rückert-Ülkümen 1992, 1993; Gierl et al. 2013) and eleotrid (Schwarzhans et al. 2020; Carnevale and Schwarzhans 2022) otoliths have been described from the European Oligocene and Miocene, including one instance of fish skeletons with otoliths in situ (Reichenbacher et al. 2013). Butid otoliths are relatively easy to recognize by their asymmetrically, forward positioned sulcus that nearly opens anteriorly. The recognition of eleotrid otoliths and distinction from the many gobiid taxa is less straightforward. Schwarzhans et al. (2020) commented that their centrally positioned sulcus resembles the status in gobiids and concluded that “Eleotris otoliths are recognized by the combination of a large, wide, and mostly deep sulcus with low or no ostial lobe and no subcaudal iugum.” We described two otolithbased Eleotris species from the Tortonian of Calabria from a marginal marine mangrove environment, and later Carnevale and Schwarzhans (2022) described a further species from the genus Bostrychus from the Messinian Lago Mare phase of central Italy. Chalupova (2008) figured an otolith as Gobius sp. from the Sarmatian s.s. of Slovakia that may represent a species of Bostrychus. Of these, Eleotris pannonicus most resembles E. omuamuaensis Schwarzhans, Agiadi & Carnevale, 2020, from the Tortonian of Calabria but differs in the more strongly developed postdorsal projection, the more steeply inclined sulcus (13° vs. 7–10°), and the flat ventral rim (vs. curved). In the Pannonian, E. pannonicus could potentially be confused with Ponticola dorsorostralis or P. planodorsalis sp. nov. Eleotris pannonicus differs from P. dorsorostralis in the rather low dorsal rim and from both species in the large sulcus, the lack of a preventral projection, and the postdorsal projection being only slightly bent outward (vs. strongly bent outward). Family Gobiidae Cuvier, 1816 Remarks. Gobiid otoliths are a common element in shallow-water environments of the Paratethys and also in Lake Pannon. However, they are under-represented in some studies of Pannonian otoliths—for instance, there was none recorded in Schubert (1906), Jovanović et al. (2010), or Bosnakoff and Katona (2012)—while they were commonly reported in Weinfurter (1954) and Brzobohatý (1992). The lack of gobiid records in certain studies could represent a collecting bias if too large mesh sizes were used. In contrast, Pana (1982) and Brzobohatý and Pana (1985) documented an abundance of goby otoliths from the Pannonian B through D that have been attributed to many different species. However, these Annals of the Natural History Museum Vienna 126 2025, 81–109 anhmw.pensoft.net 89 otoliths are mostly of extremely small sizes of less than 1 mm in length, sometimes even smaller than 0.5 mm. In addition, the otoliths are documented in schematic and non-informative drawings and therefore cannot be identified to species or even generic level. Genus Neogobius Iljin, 1927 Neogobius sculptus (Weinfurter, 1954) Fig. 4A–G 1954 Gobius dorsorostralis sculpta – Weinfurter: pl. 6, figs 51–52. 2010 Gobius dorsorostralis Weinfurter, 1954 – Schwarzhans: pl. 103, figs 2–4. 2013 Gobius dorsorostralis Weinfurter, 1954 – Schultz: pl. 92, fig. 2. 2014 Gobius dorsorostralis Weinfurter, 1954 – Schwarzhans: pl. 8, figs 1–2. ?2014 Gobius aff. dorsorostralis Weinfurter, 1954 – Schwarzhans: pl. 8, fig. 3. Material examined. 12 specimens: 3 specimens, late Sarmatian s.s., Wiesen, coll. Schwarzhans; 9 specimens, Pannonian E: 2 specimens, Vösendorf, coll. Weinfurter including holotype (Fig. 4A–C; IPUW-MFN 21020) and 1 paratype (IPUW-MFN 21021); 7 specimens, Inzersdorf, coll. Huimann, NHMW-GEO-1974-1684-0118. Remarks. Weinfurter considered the two type specimens as representing a subspecies of Gobius dorsorostralis (now placed in Ponticola, see below). A review of the type specimens now revealed that they differ significantly from Ponticola dorsorostralis in being more compressed (OL:OH = 1.05–1.2 vs. 1.25–1.45; OL2:OH = 0.9–1.05 vs. 1.05–1.2), exhibiting intensely crenulated dorsal and posterior rims and outer face with furrows, and possessing indications of a small subcaudal iugum. These traits are typical for otoliths of the genus Neogobius. Otoliths of N. sculptus do not seem to grow to the large sizes of P. dorsorostralis; the maximum otolith length in N. sculptus is 3.2 mm (holotype) and in P. dorsorostralis 5 mm (holotype). In addition, both species show a tendency to become more slender with size, which can make it difficult to distinguish their juvenile forms less than 2 mm in length. Other Neogobius otolith species have been described from the Konkian of Kazakhstan (N. udovichenkovi Bratishko, Schwarzhans and Reichenbacher 2015) and from the time-equivalent Bessarabian of Ukraine (N. bettinae Bratishko, Kovalchuk & Schwarzhans, 2017, and N. rhachis Rückert-Ülkümen, 1993). None of these shows an intense marginal crenulation like N. sculptus, and N. bettinae and N. rhachis are also thicker. Proneogobius pullus (Kramberger, 1882) from the lower Sarmatian s.s. of Croatia was reported with otoliths in situ (Schwarzhans et al. 2017b). This species has a smooth and relatively low dorsal rim and a distinct, albeit small, subcaudal iugum and is interpreted to be phylogenetically positioned near the base of the endemic Ponto-Caspian goby clade. In conclusion, Neogobius sculptus appears to have been an endemic species of the late Sarmatian s.s. of the Central Paratethys and the Pannonian of Lake Pannon. A single specimen tentatively referable to N. sculptus from the Serravallian of SE Turkey (see reference list above) probably represents a juvenile otolith of another species in this genus. Genus Ponticola Iljin, 1927 Ponticola dorsorostralis (Weinfurter, 1954) Fig. 4K–Y 1954 Gobius dorsorostralis – Weinfurter: pl. 6, figs 49–50. 