DINOSAUR BEHAVIOR
EATING HABITS
What did dinosaurs eat?
Based on the popular representations of dinosaurs in the media, these large, vicious creatures could eat anything they wanted and some probably did. In reality, there is very little direct evidence of what specific dinosaurs truly ate. But, based on rare evidence and other factors, paleontologists have made some assumptions about dinosaur diets.
Since dinosaurs lived on our planet for around 150 million years, they must have slowly adapted to the changing flora and fauna. Overall, there were apparently two major, and one minor, types of dinosaurs: herbivores, carnivores, and omnivores, respectively. Most of the dinosaurs were herbivores, or animals that ate available plants: the carnivorous dinosaurs, of course, ate animals, including other dinosaurs. Very few dinosaurs were omnivores animals that ate both meat and plants.
What food was available to the dinosaurs?
The food available to the dinosaurs gradually evolved over the millions of years of the Mesozoic era, just like the dinosaurs themselves. Most of the dinosaurs ate plants. Fossil evidence of pollen and spores indicates that there were hundreds to thousands of different types of plants growing during the Mesozoic era, most with edible leaves. Some examples of possible dinosaur delicacies included ferns, mosses, horsetail rushes, cycads, ginkos, and evergreen conifers like pine trees and redwoods (grass had not yet evolved). Toward the end of the Mesozoic era, with the advent of flowering plants, fruits also became available.
For dinosaurs of the carnivorous persuasion, there was also a large selection of food choices in the Mesozoic cafeteria. These included the early mammals, eggs, turtles, and lizards that shared the landscape with the dinosaurs. Of course, there were also other dinosaurs to be hunted or scavenged.
Did dinosaurs need water?
It is safe to assume that dinosaurs, like all living creatures, needed water to live. They probably obtained water much like modern reptiles, either directly from a water source; or from their food, such as the plants they ate (herbivores), the animals they consumed (carnivores), or both (omnivores).
What are coprolites?
Coprolites are the fossilized droppings, or feces, of dinosaurs. Because of the soft nature of this fecal material, dinosaur droppings would often disintegrate before they had a chance to fossilize. If they dropped in the wrong place, such as ocean shore where the waves would wash the material away, the chances of the dung becoming fossilized were almost nonexistent.
The shapes and sizes of most coprolites are not readily distinguishable between animals. Thus, there are, at present, few coprolites unequivocally traced back to dinosaurs, but the ones that have been identified offer tantalizing clues to dinosaur diets. In particular, such coprolites give us an insight into what the animal was eating, how it ate, and what happened later in terms of digestion.
The preservation and subsequent fossilization of coprolites depended on a number of factors, including the organic content and amount of water present in the deposited feces. It also included, of course, where the animal dropped the feces and the method of burial all keys to the formation of coprolites.
The feces of carnivorous dinosaurs were more likely to become fossilized than those of the herbivores because of their higher mineral content. These minerals were from bits of bone within the feces; in other words, from the consumption of other animals.
Are all coprolites large, especially those from the larger dinosaurs?
Not all coprolites are large. Individual coprolites can be small less than 3 inches (10 centimeters) long even though they came from a large dinosaur. A modern example of this phenomenon is the mule deer and elk of North America. These animals deposit many pellets that are less than a third of an inch (one centimeter) in size, even though these are relatively large animals.
In terms of dinosaurs, evidence for this phenomenon comes from a probable sauropod coprolite found in the Morrison formation of eastern Utah. Although this coprolite is about 16 inches (40 centimeters) in diameter, it is probably from a mass of smaller, individual pellets that merged together, probably because of a high water content.
Coprolites are actually fossilized dinosaur feces. Not a very glamorous subject for research, but paleontoligists actually discover a lot about what dinosaurs ate and more from these stones. This sample was from a young T rex. Discovered in Saskatchewan, Canada, it is about 17 inches (43 centimeters) long (U.S. Geological Survey).
