- Cenozoic mammals - Canis Dirus
- Geologic time scale
- Sketch of a gastrolith—the gizzard stone of an ancient reptile
These highly polished well-rounded stones (gastrolith) are believed to have been used in the stomachs of reptiles for grinding the food into smaller pieces. Large numbers of these “stomach stones” have been found with the remains of certain types of dinosaurs. - Sketch of a coprolite—fossilized animal excrement
Coprolites are fossil dung or body waste. These objects can provide valuable information as to the food habits or anatomical structure of the animal that made them.