2013 Gobius dorsorostralis Weinfurter, 1954 – Schultz: pl. 92, figs 1, 3. ?2017 Ponticola dorsorostralis (Weinfurter, 1954) – Bratishko, Kovalchuk and Schwarzhans: figs 3.9–3.18. Material examined. 49 specimens: 3 specimens, late Sarmatian s.s., Wiesen, coll. Weinfurter, IPUW-MFN 21022; 46 specimens, Pannonian E: 4 specimens, Vösendorf, coll. Weinfurter including holotype (Fig. 4K, L; IPUW-MFN 21023) and 3 paratypes (IPUW-MFN 21024); 42 specimens, Inzersdorf, coll. Huimann, NHMWGEO-1974-1684-0120, 0121, 0122. Remarks. A review of Weinfurter’s type specimens as well as multiple further specimens from Inzersdorf and the upper Sarmatian of Wiesen revealed that P. dorsorostralis is characterized by a pointed preventral projection and a long postdorsal projection that is strongly curved outward, which is visible in dorsal views (Fig. 4L, N, U, W, Y); only the holotype differs slightly in a less strongly developed postdorsal projection (Fig. 4K, L). The dorsal rim is variably developed and can be domed (Fig. 4K, M, and in smaller specimens like Fig. 4T, V, X) or, in some large specimens, coarsely undulating (Fig. 4P, S). Ponticola dorsorostralis differs from P. zosimovichi Bratishko, Schwarzhans & Reichenbacher, 2015, in the longer and strongly outward bent postdorsal projection and the more strongly curved dorsal rim. No Ponticola otoliths are known from the fully marine upper Bessarabian of the Crimea (Bratishko et al. 2023) or the Medobory backreef facies from the upper Badenian of Ukraine (Schwarzhans et al. 2022, 2024), indicating that the genus Ponticola may already have been adapted to euryhaline and transitional marine environments at the time. Ponticola dorsorostralis is common in the upper Sarmatian s.s. of the Central Paratethys at Wiesen and the Pannonian of Lake Pannon. Time-equivalent records from the marginal marine Bessarabian of Ukraine by Bratishko et al. (2017) are here only tentatively associated with P. dorsorostralis, since they have a less expanded and less outward curved postdorsal projection than the Pannonian specimens. anhmw.pensoft.net Werner Schwarzhans: Fish-life in the Late Miocene Lake Pannon (Vienna Basin)96 Figure 7. A–D. Lates brunnensis (Weinfurter, 1954), holotype (reversed), IPUW-MFN 21032, Pannonian E, Vösendorf; E, F. Lateolabrax japonicus (Cuvier, 1828), ZMH, Recent, off southern China; G, H. Lates mariae (Linnaeus, 1758), ZMH, Recent, Lake Tanganyika; I–U. Eomorone kuehni (Weinfurter, 1954), Pannonian E; I–J. holotype (reversed), IPUW-MFN 21033, Vösendorf; K–N. holotype of E. kuehni gracilis, IPUW-MFN 21034, Vösendorf; O. (reversed), NHMW-GEO-1952-0039-0003, Brunn-Vösendorf; P–U. NHMW-GEO-1974-1684-0125 (P, Q, T, U. Reversed), Inzersdorf; V–Y. Morone serrata Weinfurter, 1954, Pannonian E, Vösendorf, V–W. holotype, IPUW-MFN 21036; X–Y. IPUW-MFN 21037; Z–AA. Morone labrax (Linnaeus, 1758), coll. Schwarzhans, Recent, Egypt; AB–AC. Morone saxatilis (Walbaum, 1792), ZMH-14098, Recent, off New York. Annals of the Natural History Museum Vienna 126 2025, 81–109 anhmw.pensoft.net 97 2 specimens, Brunn-Vösendorf, coll. Wittula, NHMWGEO-1952-0039-0003; 59 specimens, Inzersdorf, coll. Huimann, NHMW-GEO-1974-1684-0123, 0124, 0125, 0155. Remarks. The genus Eomorone with the type species Eomorone kokayi Gaudant, 2005 was established from a number of articulated skeletons with otoliths in situ from the upper Badenian freshwater to brackish water environment of the Várpalota Basin in Hungary. Gaudant (2005) figured several of the otoliths he found in situ in E. kokayi that show quite a range of variability. Otoliths of E. kuehni are similar to those of E. kokayi in many aspects, differing primarily in the well-developed postdorsal angle (vs. rounded or depressed). Given that the occurrence of both species is also similar in space and time and environment, it is clear that they are closely related and should represent a common lineage. The broad variability depicted for the in situ otoliths of E. kokayi also suggests that the mild differences observed in the Lake Pannon specimens that led Weinfurter to describe two subspecies must be regarded as an aspect of variation too. Schultz (2013 and literature cited therein) mentioned incomplete skeletal remains consisting of a partial tail skeleton and bones from the pectoral girdle of an unidentifiable Moronidae from the Pannonian B. Genus Morone Mitchill, 1814 Morone serrata Weinfurter, 1954 Fig. 7V–Y 1954 Morone serrata – Weinfurter: pl. 6, figs 31–32. 2013 Teleostei indet. – Schultz: pl. 96, fig. 3. Material examined. 7 specimens, Pannonian E: 2 specimens, Vösendorf, coll. Weinfurter including the holotype (Fig. 7V–W; IPUW-MFN 21036) and one other specimen (IPUW-MFN 21037); 5 mostly poorly preserved specimens, Inzersdorf, coll. Huimann, NHMW-GEO-1974-1684-0134, 0166. Remarks. Weinfurter (1954) described Morone serrata based on a unique, extremely large otolith with a broken rostrum. The fragment is 15.5 mm in length and when reconstructed for the rostrum would have been about 20 mm, which would correspond to a fish size of 1 m or more (calculated from extant otoliths figured by Lombarte et al. 2006). The incompleteness of the holotype has led Nolf (2013) to consider Morone serrata a doubtful species. However, Weinfurter’s collection from Vösendorf also contains a specimen of 9 mm in length (Fig. 7X–Y), which he apparently did not recognize as belonging to the same species but which is well preserved and is used here to redefine the species. Diagnosis (based on the non-type specimen of Fig. 7X–Y): OL:OH = 2.15; OH:OT = 4.2–4.6. Dorsal rim shallow, crenulated or serrated posteriorly. Otolith strongly bent along horizontal axis. CaL:OsL = 1.65. Caudal curvature 52–57°. Description (based on the non-type specimen of Fig. 7X– Y): Elongate, thin and delicate otoliths that apparently can reach very large sizes (about 20 mm in length). Dorsal rim shallow, highest anteriorly in low predorsal lobe, slightly inclining toward