Gastroliths - Stomach Stones

Gastroliths are stones and other hard objects which have formed in the stomach or which were swallowed and reside in the digestive tract. I am especially interested in swallowed stones which do occur commonly in fossil and living archosaurs (dinosaurs, crocodilians, and birds), and some other vertebrate groups such as tangasaurids, plesiosaurs, or pinnipeds. Today, herbivorous birds regularly use gastroliths (grit) to triturate foodstuff in their gizzard, the so called "gastric mill". Grit intake is commonly known from chicken, songbirds, and ratites. In dinosaurs, gastroliths have been reported in a number of taxa. To reveal the function of dinosaur gastroliths, I have conducted experiments with ostriches (Struthio camelus), the largest living bird species.

Gastroliths can help answering paleobiological questions such as composition of diet or reconstruction of migrational routes. In my PhD., I have focused on the function and distribution of gastroliths in sauropod dinosaurs. Currently, I am working on several gastrolith research projects, such as the identification of gastroliths (important because of finds of isolated pebbles which may have been used as gastroliths) or the function of gastroliths in aquatic vertebrates.


I am very interested in collaborations in gastrolith research. There are still so many open questions regarding stomach stones and there are just a few people worldwide working seriously on that topic. As far as I know, I am the only one who has spent several years entirely on this subject.