Gastrolith

A stomach stone swallowed by an animal and polished in the gut; genuine ones are found inside a skeleton's rib cage, and loose polished pebbles sold as gastroliths cannot be verified as such.

Sources

Treatise on Invertebrate Paleontology — glossaries (KU Paleontological Institute, CC BY 4.0)
Earle, S. (2019). Physical Geology, 2nd ed., Chapter 8: Fossils (CC BY 4.0)

Cite this article

Stratum Study. "Gastrolith" (Glossary). Stratum Study pack 2026.09, as of 2026-09-16. https://stratum.black/study/glossary/gastrolith. Accessed 2026-09-20.

BibTeX · CSL-JSON

@misc{stratum-gastrolith,
  title        = {Gastrolith},
  author       = {{Stratum Study}},
  howpublished = {\url{https://stratum.black/study/glossary/gastrolith}},
  year         = {2026},
  note         = {Glossary article, Stratum Study pack 2026.09, as of 2026-09-16; sources: stratum. Accessed 2026-09-20.}
}

Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.