rounded postdorsal angle positioned far backward. Posterior part of dorsal rim slightly crenulated (serrated in large holotype). Ventral rim deepest at its middle, anteriorly and posteriorly less strongly curved, smooth. Rostrum long, with rounded tip, 15 % of OL; antirostrum and excisura minute. Posterior rim rounded or angular. Inner face strongly convex in horizontal direction. Sulcus distinctly supramedian, OL:SuL = 1.25; CaL:OsL = 1.65. Ostium widened, spatulate, horizontal, broadly opening to anterior rim. Cauda narrow, deepened, long, with distinctly bent caudal tip at 52–57°. Dorsal depression indistinct, no ventral furrow, but sometimes irregular depression closely below anterior half of cauda. Outer face distinctly concave, relatively smooth. Remarks. In most modern literature, the extant American species are placed in the genus Morone and the European ones in the genus Dicentrarchus, but I have maintained the same genus name (Morone) for both flocks. Morone serrata is morphologically closer to the American form M. saxatilis (Walbaum, 1792) (Fig. 7AB–AC) than the European M. labrax (Linnaeus, 1758) (Fig. 7Z–AA). It differs from both species (and other extant species of the genus) in the more steeply bent caudal tip (52–57° vs. ≤ 40°) and the specific shape and serration of the dorsal rim. Otoliths of Morone serrata are distinctly more elongate than those of the coeval Eomorone kuehni (OL:OH = 2.15 vs. 1.65–1.8). They differ additionally from E. kuehni in the shape of the dorsal rim and the more strongly bent caudal tip. Family Sciaenidae Cuvier, 1828 Remarks. Sciaenid otoliths are common in the Pannonian. They are also large, and it therefore may be that sampling bias has affected some collections (possibly Götzendorf) and some of the records in past literature such as Schubert (1902) and Lörenthey (1906). Sciaenid otoliths from the Pannonian have been subject to reviews by Nolf (1981), Schwarzhans (1993), and Bannikov et al. (2018). I have therefore refrained here from detailed descriptions and discussions, except where new pertinent data have become available. Synonymy listings are only included for types and for the Pannonian of the Vienna Basin. Genus Chaoia Bannikov, Schwarzhans & Carnevale, 2018 Chaoia angulata (Schubert, 1902) Fig. 8A–J 1902 Otolithus (Sciaena) irregularis var. angulata – Schubert: pl. 10, fig. 8. ?1902 Otolithus (Sciaena) aff. speciosus Koken, 1891 – Schubert: pl. 10, fig. 10. 1954 Sciaena angulata Schubert, 1902 – Weinfurter: pl. 6, figs 33–34. anhmw.pensoft.net Werner Schwarzhans: Fish-life in the Late Miocene Lake Pannon (Vienna Basin)98 1977 Sciaena moguntiniformis – Pana: pl. 2, figs 1–12. 1992 “genus aff. Umbrina” kokeni (Schubert, 1902) – Brzobohatý: pl. 1, fig. 8. 1993 Trewasciaena kokeni (Schubert, 1902) – Schwarzhans: fig. 175 (non figs 171–174). 1995 Sciaena moguntiniformis Pana, 1977 – Pana: pl. 4, figs 1–4. 2012 Umbrina sp. – Bosnakoff and Katona: pl. 1, fig. 5. 2013 Trewasciaena kokeni (Schubert, 1902) – Schultz: pl. 91, fig. 3. 2018 Chaoia moguntiniformis (Pana, 1977) – Bannikov, Schwarzhans and Carnevale: fig. 5A–I. Material examined. 531 specimens: 35 specimens, Pannonian E, Inzersdorf, coll. Huimann, NHMWGEO-1974-1684-0142, 0143, 0144, 0145; 496 specimens Pannonian F: 475 specimens, Götzendorf, NHMWGEO-1990-0025-0003; 21 specimens, Stixneudiedl, NHMW-GEO. Remarks. This species was reviewed by Nolf (1981), and he rejected it based on inadequate preservation; Schwarzhans (1993) regarded it as a synonym of Trewasciaena kokeni (Schubert, 1902); Bannikov et al. (2018) followed Nolf in rejecting this nominal species. As a result, Sciaena moguntiniformis Pana, 1977 was considered valid and was made the type species of the fossil otolith-based genus Chaoia in Bannikov et al. (2018). A specimen from the Pannonian of Vösendorf from the collection of the Stuttgart Museum of Natural History (SMNS 80556-2) was also figured in Bannikov et al. (2018) as C. moguntiniformis. Abundant well-preserved specimens from the Pannonian of Inzersdorf and Götzendorf of different sizes were now available for study and clearly showed that C. angulata is a valid species and takes senior priority over C. moguntiniformis and thus becomes the type species of the genus Chaoia. The specimens figured here are used to redefine the species. Diagnosis. OL:OH 1.55–1.75. Dorsal rim shallow; ventral rim regularly curved. Ostium large, spatulate. Cauda long, its ear portioned bent downward at nearly 90° angle; intercaudal space (distance between rear margin of ostium and downturned portion of cauda) 30–35% of SuL. Dorsal field narrow. Outer face without distinct umbo. Description. Large, robust, elongate otoliths up to at least 12.5 mm in length (Fig. 8D–F). OH:OT = 2.0–2.3. Anterior rim broadly rounded. Dorsal rim shallow, almost straight, slightly undulating, with rounded angle at junction with posterior rim. Posterior rim round, dorsally pronounced. Ventral rim regularly curved, slightly deeper than dorsal rim, smooth. Inner face strongly convex, with large sulcus; OL:- SuL = 1.07–1.12. Ostium wide, shallow, spatulate, about as long as cauda; CaL:OsL = 0.97–1.05. Cauda narrow, steeply curving at its rear, its tip sometimes bent forward and terminating close to postventral rim. Intercaudal space moderately wide, 30–35% of SuL. Dorsal field very narrow. Outer face flat to slightly convex with broad posterior region but without distinct umbo, smooth or plicate. Remarks. The narrow dorsal field and low OL:SuL of 1.07–1.12 (vs. 1.16–1.2) distinguishes C. angulata from the parallel occurring Trewasciaena kokeni. The more elongate shape (OL:OH = 1.55–1.75 vs. 1.3– 1.45) and the relatively wide intercaudal space (30– 35% of SuL vs. ≤ 28°) distinguishes C. angulata from coeval Umbrina species. Chaoia angulata is known throughout the Pannonian in Lake Pannon, the Dacian (Early Pliocene) of the Dacian Basin and possibly the late Badenian (Schubert’s reference to Otolithus (Sciaena) aff. speciosus). Genus Trewasciaena Schwarzhans, 1993 Trewasciaena kokeni (Schubert, 1902) Fig. 8K–T 1902 Otolithus (Sciaenidarum) kokeni – Schubert: pl. 10, fig. 18. 