A carregar...
Projeto de investigação
Modeling the role of Iberia in the Mesozoic tetrapod paleobiogeography
Financiador
Autores
Publicações
Testing the Usefulness of the Surface Collecting Method in a Vertebrate Microfossil Site from the Barremian of Spain (Los Menires, Mirambel Formation)
Publication . Gasca, José M.; Parrilla-Bel, Jara; Moreno-Azanza, Miguel; Navarro-Lorbés, Pablo; Canudo, José I.; GeoBioTec - Geobiociências, Geoengenharias e Geotecnologias; DCT - Departamento de Ciências da Terra; MDPI - Multidisciplinary Digital Publishing Institute
Surface collecting is the first and sometimes the only type of sampling carried out in many fossiliferous localities, including vertebrate microfossil assemblages. Nevertheless, it is rare to test how representative these surface-collected samples are of the palaeobiocoenosis. A first approach to the palaeontological analysis of Los Menires, a Barremian vertebrate microfossil assemblage, is here performed while testing the usefulness of the surface collection method. New fossil material obtained by surface collection is described, and the resulting data are compared with those obtained by screen-washing. The fossil assemblage of Los Menires is dominated by parautochthonous remains of freshwater aquatic and semiaquatic organisms—i.e., charophytes, ostracods, bivalves, gastropods, testudinatans, crocodylomorphs, lissamphibians, and osteichthyans—although parautochthonous remains of terrestrial vertebrates—i.e., dinosaurs, lacertilians, and mammaliforms—are also present. The accumulation of vertebrate hard parts in Los Menires took place in a low-energy, shallow-water, depositional environment within the alluvial-lacustrine system represented by the Mirambel Formation. Sampling test results indicate that surface collection is effective in recognizing the main fossil groups present in an assemblage. Yet, it is not suitable for capturing delicate and tiny fossils nor for recognizing the abundance of eggshells. In contrast, it can generate an overrepresentation of other hard components such as coprolites or ornithopod teeth.
Large dinosaur egg accumulations and their significance for understanding nesting behaviour
Publication . Ezquerro, L.; Coimbra, R.; Bauluz, B.; Núñez-Lahuerta, C.; Román-Berdiel, T.; Moreno-Azanza, M.; GeoBioTec - Geobiociências, Geoengenharias e Geotecnologias; Faculdade de Ciências e Tecnologia (FCT); DCT - Departamento de Ciências da Terra; Elsevier BV
The accurate identification of dinosaur egg accumulations as nests or clutches is crucial for understanding the reproductive behaviour of these extinct species. However, existing methods often rely on the presence of complete eggs and embryo remains, and sedimentological criteria that are only applicable to well-structured sediments. In this study, we introduce an innovative approach to characterize egg accumulations in structureless sediments, where traditional nest structures may not be preserved. Our methodology employs a unique combination of sedimentological, taphonomic, geochemical, and geophysical proxies for the study of egg accumulations. We applied this approach to the egg accumulation from Paimogo (Jurassic, Portugal), traditionally interpreted as a nest. Our findings reveal that the Paimogo egg assemblage is a secondary deposit, resulting from a flooding event in a fluvial plain that dismantled several allosauroid and crocodylomorph clutches. The eggshell vapor conductance results, coupled with sedimentological evidence, suggest that allosauroid dinosaurs buried their eggs in the dry terrain of overbank areas close to a main channel during the breeding season, likely during the dry season to prevent the embryos from drowning. This research underscores the necessity of multidisciplinary approaches in interpreting egg accumulations and offers a novel methodology for studying these accumulations in structureless sediments. Our findings provide new insights into the breeding behaviour and nesting preferences of these extinct organisms, contributing to our understanding of dinosaur ecology.
A new ichthyosaur from the Lower Jurassic of Portugal (Iberian Peninsula)
Publication . Sousa, João Pratas E.; Roldão, Isabel Morais; Ríos, María; Puértolas-Pascual, Eduardo; GeoBioTec - Geobiociências, Geoengenharias e Geotecnologias; Faculdade de Ciências e Tecnologia (FCT); Institute of Paleobiology, Polish Academy of Sciences
Ichthyosaurs were a group of marine Mesozoic reptiles. Their presence in the Portuguese fossil record is scarce and ranges from the Sinemurian to the Toarcian. In this work we describe a new specimen—a nearly complete skull discovered in the Sinemurian of Praia de Água de Madeiros, São Pedro de Moel, Municipality of Marinha Grande (Portugal). This specimen represents the most complete and best preserved cranial remains from the Iberian Peninsula published to date. Phylogenetic analyses performed identified this specimen as a new genus and species, Gadusarus aqualigneus, the first to be identified in the Iberian Peninsula. The species is phylogenetically recovered as a baracromian ichthyosaur, part of the Neoichthyosauria and Parvipelvia clades.
Unidades organizacionais
Descrição
Palavras-chave
Contribuidores
Financiadores
Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
3599-PPCDT
Número da atribuição
PTDC/CTA-PAL/2217/2021