Known as gastroliths, the pieces of pink quartzite have revealed that long-necked sauropods most likely swallowed them (maybe to grind the tough plant matter they ate) as they migrated to their own Great Valley.
“We interpret that these gastroliths were ingested by dinosaurs, most likely sauropods, in the Laurentian midcontinent and then transported in their digestive tracts to the site of deposition,” said Joshua Malone, a grad student at the Jackson school of Geosciences at the University of Texas at Austin, who recently led a study published in
Terra.
Before Wyoming or Wisconsin or humans were ever a thing, what is now North America and parts of Europe made up the paleocontinent of Laurentia. This was where many of Little Foot’s relatives roamed. The Baraboo Quartzite, where they are thought to have started their journey to the region that would end up being Wyoming, is much older than any dinosaur — which could have made it seem as if dinos traveled backwards through time if it wasn’t for modern technology.