1902 Otolithus (Sciaena?) telleri – Schubert: pl. 10, fig. 16. 1902 Otolithus (Sciaena?) levis – Schubert: pl. 10, fig. 9. 1902 Otolithus (Sciaena?) excisus – Schubert: pl. 10, fig. 17. 1906 Otolithus (Sciaenidarum) loczyi – Lörenthey: pl. 2, fig. 8. 1906 Otolithus (Sciaenidarum) aff. loczyi – Lörenthey: pl. 3, figs 23, 24. 1954 Sciaena telleri Schubert, 1902 – Weinfurter: pl. 6, figs 35–36. 1993 Trewasciaena kokeni (Schubert, 1902) – Schwarzhans: figs 171– 174 (non 175, ?176–177). 2010 Trewasciaena kokeni (Schubert, 1902) – Jovanović et al.: pl. 2, figs 1–2. 2012 “genus aff. Umbrina” kokeni (Schubert, 1902) – Bosnakoff and Katona: pl. 1, figs 11–12. 2013 Trewasciaena kokeni (Schubert, 1902) – Schultz: pl. 91, figs 1–2, 4–5. 2013 Teleostei indet. – Schultz: pl. 96, fig. 4. 2018 Trewasciaena kokeni (Schubert, 1902) – Bannikov, Schwarzhans and Carnevale: fig. 8F–H (see there for further references). 2021 Trewasciaena cf. kokeni (Schubert, 1902) – Přikryl, Brzobohatý and Carnevale: figs 2–7. Material examined. 36 specimens, Pannonian E, Inzersdorf, coll. Huimann, NHMW-GEO-1974-1684-0150, 0151, 0152, 0153. Remarks. Trewasciaena kokeni is a common species in Lake Pannon throughout the Pannonian and is also known from the Messinian Lago Mare phase of Italy (Bannikov et al. 2018). There are two tentative records from the Pontian of the Caspian Basin (Schwarzhans 1993). In addition, a juvenile specimen of T. cf. kokeni has been described with otoliths in situ from the lowermost Pannonian F of the Czech Republic by Přikryl et al. (2021). The figured otolith is consistent with isolated otoliths of T. kokeni of the same size thus confirming the identification. Annals of the Natural History Museum Vienna 126 2025, 81–109 anhmw.pensoft.net 99 Figure 8. A–J. Chaoia angulata (Schubert, 1902); A–C, G–I. (A–C, H–I. Reversed), NHMW-GEO-1974-1684-0145, Inzersdorf, Pannonian E; D–F, J. NHMW-GEO-1990-0025-0003, Götzendorf, Pannonian F; K–T. Trewasciaena kokeni (Schubert, 1902), NHMW-GEO-1974-1684-0152–0153 (K, L, P–R. reversed), Inzersdorf, Pannonian E; U–Z. Umbrina cirrhosoides (Schubert, 1902), NHMW-GEO-1974-1684-0160 (reversed), Inzersdorf, Pannonian E; AA–AF. Umbrina subcirrhosa (Schubert, 1902), NHMW-GEO-1974-1684-0161 (reversed), Inzersdorf, Pannonian E; AG–AH. Umbrina sp., NHMW-GEO-1974-1684-0162 (reversed), Inzersdorf, Pannonian E. anhmw.pensoft.net Werner Schwarzhans: Fish-life in the Late Miocene Lake Pannon (Vienna Basin)100 Genus Umbrina Cuvier, 1816 Umbrina cirrhosoides (Schubert, 1902) Fig. 8U–Z 1902 Otolithus (Corvina?) cirrhosoides – Schubert: 10, fig. 4. 1902 Otolithus (Umbrina?) plena – Schubert: pl. 10, fig. 6. 1981 Umbrina cirrhosoides (Schubert, 1902) – Nolf: pl. 3, fig. 10. 1993 Umbrina cirrhosoides (Schubert, 1902) – Schwarzhans: figs 124–125. 2010 Umbrina cirrhosoides (Schubert, 1902) – Jovanović et al.: pl. 2, fig. 3. 2013 Umbrina cirrhosoides (Schubert, 1902) – Schultz: pl. 90, figs 3–4. 2018 Umbrina cirrhosoides (Schubert, 1902) – Bannikov, Schwarzhans and Carnevale: fig. 9A–B. Material examined. 25 specimens, Pannonian E, Inzersdorf, coll. Huimann, NHMW-GEO-1974-1684-0154, 0155, 0160. Remarks. Umbrina cirrhosoides is known from the Central Paratethys since the late Badenian and throughout the Pannonian of Lake Pannon. Umbrina subcirrhosa (Schubert, 1902) Fig. 8AA–AF 1902 Umbrina subcirrhosa – Schubert: pl. 10, fig. 3. 1906 Otolithus (Sciaenidarum) schuberti – Lörenthey: pl. 2, fig. 6. 1993 Umbrina subcirrhosa Schubert, 1902 – Schwarzhans: figs 103–107. 2013 Umbrina subcirrhosa Schubert, 1902 – Schultz: pl. 90, fig. 6. 2018 Umbrina subcirrhosa Schubert, 1902 – Bannikov, Schwarzhans and Carnevale; fig. 9C–F (see there for further references). Material examined. 9 specimens, Pannonian E, Inzersdorf, coll. Huimann, NHMW-GEO-1974-1684-0161. Remarks. Umbrina subcirrhosa is an uncommon but long-ranging species from the Karpatian throughout the Pannonian (Bannikov et al. 2018). Because of its compressed shape, the concave outer face, and the narrow intercaudal space, it can be recognized even with relatively small specimens (Fig. 8AD–AF). Umbrina sp. Fig. 8AG–AH Material examined. 2 specimens, Pannonian E, Inzersdorf, coll. Huimann, NHMW-GEO-1974-1684-0162. Remarks. Two specimens are similar to Umbrina subcirrhosa but differ in the relatively small ostium and wide intercaudal space (43% of SuL vs. 25–28% of SuL). Genus indet. Sciaenidae indet. juv. Material examined. 250 specimens, Pannonian E, Inzersdorf, coll. Huimann, NHMW-GEO-1974-1684-0136, 0137, 0141, 0146, 0147, 0156, 0159, 0163, 0164, 0168, 0169, 0170. Remarks. The by far largest proportion of sciaenid otoliths from Inzersdorf are small, in the range of 1.5 to about 5 mm in length, and cannot be reliably assigned to any of the species mentioned above. Relatively small specimens of Umbrina subcirrhosa and sometimes also from Trewasciaena kokeni from a size of about 4 mm in length can be recognized. These small, unidentifiable sciaenid otoliths may therefore primarily represent Chaoia angulata, but some juvenile specimens of Trewasciaena kokeni and Umbrina cirrhosoides could also be contained in this category. Skeletal remains (a brief summary) Skeletal remains of bony fishes have commonly been recorded from the Pannonian of the Vienna Basin, mostly isolated bones, teeth, and more or less complete articulated skeletons (Schultz 2013). Many pharyngeal teeth of cyprinids have been described (e.g., Weinfurter 1950, 1954; Böhme 2002; Schultz 2013), mostly from Pannonian F–H, but some also from Pannonian B and E (Schultz 2013). Other teeth and dentary fragments have been reported from sparids, sciaenids and a