Paläontologisches Institut und Museum

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Prof. Dr. Marcelo Sánchez
Pattern and process in evolutionary radiations of ray-finned fishes
Leadership/contacts
Duration
September 2011 to March 2018
Funding sources
SNF (Personen- und Projektförderung)
Sinergia
Collaborations
Walter Salzburger (Universität Basel) (Switzerland)
Regions
world map
Summary
Palaeontologists approach evolutionary questions primarily via the study of overall patterns of diversity changes at higher taxonomic levels and along a geological time axis. Biologists, on the other hand, concentrate largely on population and species-level approaches during much shorter time spans. Yet, if a comprehensive understanding of the processes governing the generation of biological diversity is to be achieved, then an integration of the two approaches is essential. This liaison is, unfortunately, diminished by e.g. biases of preservation in the fossil record, limited communication among disciplines, and the lack of case studies with appropriate phylogenetic and ecological frameworks. In this project, these difficulties are overcome with the availability of a unique collection of palaeontological population samples (in a controlled stratigraphical and palaeoecological context and consisting of hundreds of fossil specimens resembling an extinct species flock) and the access to three extant evolutionary radiations. Subject of our surveys are ray-finned fishes. As members of the largest clade of living vertebrates, they represent an appropriate model to examine the origin of biodiversity. We apply a diverse set of methods to quantify – in the fossil and the living models in parallel – the interplay between morphological differentiation and taxonomic diversification in an ecological context. The fossil group to be investigated is Saurichthys, a Triassic genus with three fundamental features: (i) a worldwide distribution at a critical geological time in view of global extinction and biodiversity recovery events, and (ii) a fine-scaled stratigraphical record of large populations preserving individual growth data in (iii) contemporaneous basins, in which palaeoecology can be assessed. The palaeontological data are the starting point for comparative analyses, using the same suite of methods, in three extant species flocks: the cichlid assemblage of Lake Tanganyika in East Africa, the notothenioids of the Antarctic waters, and the sticklebacks of the temperate zone. The study of growth trajectory data in fossils and in extant taxa will provide valuable information on the developmental mechanisms behind the diversification patterns. The integration of approaches on exceptional materials should result in the establishment of new model cases to study evolutionary diversification events in the largest clade of vertebrate animals.
Publications
Argyriou T, Clauss M, Maxwell EE, Furrer H, Sánchez-Villagra MR. Exceptional preservation reveals the gastrointestinal anatomy of a triassic ray-fin (Saurichthys) – on the evolution of the spiral valves of fishes. Scientific Reports. (in press)
Wilson LAB, Colombo M, Sánchez-Villagra MR, Salzburger W (2015) Evolution of opercle shape in cichlid fishes from Lake Tanganyika - adaptive trait interactions in extant and extinct species flocks. Scientific reports 5: 16909
Scheyer TM, Schmid L, Furrer H, Sánchez-Villagra MR. 2014. An assessment of age determination in fossil fish: the case of the opercula in the Mesozoic actinopterygian Saurichthys. Swiss Journal of Palaeontology 133(2):243-257.
Maxwell E, Furrer H, Sánchez-Villagra MR. 2013. Exceptional fossil preservation demonstrates a new mode of axial skeleton elongation in basal ray-finned fishes. Nature Communications doi:10.1038/ncomms3570
Maxwell E, Wilson LAB 2013. Regionalization of the axial skeleton in the ‘ambush predator’ guild – are there developmental rules underlying body shape evolution in ray-finned fishes? BMC Evolutionary Biology 13:265.
Aguilera O, Lundberg J, Birindelli J, Sabaj Pérez M, Jaramillo C, Sánchez-Villagra MR (2013) Palaeontological evidence for the last temporal occurrence of the ancient western Amazonian river inflow into the Caribbean. PloS ONE 8(9): e76202
Wilson LAB, Colombo M, Salzburger W, Sánchez-Villagra MR. 2013. The evolution of opercular bone shape in Antarctic icefishes – a study of morphological disparity in an adaptive radiation. Ecology and Evolution 3:3166–3182.
Wilson LAB, Furrer H, Stocker R, Sánchez-Villagra MR. 2013. A quantitative evaluation of evolutionary patterns in opercle bone shape in Saurichthys (Actinopterygii: Saurichthyidae). Palaeontology 56:901-915.
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