Stable isotope signatures of Middle Paleozoic ahermatypic rugose corals - deciphering vital effects, alteration patterns, and palaeoecological implications
Jakubowicz M, Berkowski B, López Correa M, Jarochowska E, Joachimski M, Belka Z (2015)
Publication Language: English
Publication Type: Journal article, Original article
Publication year: 2015
Journal
Book Volume: 10
Pages Range: e0136289 (29p.)
Journal Issue: 9
DOI: 10.1371/journal.pone.0136289
Abstract
This study investigates stable isotope signatures of five species of Silurian and Devonian deep-water, ahermatypic rugose corals, providing new insights into isotopic fractionation effects exhibited by Palaeozoic rugosans, and possible role of diagenetic processes in modifying their original isotopic signals. To minimize the influence of intraskeletal cements on the observed signatures, the analysed specimens included unusual species either devoid of large intraskeletal open spaces ('button corals': Microcyclus, Palaeocyclus), or typified by particularly thick corallite walls (Calceola). The corals were collected at four localities in the Holy Cross Mountains (Poland), Mader Basin (Morocco) and on Gotland (Sweden), representing distinct diagenetic histories and different styles of diagenetic alteration. To evaluate the resistance of the corallites to diagenesis, we applied various microscopic and trace element preservation tests. Distinct differences between isotopic compositions of the least-altered and most-altered skeleton portions emphasise a critical role of material selection for geochemical studies of Palaeozoic corals. The least-altered parts of the specimens show marine or near-marine stable isotope signals and lack positive correlation between δ13C and δ18O. In terms of isotopic fractionation mechanisms, Palaeozoic rugosans must have differed considerably from modern deep-water scleractinians, typified by significant depletion in both 18O and 13C, and pronounced δ13C-δ18O co-variance. The fractionation effects exhibited by rugosans seem similar rather to the minor isotopic effects typical of modern non-scleractinian corals (octocorals and hydrocorals). The results of the present study add to growing evidence for significant differences between Scleractinia and Rugosa, and agree with recent studies indicating that calcification mechanisms developed independently in these two groups of cnidarians. Consequently, particular caution is needed in using scleractinians as analogues in isotopic studies of extinct coral lineages. Answering some of the pertinent palaeoecological questions, such as that of the possibility of photosymbiosis in Palaeozoic corals, may not be possible based on stable isotope data.
Authors with CRIS profile
Matthias López Correa
Lehrstuhl für Paläoumwelt
Emilia Jarochowska
Lehrstuhl für Paläoumwelt
Michael Joachimski
Lehrstuhl für Geologie (Exogene Dynamik)
Involved external institutions
Poland (PL)How to cite
APA:
Jakubowicz, M., Berkowski, B., López Correa, M., Jarochowska, E., Joachimski, M., & Belka, Z. (2015). Stable isotope signatures of Middle Paleozoic ahermatypic rugose corals - deciphering vital effects, alteration patterns, and palaeoecological implications. PLoS ONE, 10(9), e0136289 (29p.). https://doi.org/10.1371/journal.pone.0136289
MLA:
Jakubowicz, Michal, et al. "Stable isotope signatures of Middle Paleozoic ahermatypic rugose corals - deciphering vital effects, alteration patterns, and palaeoecological implications." PLoS ONE 10.9 (2015): e0136289 (29p.).
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