supposed scombrid: Pelamycybium partschi (Münster, 1846). Pectoral fin spines have been described from two siluriform taxa (Schultz 2013). A dentary fragment of Lates sp. was recorded from the Pannonian C by Schultz (2013). As for articulated skeletons, Přikryl et al. (2021) described a well-preserved complete articulated skeleton with otoliths in situ pertaining to Trewasciaena kokeni from the Pannonian E of the Czech Republic. Other than that, several incomplete skeletons have been described as pertaining to Gadiformes – Lota hulai and Phycis suessi – and a Moronidae indet. tail fragment. Weinfurter (1954) commented on a skeletal imprint originally mentioned by Fuchs (1871) as a percoid, probably Beryx, that it might instead represent a Sciaenidae. According to information provided by M. Harzhauser, several articulated bony fish skeletons exist in the Natural History Museum of Wien (NHMW) from the Pannonian that require revision. This will be the task of a follow-up project to this study. It is thought that some of the discrepancies between the identifications of otoliths and skeletal remains can be resolved in such review. Fish evolution in Lake Pannon Lake Pannon formed a large endorheic inland water body during the Late Miocene over terrain that earlier constituted the Central Paratethys. The water chemistry in Lake Pannon is often described as “Caspi-brackish” that is mesohaline or even oligohaline (Gulyas 2001; Müller et al. 2007). Recent data on sulfur isotopes, however, suggest a near-marine sulphate content (Lin et al. 2023), and Harzhauser et al. (2024) assumed polyhaline conditions above 20 psu based on the occurrence of stenohaline tunicates. The lake water at great depth (below 100 to 200 m) was Annals of the Natural History Museum Vienna 126 2025, 81–109 anhmw.pensoft.net 101 commonly dysoxic (Lin et al. 2023) and probably avoid of a bathydemersal freshwater fish fauna. Lake Pannon is also known for the rapid, forced endemic evolution of its biota, particularly bivalves such as Dreissenidae and Cardiidae (e.g., Papp 1951; Geary et al. 2000; Müller et al. 2007; Harzhauser and Mandic 2010; Neubauer et al. 2013, 2016), which are widely used for biostratigraphic purposes. It was furthermore discussed how the endemic Lake Pannon fauna spilled over into the Eastern Paratethys during the late Pannonian and thus gave rise to the present-day endemic Ponto-Caspian mollusk fauna (Müller et al. 2007; Muzek et al. 2023). With the current review of the otolith-based fish fauna in the western part of Lake Pannon, some of these aspects can be elucidated from a different perspective. Even though our knowledge of otoliths from the Late Miocene and Pliocene of the Paratethys (including Lake Pannon) is far inferior to that of the mollusks that have been accumulated through intense research over many decades, it may still add important facets to the fascinating history of the biota in this unique water body. In respect to the Pannonian, the richest otolith-based fish fauna so far has been retrieved from the Pannonian E of the Vienna Basin, the time of the maximum extent of Lake Pannon. Data from the Pannonian B, C, F, and H and the underlying late Sarmatian s.s. are comparatively scarce and sometimes originate from different environments (fluviatile, freshwater lakes, etc.). The first observation to be made from the fish fauna of the Pannonian E of Brunn am Gebirge, Vösendorf, and Inzersdorf, which is based on a few thousand specimens, is that it is relatively lean in species that actually lived in the lake. In the category of firm Lake Pannon fishes (Pannonian B through E), one can count 16 species distributed among the families Clupeidae (1 species), Gadidae (2 species), Gobiidae (5 species), Atherindae (1 species), Mugilidae (1 species), Moronidae (2 species), and Sciaenidae (4 species). Fish remains that probably represent freshwater fishes are excluded from this count, including those probably brought in by riverine discharge or amphidrom predator activities. This is a lower diversity level than observed in the Badenian, Sarmatian s.s., or time-equivalent strata in the Eastern Paratethys (Radwańska 1992; Schwarzhans et al. 2017a-e; Bratishko et al. 2015, 2023). It clearly speaks for the Pannonian lake system in the Vienna Basin lacking the environmental diversity necessary for supporting a highly diverse fish fauna. Pannonigadus, Chaoia angulata and Trewasciaena kokeni are all endemic in Lake Pannon, but Pannonigadus at least has roots in the late Sarmatian s.s. However, the long ranges of these and many more otolith-based species in Lake Pannon are a clear indicator that the rapid speciation observed in mollusks in the lake is not mirrored in fishes. Of course, other parts of Lake Pannon that have not been adequately studied for otoliths could have provided more suitable environmental diversity for a greater diversity in fishes. When comparing the Lake Pannon fish fauna with the extant fish population in the Caspian Sea, it is clear that the fish diversity in Lake Pannon was higher on the familial level, although it was much lower on the species level. In the Caspian Sea, endemics are carried by the Gobiidae and, to a lesser extent, the Clupeidae. These are fishes, the Gobiidae in particular, that are able to adapt to changing water salinities and even thrive in such settings and radiate over short periods of time. Other groups like the Gadidae, Atherinidae, Sciaenidae, and more were also present in the Late Miocene of the Eastern Paratethys and developed endemics in the basin (Bratishko et al. 2023) but became extinct at some stage. The fish fauna of Lake Pannon, as far as is known, did not contain fully marine, stenohaline fishes. This forms a contrast to the time-equivalent fish faunas from the Eastern Paratethys which contained true stenohaline marine fishes well into Bessarabian times (Bratishko