Two skeletons of the newly described Early Cretaceous ornithopod dinosaur Changmiania liaoningensis were found in a burrow that was buried by a volcanic eruption about 150 million years ago in China.
There is a great photo from the Peerj article of gastroliths found clustered inside the skeleton. We should show this photo to all members that show us purported gastroliths as an example of the level of proof need to prove that their stone is a gastrolith.
Yang Y, Wu W, Dieudonné P, Godefroit P.2020. A new basal ornithopod dinosaur from the Lower Cretaceous of China. PeerJ8:e9832 https://doi.org/10.7717/peerj.9832