The pre-Taghanic (Givetian, Middle Devonian) ecosystems of Miłoszów (Holy Cross Mts, Poland)

Abstract

The middle and upper parts of the Skały Fm, Early to Middle Givetian in age, were investigated in four sections at Miłoszów Wood in the Łysogóry Region (northern region of the Holy Cross Mountains, central Poland). The dating is based on conodonts (Polygnathus timorensis Zone to the later part of the Polygnathus varcus/Polygnathus rhenanus Zone; early Polygnathus ansatus Zone cannot be excluded) and spores (Ex1-2 subzones) and, coupled with cartographic analysis and geophysical investigation, allows correlation within the strongly faulted succession. Significant lateral facies variations within the carbonate ramp depositional system in comparison with the better studied Grzegorzowice-Skały section, about 3 km distant, are documented, thanks to conodont-based correlation of both successions. Foraminifers, fungi, sponges, rugose and tabulate corals, medusozoans, microconchids and cornulitids, polychaetes (scolecodonts), molluscs (bivalves, rostroconchs, and gastropods), arthropods (trilobites and ostracods), bryozoans, hederelloids, ascodictyids, brachiopods, echinoderms (mostly crinoids, rare echinoids, holuthurians, and ophiocistoids), conodonts, fish, plants (prasinophytes, chlorophycophytes, and land plant spores), and acritarchs are present. Brachiopods are the most diverse phylum present (68 species), other richly represented groups are bryozoans and echinoderms; in contrast, cephalopods and trilobites are low in diversity and abundance. The muddy, middle to outer ramp biota (200 marine taxa, including 170 species of marine animals, 22 photoautotrophs, 6 forams) represents a mixture of allochthonous shallower-water communities (upper BA3), including storm-and possibly tsunami-affected coral mounds, and autochthonous deep-water soft-bottom brachiopod (e.g., Bifida-Echinocoelia) communities (BA 4-5). The richness and diversity of the Miłoszów biota is relatively high, comparable with other approximately coeval pre-Taghanic ecosystems during the Devonian climatic deterioration (cooling). Preliminary data indicate that in the Holy Cross Mountains, no large-scale replacement of brachiopod (and probably many other benthic ones, like crinoids) communities took place between the Early-Middle Givetian and the Early Frasnian, in contrast to the demise of the Hamilton/ Upper Tully fauna in the Appalachian Basin. Such a similarity of pre-and post-Taghanic faunas does not exclude the occurrence of environmental perturbations and transient community turnovers, caused by immigrations during the Taghanic Biocrisis, but evidences the successful recovery of the indigenous biota.

Palaeoecology of calcified microfossils from the Lower Devonian (Pragian-Emsian) of Sierra Morena (SW Spain)

“…In the Emsian Peñón Cortado section, samples collected from the units 1, 12, and 17-20 contained various Girvanella species, a calci ed microproblematic Rothpletzella sp., and the green alga Bediaella hispanica gen. nov. sp. nov. (units [17][18][19][20].…”

“…Studied assemblages of calcareous microfossils from the Lower Devonian of Sierra Morena might mirror regional and global sea level changes. The two main occurrences in the Pragian Peñón Cortado section (units [17][18][19][20] and in the Emsian Guadámez-2 section (units G 18-G 20) probably mark peaks of regressive cycles observed during the Pragian and Emsian which were separated by the transgression near the Pragian/Emsian transition (e.g., Johnson et al 1985Johnson et al , 1996Chlupáč and Kukal 1986;Flajs andHüssner 1996, Keller, 1997)…”

Frasnian (Upper Devonian) Brachiopods From Armenia: Biostratigraphic and Palaeobiogeographic Implications

“…However, the examination of Abrahamyan's species revealed the presence of frills, an ornamental feature that was considered unknown in Struve's (1966) subgenus by Copper (2002), but their presence in this subgenus was challenged notably by Komarov (1997), Halamski & Baliński (2013) and Halamski et al (2022). As Baliński & Halamski (2023) noted the existence of species presenting intermediate characters that cannot be assigned de昀椀nitely to one of the subgenera previously recognised within Atrypa (see Copper 2002) or to Kyrtatrypa Struve, 1966, we presently follow Komarov's (1997) subgeneric assignment, pending a reassessment of some features used in (sub) generic distinctions among atrypides, which is well beyond the scope of this work.…”

First occurrence of the genus Sphenothallus Hall, 1847 (Cnidaria) in the Carboniferous of the Dnipro-Donets Depression, Ukraine

“…Macroscopic, elongate, tubicolous phosphatic fossils assigned to the genus Sphenothallus Hall, 1847 are known in Paleozoic marine sediments in many parts of the world, including North America (Mason & Yochelson, 1985;Bodenbender et al, 1989;Frey, 1989;Van Iten et al, 1992;Neal & Hannibal, 2000 and references there), Greenland (Peel, 2021), South America (Clarke, 1913;Taboada, 1997;Van Iten et al, 2019), Africa (Van Iten et al, 2016), Europe (Nathorst, 1883;Fauchald et al, 1986;Brood, 1988;Fatka et al, 2012;Stewart et al, 2015;Vinn & Kirsimäe, 2015;Vinn & Mironenko, 2021;Halamski et al, 2022 and references in these works), and Asia (Choi, 1990;Zhao et al, 1999;Yi et al, 2003;Wang et al, 2003;Li et al, 2004;Van Iten et al, 2013;Muscente & Xiao, 2015;Dzik et al, 2017;Chang et al, 2018 and references therein).…”