et al. 2023). All fish families represented in Lake Pannon are able to tolerate some reduction of salinity, i.e., are euryhaline. Several of them, however, are not present today in the Caspian Sea or rather became extinct at some time, and I would therefore postulate that the waters of Lake Pannon (up to at least Pannonian E) were less brackish than todays “Caspi-brackish” regime. Since true stenohaline marine fishes are missing, a polyhaline to mesohaline water chemistry is most likely. Another aspect for consideration is the level of endemism observed in the Lake Pannon fish fauna. Eight species (i.e., 50 %) have not been found outside in time or space from the Pannonian of Lake Pannon. This includes the clupeid (Sardina trolli), one gadid (Gadiculus weinfurteri), two gobies (Ponticola planodorsalis and P. wiesenensis), the two moronids (Eomorone kuehni and Morone serrata), and two sciaenids (Chaoia angulata and Trewasciaena kokeni). The two sciaenid species, however, appear to have migrated into the Eastern Paratethys and Trewasciaena kokeni even into the Mediterranean (Bannikov et al. 2018) during the Late Miocene–Early Pliocene. This may appear to be a relatively high degree of endemism, but when compared to the likewise secluded Eastern Paratethys it is still low. The time-equivalent Bessarabian of the Eastern Paratethys contains only endemic species (36 species; Bratishko et al. 2023), and this assemblage represents the third wave of forced endemism in the Eastern Paratethys since late Badenian (Konkian) times, each with more than 35 species (Bratishko et al. 2023). Many of the fishes identified by means of otoliths from Lake Pannon were already present in the Central Paratethys during the late Sarmatian s.s., including three species of the Gobiidae that are generally apt for particularly rapid speciation (Neogobius sculptus, Ponticola dorsorostralis, and Protobenthophilus squamatus), and some even from the lower Sarmatian s.s. or Badenian (Fig. 9). Few sciaenids extend into the late Pannonian and into the Pliocene of the Dacian and Pontian basins (Bannikov et al. 2018). These would be candidates that could have migrated into the Eastern Paratethys from Lake Pannon during the late Pannonian (e.g., Chaoia angulata, Trewasciaena kokeni, and Umbrina cirrhosoides; see Bannikov et al. 2018). None of those lineages, however, have persisted until today in the Ponto-Caspian Basin. anhmw.pensoft.net Werner Schwarzhans: Fish-life in the Late Miocene Lake Pannon (Vienna Basin)102 However, the fish fauna in Lake Pannon is poorly studied for the late Pannonian and could be biased by sampling algorithms (too large mesh sizes) that may have favored collecting of the large sciaenid otoliths (Fig. 9). Neither Bosnakoff and Katona (2012) nor Jovanović et al. (2010) reported any gobiid otoliths but only depicted the relatively large otoliths of sciaenids and gadids. There is no reason why gobies should not have been co-occurring, and their lacking in late Pannonian collections may therefore be arbitrary. For instance, Pana (1982) and Brzobohatý and Pana (1985) have documented many small goby otoliths from the Pannonian B through D from Romania. However, these otoliths are extremely small and the documentation extremely schematic, and no meaningful interpretation can therefore be done beyond family level. The Caspian Sea of today contains at least five distinct endemic clades of fishes, two in the Clupeidae (Alosa, subgenus Caspialosa, and the endemic genus Clupeonella) and three in the Gobiidae (the Neogobius-Ponticola group, the Benthophilini, and certain genera of the “sand gobies” like Knipowitschia and related genera), all of which with endemic genera and species. The only clupeid in Lake Pannon, Sardina trolli, is not related to the extant endemic Ponto-Caspian clupeids of the genera Alosa Figure 9. Stratigraphic ranges of otolith-based Lake Pannon fishes based on current study and referenced literature. Freshwater fishes not shown. Annals of the Natural History Museum Vienna 126 2025, 81–109 anhmw.pensoft.net 103 and Clupeonella. Relatives of the two latter genera are known in the Eastern Paratethys since late Badenian and Bessarabian, respectively (Bratishko et al. 2015, 2023). Turning to the masters of adaptation and endemic evolution in fishes, the Gobiidae, it is true that one observes species of the endemic Ponto-Caspian genera Neogobius, Ponticola, and Protobenthophilus in Lake Pannon. Neogobius and Ponticola are typical euryhaline genera and are mostly missing in the marine environments of the Eastern Paratethys, except for their earliest occurrence, that is, in the Konkian (late Badenian) of Kazakhstan (Bratishko et al. 2015). Ponticola dorsorostralis is also known from coeval brackish environments of Ukraine, in the Eastern Paratethys, along with two other Ponticola species (Bratishko et al. 2017). Protobenthophilus squamatus was first identified based on an articulated skeleton with otolith in situ in the early Sarmatian s.s. in Croatia (Schwarzhans et al. 2017c). Some of the endemic lineages in the “sand gobies,” for instance Hyrcanogobius, are first identified in the Bessarabian of the Crimea (Bratishko et al. 2023). Thus, the idea that the extant Caspian fauna evolved from a former Lake Pannon fauna that at some stage spilled over into the Ponto-Caspian Basin is not supported in the evolution of fishes. It may be that some Lake Pannon fishes migrated at some time into the Eastern Paratethys, mainly of the Sciaenidae, but these did not give rise to the present day endemic fauna in the Caspian Sea, which is rich in endemic gobies and clupeids. In respect to the five extant endemic clades of clupeids and gobies in the Caspian Sea, it is not necessary to invoke migration from Lake Pannon during the Pontian, as was assumed for mollusks (Müller et al. 2007), and in fact there are certain counter-indications