Reconstructing paleotrophic relationships on the Brazilian Romualdo Formation (Lower Cretaceous) through mercury analysis in fossils
Silveira Antonietto, Lucas (Universidade Regional do Cariri. Museu de Paleontologia Plácido Cidade Nuvens)
Hamid, Igor (Universidade Federal do Ceará. Instituto de Ciências do Mar)
Holgado, Borja (Institut Català de Paleontologia Miquel Crusafont)
Leite Rocha, Antonio (Universidade Regional do Cariri. Centro de Ciências Biológicas e da Saúde)
Andréia Ferreira, Maria (Universidade Federal do Ceará. Instituto de Ciências do Mar)
Álamo Feitosa Saraiva, Antônio (Universidade Regional do Cariri. Centro de Ciências Biológicas e da Saúde)
Drude de Lacerda, Luiz (Universidade Federal do Ceará. Instituto de Ciências do Mar)
Costa da Silva, Rafael (Serviço Geológico do Brasil. Museu de Ciências da Terra)

Date:	2025
Abstract:	Mercury (Hg) biomagnification values tend to reflect relationships between species in the trophic web, where larger values indicate higher positions in the web. Herein, we present a pioneering attempt to reconstruct the paleotrophic linkages during the onset of the Romualdo Formation in the Araripe Basin (northeastern Brazil) based on analyses of the Hg concentrations ([Hg]) in fossil specimens recorded in this lithological unit. To understand these relationships, several vertebrate taxa were analyzed through cold vapor generation atomic absorption spectrometry (CV-AAS) to quantify [Hg] in both fossils ([Hg]Fossil) and their surrounding concretions ([Hg]Rock). The observed ratios (log[Hg]Sample) indicate greater biomagnification with changes in the feeding habits and sizes of the evaluated vertebrate taxa; the lowest values were observed in the small actinopterygian fish genera Rhacolepis and Tharrhias while the peak values were noted in large predators like Cladocyclus and Calamopleurus (apex species of the trophic pyramid). The feeding habits of Vinctifer were also reviewed, and the genus was reinterpreted from a filter feeder to a mesopredator; Neoproscinetes and an unidentified batoid ray (Chondrichthyes) were two durophagous bottom-feeding taxa that showed values compatible with their predicted feeding habits. Low values of the log[Hg]Sample ratios were observed in the ornithocheiraean pterosaurs (Reptilia), suggesting these were mesopredators specializing in smaller fish species, while Thalassodrominae presented intermediate-to-high log[Hg]Sample values, indicating their unique trophic role as terrestrial opportunistic generalists, ranging from predators to scavengers.
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Araripe Basin ; Geochemistry ; Mercury cycle ; Paleoecology ; Vertebrata
Published in:	Frontiers in earth science (Lausanne), Vol. 13 (July 2025) , art. 1551085, ISSN 2296-6463

DOI: 10.3389/feart.2025.1551085

10 p, 553.0 KB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Institut Català de Paleontologia Miquel Crusafont (ICP)
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