Herbivorous, house-sized dinosaurs like Apatosaurus and Brachiosaurus had to eat hundreds of pounds of plants and leaves every day to maintain their weight--so as you can imagine, there was a lot of dinosaur poop littering the ground in Jurassic times. However, unless a giant blob of Diplodocus doo happened to fall on the head of a nearby critter, he was unlikely to complain, since dinosaur feces were an abundant source of nutrition for smaller animals (not to mention bacteria).
Dinosaur droppings were also crucial for ancient plant life. Just as modern-day farmers scatter manure around their crops (which replenishes the nitrogen compounds that make soil fertile), the millions of tons of dinosaur dung produced every single day in the Triassic, Jurassic and Cretaceous periods kept the forests lush and green. This, in turn, helped to maintain the vegetation the dinosaurs feasted on, and then turned into poop, and so on and on in an endless symbiotic cycle. (See also Could Dinosaurs Fart?)
Dinosaur Poop and Paleontology
As important as they were for the primitive ecosystem, dinosaur droppings have proved equally crucial for modern-day scientists. Occasionally, archaeologists stumble across huge, well-preserved pieces of fossilized dinosaur dung—or “coprolites,” as they’re politely called. By examining these fossils in detail, researchers can figure out if they were created by plant-eating, meat-eating, or omnivorous dinosaurs—and they can sometimes even identify the type of animal or plant that the dinosaur ate a few hours (or a few days) before going Number 2.
Every now and then, a coprolite can help to settle evolutionary disputes. For example, coprolites unearthed recently in India show that the dinosaur responsible fed on types of grass that weren’t thought to have evolved until much later. By pushing back the flourishing of these grasses from 55 million years ago to 65 million years ago (give or take a few million years), these coprolites may help explain the evolution of megafauna mammals called gondwanatheres, which had teeth adapted for grazing.
The King of Coprolites
One of the most famous of all coprolites was discovered in Saskatchewan, Canada, in 1998. This gigantic poop fossil (which looks pretty much the way you’d expect) is 17 inches long and 6 inches thick, and was probably part of an even larger chunk of dinosaur dung. Because this coprolite is so big--and contains fragments of bone and blood vessels--archeologists believe it may have come from a carnivorous Tyrannosaurus Rex that roamed North America about 60 million years ago. For most coprolites, though, the exact identities of the dinosaurs that produced them will remain forever a mystery.