I WONDER - Was The Stegosaurus A Herbivore?

Stiga sources were herbivores, primarily consuming leaves and grass. Due to their plant-based diet, they had few and small teeth, which were not sharp. To aid in digestion, they ingested small rocks to help crush and process the plant material in their stomachs.

What did the creatures use to help chew and crush their food?

Where would the creatures store the rocks used for chewing?