Historical collections extend the knowledge on Late Jurassic decapod crustacean diversity from Brno-Stránská skála (South Moravian Region, Czech Republic)

The Brno-Stránská skála site is an erosional remnant of the Brno Carbonate Platform which formed during the Late Jurassic on the northern margin of the Tethys Ocean. The locality is a small hill designated as a national nature monument located in Brno, Czech Republic (Figure 1). Approximately 50 m thick succession of Jurassic limestone is exposed, representing mainly the middle-upper Oxfordian and possibly to the lowermost Kimmeridgian Transversarium to ?Bimammatum ammonite Zones (Hykš, 2025). The limestone yielded more than 130 species of marine fauna, including decapods (Oppenheimer, 1926; Hyžný et al., 2015; our study).
Due to the expansion of reefs during the Late Jurassic, many groups of marine invertebrates radiated and diversified, and decapod crustaceans became a significant component of marine environments (Vermeij, 1977; Sepkoski, 2000; Klompmaker et al., 2013). We investigated the paleontological collections from Stránská skála in the Moravian Museum and found 154 specimens of decapod crustaceans, including the specimen studied and figured by Oppenheimer (1926, tab. 1, fig. 1). The decapod collection consists of 90 (58 %) carapaces, 36 (24 %) isolated claw elements, and 28 (18 %) undeterminable fragments. Some specimens were found in association with corals. Eight species of decapods were identified, 4 of which were not reported in Czech Republic before. The identified anomuran species include Gastrosacus tuberosus (Remeš, 1985) and Gastrosacus limacurvus Robins, Feldmann & Schweitzer, 2013; the identified brachyuran species include Eodromites bernchrisdomiorum Klompmaker, Starzyk, Fraaije & Schweigert, 2020; Eodromites grandis (von Meyer, 1860); Goniodromites narinosus Franţescu, 2011; Goniodromites serratus Beurlen, 1929; Longodromites akainokkos Schweitzer, Lazăr, Feldmann, Stoica & Franţescu, 2017; and an as-yet undescribed species of Concavolateris Franţescu, 2011 (Figure 1). The assemblage is dominated by the representatives of Goniodromites, with G. serratus accounting for 43 % (n = 30) and G. narinosus accounting for 34 % (n = 24); the rest of the species are represented by a maximum of 5 specimens.
This material, together with the specimens of Gastrosacus wetzleri von Meyer, 1857 and Tuberosagalathea cf. T. neojurensis (Patrulius, 1959) reported by Hyžný et al. (2015) expands the total decapod diversity from Stránská skála from six species in five genera to ten species in six genera. To assess faunal similarities between Stránská skála and other Late Jurassic localities, we performed a non-metric multidimensional scaling (NMDS) analysis, using presence/absence data of 202 decapod crustacean species from 22 European localities dated to the Oxfordian to Tithonian. These sites expose either sponge-microbial or coral-dominated reef facies. The results show that Stránská skála is closest to the coeval locality of Topalu (Dobrogea, Romania), sharing the occurrence of E. grandis, Ga. tuberosus, Go. narinosus, L. akainokkos, and the species of Concavolateris; and to the localities of Bzów and Niegowonice (Kraków-Częstochowa Upland, Poland) sharing the occurrence of E. bernchrisdomiorum, E. grandis, Go. narinosus and Go. serratus.
Acknowledgements: The study was supported by the Slovak Research and Development Agency under contract no. APVV-22-0523, VEGA 2/0106/23, Grant of Comenius University no. UK/1073/2025, and the Ministry of Culture as part of institutional funding for long-term conceptual development of the Moravian Regional Museum research organization (MK000094862)