Also known as gut or gizzard stones, gastroliths are common digestive aids among amphibians, reptiles, birds, and dinosaurs. their primary function is to help grind food matter.

In dinosaurs, gastroliths are usually associated with sauropods, though they have also been discovered in ornithomimids, oviraptors, and some ornithischians. This Jurassic period gastrolith comes from the Morrison Formation in Colorado.

There are two different sizes of gastrolith:

• Small: 1-2" (2.5-5cm)
• Large: 2" to 4" (5-10cm)

Above: Large (left) and Small (right) Gastroliths

The small size arrives inside a classic, glass-topped riker display case measuring 4 1/2" x 3 1/2". The large size ships without a case, in a sturdy carton. Both sizes include a small information card about the specimen.