in the fish faunas of the Eastern Paratethys. Instead, there are indications that the stock of the extant endemic Caspian fishes originated in the late Badenian to Sarmatian (Bessarabian) in the Paratethys but, during the early phases in the Eastern Paratethys, occurred mainly in marginal marine to brackish settings. It is only the Benthophilini for which much of the origination and evolution has remained elusive. Rapid endemic speciation in fully marine environments occurred in different clades, and they became extinct at a later time (Reichenbacher and Bannikov 2022, 2023; Schwarzhans et al. 2022; Bratishko et al. 2023). Fish communities in the Pannonian of the Vienna Basin and their paleoenvironmental relevance The paleoenvironmental development in Lake Pannon has been the subject of much research: for example, Papp (1951), Geary et al. (2000), Harzhauser et al. (2002), Müller et al. (2007), Neubauer et al. (2016), and Magyar (2021). The paleoenvironmental role of the Vienna Basin in Lake Pannon has been elucidated by, for instance, Harzhauser et al. (2004), Harzhauser and Tempfer (2004), and Harzhauser et al. (2022, 2024). Since the great majority of otoliths studied here are from the Vienna Basin, I focus on the paleoenvironmental evaluation of the most intensely studied intervals in the Vienna Basin. During the maximum extent of Lake Pannon in the Pannonian E, the Vienna Basin formed a part of the lake, sheltered to the east by the Leitha Mountains, which formed an island at the time (Magyar et al. 1999; Harz hauser et al. 2004; Magyar 2021). Rivers were discharging into the basin along the basin axes and from the west (Harzhauser et al. 2004). The Sciaenidae were the dominant family in this environment (67% at Inzersdorf), containing four species, two of which have been endemic in Lake Pannon (Chaoia angulata and Trewasciaena kokeni). Of all otoliths at Inzersdorf, 47.5% are small, unidentifiable sciaenid otoliths from juvenile specimens. This is a high percentage compared to other localities with a high abundance of sciaenids, but a sufficient number of well-preserved large specimens occurred to facilitate recognition of the species. Other locations in the Pannonian Basin such as Tinnye (Pannonian B) or the localities studied by Pana (1982) did not contain sciaenids. Trewavas (1977: 259) stated that the Sciaenidae are particularly “common in warm shallow seas and estuaries, especially where great rivers enter the sea.” I therefore assume that the deltas as shown by Harzhauser et al. (2004, 2024) in the vicinity of the localities Brunn am Gebirge, Vösendorf, and Inzersdorf played an important role for the abundance of sciaenid otoliths in these locations (Fig. 10). In view of the thriving mollusc fauna in Lake Pannon it is a question whether any of these fishes were durophagous and actually feeding on them. Weinfurter (1954) commented about very common molariform teeth at Brunn am Gebirge and Vösendorf that would be typical for durophagy in fishes (Purnell and Darras 2016). Such teeth are traditionally associated with the Sparidae (e.g., Weinfurter 1954), which, however, is not consistent with the lack of sparid otoliths in the Pannonian. The origin of these teeth remains unresolved for now but it clearly shows that some type of durophagous fishes were living in Lake Pannon and were actually common at places. It is remarkable in that respect that certain sciaenids that feast on mollusks have developed similar durophagous teeth on the pharyngeal jaws, e.g., Pogonias cromis (Linnaeus, 1766) from the western Atlantic (Ziv et al. 2020). The species of Umbrina are known to feed on bottom living shrimps, worms and other bottom living invertebrates (Chao 1986). The articulated skeleton of Trewasciaena kokeni has the pharyngeal jaw not exposed (Přikryl et al. 2021). Böhme (2002) described stout, cone-shaped teeth from Götzendorf that she related to the common sciaenid otoliths from that location (Chaoia angulata). These teeth could indicate an omnivorous feeding habit that could include mollusks. In any case, resolution can only be expected when adequate articulated skeletons with exposed pharyngeal teeth have been found. Böhme (2002) also identified a freshwater fish of the family Cyprinidae adapted to molluscan diet (Barbus vindobonensis Böhme, 2002) at Götzendorf. anhmw.pensoft.net Werner Schwarzhans: Fish-life in the Late Miocene Lake Pannon (Vienna Basin)104 All other euryhaline families at Inzersdorf occur in percentages between 3% and 12%. In decreasing abundance, these are the Moronidae, Gobiidae, Atherinidae, Clupeidae, Gadidae, and Mugilidae (Table 1). The Moronidae and Atherinidae may also have benefited from a nearby river estuary. Surprisingly, perhaps, is the total absence of the Pleuronectiformes, which are known to be able to tolerate reduced salinities. Otherwise, pleuronectiform otoliths are common in the Middle Miocene of the Paratethys and the Upper Miocene of the Eastern Paratethys. In addition to the presumed genuine Lake Pannon fishes, one observes singular occurrences of fishes that must have lived in freshwater environments and thus do not match the sheltered polyhaline lake setting. These are unique otoliths of two cyprinid species at Inzersdorf and Lates brunnensis at Vösendorf. I assume that these rare remnants of freshwater fishes in Inzersdorf and Vösendorf were brought in either by fluviatile discharge or by the activities of migratory or amphidrom predators. All in all, Inzersdorf contained the highest diversity of fishes observed in any of the Pannonian localities so far known. The situation changed drastically during the Pannonian F when the lake had shifted eastward of the Leitha Mountains, and the Vienna Basin transformed into marshland and floodplain environments (Harzhauser et al. 2004, 2024). The Palaeo-Danube river system was meandering through the