A Review of Otoliths Collected by W. Weiler from the Badenian of Romania and by B
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Cainozoic Research, 17(2), p. 167-191, December 2017 167 A review of otoliths collected by W. Weiler from the Badenian of Romania and by B. Strashimirov from Badenian equivalents of Bulgaria Werner Schwarzhans Ahrensburger Weg 103, 22359 Hamburg, Germany, and Natural History Museum of Denmark, Zoological Museum, Universitetsparken 15, 2100 Copenhagen, Denmark; e-mail: [email protected]. Received 22 September 2017; revised manuscript accepted 24 October 2017. The early Badenian represents the last period of unrestricted marine connectivity with adjacent oceans in the history of the Paratethys. A comprehensive capture of the fish fauna roaming the early Badenian seas of the Paratethys is necessary to fully comprehend the endemic evolution that took the stage following its isolation during the Serravallian (late Badenian in the Central Paratethys and Karaganian and Konkian in the Eastern Paratethys). Many publications have dealt with early Badenian otolith-based fish assemblages in the northern and western parts of the Central Paratethys, but coeval faunas from the southeastern Central Paratethys and the Eastern Paratethys are scarce and in dire need of revision. Here I present a review of the rich otolith assemblage described by Weiler in 1950 from the early Badenian of Coşteiu de Sus and Lăpugiu de Sus in Romania and update their identifications. The review results in the recognition of a number of new species, i.e. Aulopus costeiensis n. sp., Bathypterois solidus n. sp., Myripristis lobata n. sp., Lesueurigobius magniiugis n. sp., Weilerigobius lapugiensis n. gen., n. sp., Callanthias transylvanicus n. sp. and Pagellus schuberti n. sp. A comparison with the well known otolith- based fish faunas from the northern and western Central Paratethys reveals good correlation, but nearly one quarter of all fish species are not recorded from there. The most likely explanation of this phenomenon is a latitudinal / climatic difference and probably a greater influence of Eastern Paratethyan elements in Romania. A much smaller collection from Badenian equivalent strata of wells in Bulgaria, inherited from B. Strashimirov, was also studied. It contained the first fossil record of the gobioid family Microdesmidae - Microdesmus paratethycus n. sp. This collection is dominated by very small otoliths that appear to have been collected in the course of search for microfossils and hence shows many small fish representatives missing from the Romanian locations. The role of collecting bias versus potential faunal differences is discussed with this example. It is concluded that the knowledge of the early Badenian otolith-based fish fauna of the Central Paratethys is much improved, albeit far from being completely assessed. Important additional data, however, are more likely to be expected from coeval Eastern Paratethyan strata when comprehensively collected and older material being reviewed, if still available. KEY WORDS: Central Paratethys, Eastern Paratethys, Teleostei, Aulopiformes, Gobioidei. Introduction the Pannonian Basin (Sant et al., 2017). The southern and eastern regions of the Pannonian Basin were flooded later The rich early Badenian faunas from Coşteiu de Sus (= than the northern and western regions during the early Kostej) and Lăpugiu de Sus (= Lapugy) have been known Badenian, transgressing over a non-marine sediment se- since the late 19th century (Hoernes &Auinger, 1884 and quence of early to middle Miocene age (Mandic et al., Boettger, 1902; see Gaal, 1912 and Landau et al., 2009). 2012). The early Badenian strata of Coşteiu de Sus and The molluscs particularly are known for their exceptional Lăpugiu de Sus thus would have been deposited during preservation and have also been the subject of many pub- a time interval belonging to the upper Lagenidae Zone lications in recent times (Caze et al., 2010; Kronenberg as shown in Pezelj et al. (2013) and be more or less time & Harzhauser, 2011; Harzhauser & Kronenberg, 2013; equivalent to the Tshokrakian (Ćorić et al., 2009) be- Tămaș et al., 2013). tween about 14.5-14.0 Ma. The chronostratigraphic correlation of the middle to late First finds of otoliths have been mentioned occasionally, Miocene sequences of the various Paratethyan subba- for instance by Prochazka (1893) and Schubert (1906). sins is chronically complex and currently under review The first figured otoliths from Lăpugiu de Sus are found and re-evaluation. Recently, the basal Badenian flooding in Schubert (1912), but it is in the monograph of Weiler event has been identified as a diachronous event across (1950) based on Boettger’s collection that a comprehen- 168 Schwarzhans - Review of otoliths, Badenian of Romania (col. Weiler) and Bulgaria (col. Strashimirov). sive description of otoliths of both locations has been Also included in this study are some otoliths collected achieved. Later Rado (1981) published a summary review from wells in the Eastern Paratethys in Bulgaria by the of otoliths of both locations and other Langhian localities late B. Strashimirov and covering a similar time interval in southern Romania (in Romanian), but she did not add from Tarchanian to Konkian. The result of the revision new taxonomic records. Nolf (1981) revised the material of Weiler’s specimens is summarized in Table 1. The fol- of Schubert, but could not find all specimens recorded by lowing systematic part only contains descriptions of new him and therefore left several as of doubtful nature. Nolf species and species for which a revision of the taxonomic also reviewed Weiler’s types from 1950 and offered revi- allocation is proposed (see also Table 1). Specimens men- sions for the taxa in his handbooks on otoliths in 1985 and tioned by Schubert (1912) from Lăpugiu de Sus are also 2013. A comprehensive review of the material of Weiler’s listed in Table 1, but have not been subject of this review. monograph, however, was never performed or published. The result of the specimens collected by Strashimirov is The purpose of this study is to update the interpreta- summarized in Table 2. These otoliths originated from tion of the otolith collections from Coşteiu de Sus and wells and apparently have been obtained while searching Lăpugiu de Sus described by Weiler, since it represents for microfossils in a very fine fraction. For the most part one of the largest and most diverse otolith assemblages it comprises unpublished material. from the Badenian of the southern Pannonian Basin. I soon realized that it would contain fishes not present in the well known otolith associations of the Vienna Ba- Material and methods sin and the northern Pannonian Basin, possibly because of latitudinal differences. Also, it is of importance to Weiler’s otoliths are stored at the Natur-Museum und achieve a good understanding of the Langhian otolith as- Forschungsinstitut Senckenberg in Frankfurt/Main, semblages of the Paratethys because they represent the Germany (SMF) under the registry P. (Pisces) and the last truly marine fish fauna spread across the basin with- newly catalogued ones under the registry PO. (Pisces, out geographic obstacles prior to the final separation of otoliths). Strashimirov’s otoliths are housed at the Muse- the Paratethys and the onset of its endemic evolution. um of Geology and Paleontology, University of Mining Figure 1. Paleogeographic map of the Central Paratethys and adjacent seas during the early Badenian (after Sant et al., 2017); marine terrain shaded. Locations are marked with an asterisk: 1) Coşteiu de Sus and Lăpugiu de Sus in Romania, 2) wells in Bulgaria. Northing is vertical up. Cainozoic Research, 17(2), p. 167-191, December 2017 169 and Geology ‘St. Ivan Rilski’, Sofia, Bulgaria (UMG) Pseudophichthys sp. under the registry -X. Otoliths were photographed with Plate 1, fig. 1 a Canon EOS camera mounted on a Wild M400 photo- macroscope and remotely controlled from a computer. 1950 Otolithus [Congridarum] sp. – Weiler, pl. 5, fig. Individual photographs were stacked using the Helicon- 29; ? pl. 12, fig. 93. Focus software. Small inconsistencies were retouched 1992 Pseudophichthys sp. – Radwanska, text-fig. 15, pl. and contrast enhancement was occasionally performed 3, figs 10-12. with Adobe Photoshop. Several otoliths from Coşteiu 2014 Pseudophichthys sp. – Schwarzhans, pl. 1, fig. 3. de Sus have small, black, oily speckles on the surface which can not be removed without inflicting damage to Material examined – One specimen, SMF P.2791, Coşteiu the specimens. These speckles do not obliterate morpho- de Sus. logical features, but negatively affect the clarity of pho- tographs. To achieve better clarity of the pictures, these Description – Single otolith about 2.8 mm long with pigmentations have been selectively brightened during somewhat eroded and leached surface. Elongate shape, the digital retouching process. All otoliths are depicted OL:OH = 1.95 and OH:OT = 2.1. Anterior tip distinctly from the right side and show inner faces if not annotated sharper than broadly rounded posterior tip including the otherwise in the captions. Left side otoliths are reversed pronounced and broadly rounded postdorsal angle. Sul- for a better comparison and are annotated in the captions cus positioned on center of inner face and inclined at an with (r). angle of about 8°. Sulcus closed anteriorly and showing a distinct, uniform and oval colliculum terminating far The morphological terminology of otoliths was estab- from anterior rim of otolith. lished by Koken (1891) with amendments by Weiler (1942), Schwarzhans (1978) and for gobiids