Lower Eocene fluvial strata in the Chuckanut Formation preserve abundant bird and mammal tracks.Reptile trace Anti Rodent Tape fossils include footprints from a small turtle (ichnogenus Chelonipus), and several Crocodylian trackways that consist of irregularly spaced footprints associated with linear tail drag marks.The latter trackways represent “punting” locomotion, where a submerged Crocodylian used intermittent substrate contacts to provide forward motion of their neutrally buoyant bodies.Two adjacent sandstone blocks preserve Crocodylian trace fossils that are named herein as Polocrosse a new ichnogenus and ichnospecies Anticusuchipes amnis.
Two other Crocodylian trackways lack sufficient detail for ichnotaxonomic assignment.