PhD: Specimen-level phylogeny in extinct and extant vertebrates

Specimen-level phylogenetic analysis based on osteology is becoming increasingly popular in vertebrate palaeontology. This kind of phylogenetic analysis includes single specimens instead of species or genera as operational taxonomic units, and thus ignores earlier taxonomic identifications based on morphological comparative studies. It is widely used in molecular phylogenetic studies, but rarely by morphologists. Specimen-level phylogenetic analyses can be considered a bottom-up approach to reassess the referral of a particular specimen to a species, and has indeed predominantly been used for taxonomic and systematic purposes. Whereas these issues are certainly important, the potential of these studies is much larger. A specimen-level phylogenetic analysis not only provides information about relationships between individuals, but also on the importance and variability of certain traits in the evolution of the taxon under study. When correlated with a well-dated stratigraphy, first occurrences of diagnostic traits can theoretically be pinpointed to a particular time and place. Further correlations with paleoclimatic, paleoenvironmental, or molecular data can then yield information on evolution in preeminent detail. Morphological phylogenetic matrices are prone to particular difficulties for cladistic analysis, however. Paleontological data sets in particular present a number of methodological challenges that researchers have to cope with when setting up a specimen-level phylogenetic analysis. The proposed project aims to evaluate different methodological approaches in various vertebrate clades of both extinct and extant taxa. It will provide crucial information on what kind of analysis is most accurate in which taxon, yield new data on character evolution across vertebrates through time, and allow to compare evolutionary rates across clades.