The ones that got away: anatomy and evolution of exceptional early teleost fish fossils

The staggeringly diverse and abundant teleost fishes account for 99% of the 36,000 living species of ray-finned fishes. Despite an abundance of exceptional three-dimensional fossils, our understanding of the anatomy and relationships of the early members of this group is poorly constrained. Early teleosts are both taxonomically and morphologically diverse, and their anatomically complex skulls and braincases have the potential to resolve outstanding questions. Propagation phase contrast synchrotron X-ray µCT of key early teleost specimens provides an unrivalled opportunity to peer inside the heads of these fossils. By revealing new and detailed anatomical information, questions of phylogenetic affinity and morphological innovation leading to the extant teleost radiation can be confronted. Once a robust hypothesis of phylogenetic relationships has been established, macroevolutionary patterns relating to teleost evolution, diversification, and extinction pressures can be investigated.