The aim of this study is to investigate isotopic variability in archaeological (n=85) and modern (n=29) freshwater fish specimens from Switzerland. Here, carbon (δ13C) and nitrogen (δ15N) stable isotope ratio analysiswas performed on bone collagen samples of pike (Esox lucius), perch (Perca fluviatilis), barbel (Barbus barbus), roach (Rutilus rutilus) and carp (Cyprinus carpio) fromeleven archaeological (11th to 18/19th centuries CE) andmodern sites. The archaeological vs. modern fish data revealed significant isotopic differences for pike, perch and barbel (δ13Cp≤ 0.03; δ15Np≤ 0.008), and provides possible evidence for a temporal change in Swiss aquatic ecosystems from Medieval to modern times. In comparison to archaeological fish (δ13C mean ± SD; −23.3 ± 1.6‰; δ15N mean ± SD; 8.3 ± 1.8‰), the modern fish samples show decreased δ13C and increased δ15N values (δ13C mean± SD; −27.4 ± 2.3‰; δ15N mean± SD; 12.5± 4.1‰) that can be associated with anthropogenic effects: fossil fuel combustion, deforestation and organic waste in the form of sewage and fertilizers. The isotopic signatures of archaeological fish remains indicate a local fishery practice, but also the exploitation of distant fishing grounds and freshwater fish transportation. Furthermore, a diachronic isotopic trend is observed in young perch from sites in Basel, dating between the 12th and 15/16th centuries CE, and the isotopic data from the Rhine freshwater fish (18/19th century CE) suggests that a significant shift in the river's trophic state was possibly caused by organic pollution fromurban and industrial wastewater. This retrospective research illustrates possible natural processes and human activitieswhich can cause differences in fish stable isotope data and highlights the ability to elucidate changes in past bodies of water. Furthermore, this study provides an interpretative framework for additional palaeoenvironmental studies and modern restoration projects focused on freshwater ecosystems.
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RBINS Staff Publications 2016
We describe new material of the tristichopterids cf. Langlieria socqueti and cf. Eusthenodon wangsjoi and other unassignable tetrapodomorph remains from the upper Famennian locality of Strud, Belgium. Because of recent improvements in our tristichopterid knowledge, a new phylogenetic analysis is presented in addition to a paleobiogeographic analysis using the Bayesian binary Markov chain Monte Carlo (MCMC) statistical method. The origin of the whole tristichopterid clade is reconstructed with a very likely western European origin. Much of the early tristichopterid history took place in Euramerica. During the Late Devonian, tristichopterids most probably spread from Euramerica into Gondwana. The highly nested tristichopterid clade formed by Cabonnichthys burnsi, Mandageria fairfaxi, E. wangsjoi, Edenopteron keithcrooki, and Hyneria lindae most likely differentiated in Australia. Then dispersal events occurred from Australia to Euramerica with Hyneria lindae (to eastern North America) and E. wangsjoi (to Greenland/western Europe). The latter dispersal events, during the Famennian, are in agreement with the Great Devonian Interchange, which predicts dispersal events between Gondwana and Euramerica at this time.
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RBINS Staff Publications 2020