A new paleontological and evolutionary context for the diversity of the today’s European Gobiidae

• Applicant: Professorin Dr. Bettina Reichenbacher
• Subject Area: Palaeontology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 544460165

Members of the teleost suborder Gobioidei account for a significant component of the fish fauna in marine and freshwater habitats worldwide. In Europe, they are represented by two families, the Gobiidae and the Oxudercidae. The proposed project will focus on the European Gobiidae. The project objective is to elucidate the factors that drove the diversification of gobiid fishes across geological time. Three possible scenarios are proposed. The Burdigalian seaway hypothesis (H1) and the Climate optimum hypothesis (H2) both suggest that diversification of fossil and present-day gobiids occurred at the same time, and was triggered either by changes in the distribution of seaways during the Early Miocene (H1), or by the favorable climatic conditions in the Middle Miocene (H2). The Mediterranean re-flooding hypothesis (H3) postulates that ancient and present-day Gobiidae originated at different geological times. More specifically, it proposes that the latter evolved only around 5 Ma, when new ecological opportunities opened up as the Mediterranean Sea was re-flooded after the Messinian desiccation. To test these hypotheses, the goals of the project include: (i) significant improvement of taxonomic concepts for fossil species in order to obtain reliable data on the diversity of fossil species and genera, (ii) investigation of the relationships between fossil and modern gobiids, and (iii) time-calibration of the new phylogenies to evaluate which of the three hypotheses for the origin of the Gobiidae is most plausible. Three work packages (WP 1–3) are proposed, for which comparative material is already available in my lab. WP 1 will develop improved taxonomic concepts based on new actualistic data on the variability of morphological structures using MicroCT techniques. WP 2 involves extending our existing phylogenetic matrix (WP 2a) and otolith datasets (WP 2b) to perform new analyses; Implied weights-maximum parsimony and Bayesian inference will be used for skeleton-based fossils (WP 2a); Principal component and Cluster analyses are suitable for otolith-based fossils (WP 2b). WP 3 will conduct time-calibration of the new phylogenies in order to link temporal changes in species richness and genus and lineage diversity of the Gobiidae with climatic, palaeogeographic and palaeoenvironmental changes, which will eventually allow to evaluate which of the three hypotheses is most plausible. The proposed three work packages will make it possible to comprehensively interpret the evolution of a diverse and important group of freshwater and marine fishes in Europe, which also have a unique fossil record. The project will thus provide a completely new paleontological and evolutionary context for the diversity of today’s European Gobiidae.

• DFG Programme: Research Grants