Did“Brontosaurus”;ever swim out to sea?: Evidence from brontosaur and other dinosaur footprints

Reevaluation of published information and discussion reveals serious shortcomings in the swimming‐sauropod interpretation proposed by Roland Bird in 1944. The most plausible alternative interpretation is that the tracks are underprint expressions of brontosaur trackways made during terrestrial progression. This circumstance indicates that thin beds of sediment ‘buoy up’ or support animals above underlayers just as effectively as several meters of water. Evidence supporting the underprint interpretation includes footprint depth and completeness, differential manus‐pes size (heteropody) in sauropods, trackway configurations, and the relationship between tracks and sedimentary structures, none of which has been considered in sufficient detail in previous studies. The underprint interpretation also lends support to the theory that brontosaurs were terrestrial and not aquatic in their adaptations, and shows how important it is to interpret footprint evidence with caution