The argentiniform Surlykus longigracilis gen. et sp. nov., the most abundant fish from the Eocene Fur Formation of Denmark.

Paleontologists have identified and described Surlykus longigracilis, a new genus and species of argentiniform fish from the earliest Eocene Fur Formation in northern Denmark. This discovery sheds light on the evolutionary history of Argentiniformes, revealing that S. longigracilis occupies a basal position within this clade, serving as the sister-group to all other lineages. The fish's unique caudal skeleton, large mouth, and single supramaxilla distinguish it from other argentiniforms. Mass-mortality assemblages suggest that S. longigracilis formed large schools in the ancient North Sea Basin, likely playing a central role in the trophic structure of its ecosystem. This study provides significant insights into the biodiversity and paleoecology of the Eocene era.

Schrøder, A. E., Carnevale, G.,. (2023). The argentiniform Surlykus longigracilis gen. et sp. nov., the most abundant fish from the Eocene Fur Formation of Denmark. Bulletin of the Geological Society of Denmark, 72, 1–18. https://doi.org/10.37570/bgsd-2023-72-01