Fossilized feces show evidence of occasional protein consumption among megaherbivores. As it turns out, plant-eating dinosaurs could have had a more diverse diet than previously thought.

On The Hunt For Fossilized Feces

Karen Chin, a paleontologist at the University of Colorado Boulder, has been studying fossilized feces of herbivorous dinosaurs for years. In 2007, Chin found chunks of rotting wood inside 74- to 80-million-year-old feces collected from the Two Medicine rock formation in Montana, suggesting that the herbivorous dinosaurs may have munched on the wood in their search for insects.

In 2013, she found similar feces in the Kaiparowits Formation of Grand Staircase-Escalante National Monument in southern Utah, except this time, along with the rotting wood were evidence of black, thin, convex structures. Under the microscope, the structures looked very much like crustacean legs or claws, something Rodney Feldmann of Kent State University confirmed.

Crustaceans In Herbivore Diet

One may not think highly of fossilized dinosaur droppings, but they do in fact pose significant finds. Compared to fossilized dinosaur bones, dinosaur feces often contain evidence for the kind of life and diet that the prehistoric giants had.

For instance, this particular finding shows that although large herbivores, as the classification suggests, mostly consumed plants, they do in fact consume crustaceans such as crabs or crayfish occasionally, perhaps to increase their calcium intake before laying eggs.

This finding is especially significant because carnivorous dinosaur feces are often more well-preserved compared to those of the plant-eaters because of the minerals in the bones of the animals they consume. Luckily in this case, the crustacean shells survived the test of time.

In Search Of Extra Protein

Seventy-five million years ago, the landscape where the fossilized feces were found was a wet land that likely resembles a subtropical environment. Chin believes that this is where local dinosaurs, the duck-billed hadrosaurs, likely went in search of sources of protein. In both of her findings, there is evidence of the herbivores consuming insects for protein. Now, it seems as though they might also have consumed crustaceans.

"You can't imagine a 20-foot hadrosaur going after a butterfly," said Chin.

However, another explanation could be that the megaherbivores might have just accidentally munched on the crustaceans, as believed by Jordan Mallon of Canadian Museum of Nature in Ottawa. Because of the sheer size of the creatures, Mallon believes that they may not have been too selective of the things that they eat otherwise they would have starved and died.

Regardless of the reasons why the megaherbivores consumed the crustaceans, even Mallon agrees that the findings provide excellent insight as to the kind of life that the giants lived.

The study was published in the journal Scientific Reports.