Nature & Environment
Palaeobiology: The Riddle of the Stomach Stones
...the light air and act as ballast, stopping the animal floating to the surface. Hypothesis 3 - accidental ingestion Reptiles that feed on animals living on the sea floor (benthic animals) will accidentally swallow stones, gravel and sand as a consequence. In this case, gastroliths really have no function. Next: Find out what the evidence says... and reach your conclusion...