The Nitty-Gritty Scoop on Dinosaur Poop

Does dinosaur poop carry important scientific information? Or is it just the butt of all dinosaur jokes? Read this article to find out!

You could say that the research I undertake for this blog can be called….excremental?

What a crappy joke, am I right?

I’ve written about some pretty… juvenile things for maxsblogosaurus, my personal favourite being the article about how the first name for a dinosaur in 1763 was “scrotum.” Yet nothing quite epitomizes crude humour more than poop talk, am I right? I certainly think so. So here we are, an article about dinosaur poop.

Could dinosaur dung fossilize? Of course! The fossilized turds, known as coprolites, were formed in similar fashion to other fossils, that is through mineralization after being rapidly buried(1). Minerals already found within the faeces would have assisted in this process, which may explain why carnivore coprolites are far more common than that of herbivores. It is important to note that dinosaur coprolites are very rare, since the source material decomposes very quickly, and that in order to for a fossil to be deemed a coprolite, some form of digested material must be present within. Despite this scarcity, coprolites are known from across the world in places like England, India, and the United States and represent a multitude of species.

Now that we know that dinosaur poop can fossilize, is there any point in studying it? Let’s start with the most basic reason: to see what dinosaurs were eating. While it is seemingly impossible to attribute a “floater” coprolite to a specific dinosaur (as it would be to attribute a turd on your front lawn to one of the neighborhood dogs,) paleontologists have actually managed to decipher identity in a few instances. On one occasion, a 47 cm long coprolite from the late Cretaceous Saskatchewan was identified as belonging to Tyrannosaurus due to it being the only large predator in the area. The fossil contained fragments of an ornithischian dinosaur, confirming that Tyrannosaurus was predatory….you know, in case the teeth didn’t make it clear. Another notable diet revealed by coprolites is that Maiasaura, a hadrosaurid from Montana, ate rotting conifer wood instead of living plants. This may have been done to ingest the proteins from insects found within, a fact that has been seemingly confirmed by the 2017 discovery of crustaceans within hadrosaur dung from Utah(2). While these dinosaurs were primarily vegetarians, it appeared they had a relatable craving for seafood, a fact that would have gone amiss if not for coprolites.

Coprolites do a lot more than just tell us what dinosaurs were eating. In the case of Tyrannosaurus, the presence of undigested bone fragments points to the remains having passed through the digestive system extremely quickly. This notion was confirmed by the discovery of an even bigger (65 cm!!) Tyrannosaurid poop from Alberta, a turd so well preserved that fossilized muscle tissue was visible! This remarkable discovery helped to prove that ingested food passed quickly through the digestive system of Tyrannosaurids, potentially signalling a high metabolism that was closer to that of a bird than to a crocodile. Or maybe the dinosaurs just had upset stomachs…

Coprolites can also tell us a lot about the animals living alongside dinosaurs too. Burrowing tunnels found within the coprolites of Maiasaura indicate the presence of dung beetles, small insects that either eat, or lay their eggs within, the faeces of larger animals. Dung Beetles still thrive in the present within the dung of animals like elephants, showing just how effective a life within stool can be, rather than the crappy existence you would expect it to be. Traces of other small animals, such as fly burrows and snail shells, have also been found within the dung of Maiasaura. Instead of being a barren wasteland, it would appear that dinosaur poop was actually a flourishing ecosystem for small insects of the Mesozoic.

Speaking of flourishing ecosystems, coprolites have helped show evidence of dinosaur parasites.  Analysis of Iguanodon coprolites has revealed the presence of three different kinds of parasites: Protozoans (single celled organisms), Trematodes (flatworms) and Nematodes (roundworms). The remains of the parasites were outstanding, with a multitude of eggs present and even a recently hatched nematode. Through the identification of parasitic species within coprolites, in addition to the dung beetles mentioned previously, coprolites have given us a glimpse not just into the ecosystems that depended on dinosaurs, but also the early evolution of creatures that survive into the present.

The recent discovery of a new beetle species in a dinosaur coprolite shows the untapped scientific potential of studying dinosaur coprolites. Using X-ray technology, paleontologists have revealed the new species to be one of unprecedented preservation. You’d think that after passing through a dinosaur digestive tract, it would be slightly damaged, but apparently not… Anyways, the coprolite has been theorized to have belonged to Silesaurus, an early dinosauriform that may give insight into the diet of the earliest dinosaurs. There is no direct correlation to this assessment, as Silesaurus is relatively rare at the site of discovery and lived alongside other insectivores. Nonetheless, the discovery of such a magnificent fossil shows the potential of new discovery that stems from the analysis of dinosaur poop.

Think that’s already a lot to digest? Well, there’s more. In what I imagine is a surprise, dinosaur poop has actually challenged the timeline of grass evolution. While the common notion is that grass didn’t exist during the time of the dinosaurs, fossils of sauropod coprolites from the late cretaceous of India have potentially proved otherwise. Analysis of two coprolite specimens revealed that the sauropods were eating similar foods to modern grazers, like buffalo, with one specimen outright containing grass residue within. With this discovery, it became clear that grass likely evolved sometime during the very end of the cretaceous period, some 70 million years ago, rather than after the dinosaurs as previously believed. Who would have thought that the very fabric of evolutionary history would be challenged by dinosaur poop?

I suppose that poop isn’t so juvenile after all. I mean, it was a coprolite that revealed the presence of grass during the time of the dinosaurs. Maybe we should all stop treating faeces as the butt of all potty humour. After all, the science of crap is far more expansive than what you would ever expect…

Works Cited

I do not take credit for any images found in this article

Header image found here

Tyrannosaurid coprolite courtesy of the Royal Tyrell Museum, found at their twitter here

Dung Beetle and Nodosaur courtesy of unknown, found here

New species of Beetle courtesy of the Ahlberg Research Lab, found here

  1. Martin, Anthony J. Dinosaurs without Bones: Dinosaur Lives Revealed by Their Trace Fossils. Pegasus, 2015.
  2. Witze, Alexandra. “Fossilized Poo Reveals How Vegetarian Dinosaurs Had a Taste for Crabs.” Nature News, Nature Publishing Group, 21 Sept. 2017,
  3. Kim, Shi En. “New Species of Beetle Found in 230-Million-Year-Old Feces.”, Smithsonian Institution, 30 June 2021,
  4. Prasad, Vandana, et al. “Dinosaur Coprolites and the Early Evolution of Grasses and Grazers.” Science, American Association for the Advancement of Science, 18 Nov. 2005,

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