marshland, cutting through a gate around the Leitha Mountains and discharging into the Danube Basin. Götzendorf and Stixneusiedl have been located along the lower reaches of the Palaeo-Danube system during the Pannonan F. Elsewhere, short-lived freshwater lakes existed away from the Palaeo-Danube, for instance at Eichkogel (Weinfurter 1950). Götzendorf has yielded a rich but monotonous otolith-based fish fauna exclusively containing otoliths of Chaoia angulata. However, Böhme (2002) analyzed the skeletal elements and teeth from Götzendorf which were rich in species of the Cyprinidae including one adapted to molluscan diet (see above), a Cobitidae, two Siluriformes, a Gobiidae and a Sciaenidae. Thus, the Götzendorf fish fauna was apparently more diverse than hinted by otoliths alone. Figure 10. Idealized block diagram depicting fish life in Lake Pannon in the Vienna and adjacent Danube Basin. Taxa in square brackets are based on skeletal remains as taken from referenced literature. A. Situation during the maximum lake extension phase of Pannonian E; B. Situation during Pannonian F–H. Annals of the Natural History Museum Vienna 126 2025, 81–109 anhmw.pensoft.net 105 Chaoia angulata is also an important element at Stixneusiedl, but here it is accompanied by similarly common freshwater fishes, i.e., Toxopyge bradicae (Gobiidae) and Miovalencia cf. chios (Valenciidae). Toxopyge is an extinct freshwater goby that is well known and common in the Early and Middle Miocene Dinarid lake system (Bradić-Milinović et al. 2019, 2021). The species from Stixneusiedl represents the latest occurrence of the genus so far known. Miovalencia cf. chios is another interesting species, since it has originally been described from time-equivalent freshwater environments in the vicinity of the Aegean, on Chios. The most likely explanation for the co-occurrence of freshwater fishes and Chaoia angulata from the polyhaline lake environment at Götzendorf and Stixneusiedl is that these localities were in the oligohaline to freshwater zone of the lower Palao-Danube reaches and while the freshwater fishes inhabited this environment Chaoia angulata was an amphidromous species able to move up into rivers for a certain distance (Fig. 10). Since Chaoia angulata is the only sciaenid found at Götzendorf and Stixneusiedl, one must assume that the other three sciaenid species, and most other lacustrine fishes, were not able to move up rivers. In addition, a single specimen of Atherina suchovi has been found at Stixneusiedl; and atherinids also can be amphidromous. Further to the east, in the Danube Basin at the Hungarian localities Doba (Bosnakoff and Katona 2012) and Tihany (Lörenthey 1906), the same Lake Pannon fauna continued that lived in the Pannonian E in the Vienna Basin. However, these localities appear to be leaner in species (Sciaenidae and Pannonigadus), but this could also be due to sampling bias and/or smaller sample sizes. A completely different faunal association was described by Weinfurter (1950) from the Pannonian H of Eichkogel. This association is dominated by Umbra praekrameri and rare Esox, Perca, and gobies, probably of Ponticola and Toxopyge bradicae. The extant Umbra krameri Walbaum, 1792, lives in the Danube drainage from Vienna to the delta and in the Dniester drainage (Froese and Pauly 2024). It inhabits slowly flowing and stagnant waters with dense vegetation (Froese and Pauly 2024). This fish association is thus characteristic for a freshwater lake away from the river and influence from Lake Pannon (Fig. 10). This is congruent with the geography of that time, when the northern shore of the lake had already moved far into the Pannonian Basin (Magyar et al. 2013). Conclusions and Outlook The review of the otolith-based fish fauna from Lake Pannon of the Vienna Basin in Austria (and some additional data from Hungary) has revealed a specific compositional frame and evolution that differed in some aspects from that so well-known from mollusks. - The dominant fish family in Lake Pannon during its maximum extent was the Sciaenidae, with more than 50% in the localities of the Pannonian E in the Vienna Basin. - The total composition is relatively lean in fish species, with 29 species in all environments of the Vienna Basin and 16 species considered to represent true lake fishes. - All fishes in Lake Pannon were euryhaline; stenohaline marine fishes were missing. This supports a polyhaline to mesohaline water chemistry. - 50% of the lake fishes were endemic; the other 50% had roots in the Sarmatian s.s. or even the Badenian. This ratio indicates a relative evolutionary stasis of the fishes in Lake Pannon, which forms a stark contrast to the rapid adaptive radiation known from mollusks or the waves of forced endemism in fishes observed in the coeval Eastern Paratethys. Otoliths were also retrieved from other, slightly younger, environmental settings in the Vienna Basin. - Localities in the lower reaches of the Palaeo-Danube River from an oligohaline to freshwater setting showed a mixture of fishes that presumably lived stationary in that environment (a Cyprinodontidae and a Gobiidae) and an amphidromous sciaenid (Chaoia angulata) that apparently was able to migrate into streams for some distance. Table 1. Distribution of main faunal components in otolith associations of the studied localities. Percentages may add up to less then 100%. Characterization of salinity tolerance from literature about extant fishes (e.g., Froese and Pauly 2024). Tinnye Inzersdorf Götzendorf Stixneusiedl Eichkogel* fully marine polyhaline mesohalyne oligohalyne freshwater Pannon B Pannon E Pannon F Pannon F Pannon H Clupeidae 5.30% Umbridae 82.70% Gadidae 4.40% Gobiidae 100.00%** 9.70% 47.80% 10.30% Atherinidae 7.40% 1.40% Mugilidae 3.00% Valenciidae 20.30% Moronidae 12.10% Sciaenidae 67.70% 100.00% 30.40% * - after Weinfurter (1950) ** - including Eleotridae.