Digging Through Poop, Scientists Discover 230-Million-Year-Old Beetle Species

A 230-million-year-old beetle has become the first species to have been identified and described after being trapped in the fossilized poop of a dinosaur ancestor.

Scientists made the discovery after examining the fossilized feces, also known as coprolites, attributed to a close dinosaur relative from the Triassic period. The beetle species, named Triamyxa coprolithica by the scientists, represents a new family of insects, previously unknown to science. according to the study published in the journal Current Biology.

The beetles were preserved in a 3D state: All of their legs and antennae were fully intact, which is incredibly remarkable.

"I was really amazed to see how well preserved the beetles were, when you modeled them up on the screen, it was like they were looking right at you," said first author Martin Qvarnström, a paleontologist at Uppsala University, Sweden, in a statement. "This is facilitated by coprolites' calcium phosphatic composition. This together with early mineralization by bacteria likely helped to preserve these delicate fossils."

The study is extremely exciting since it delves into a relatively new area of paleontology. While coprolites can be found in museum and research collections in abundance, few scientists have examined them for their content since most didn't think tiny insects could successfully pass through a digestive system and still be in a recognizable form. Insects trapped in amber, or fossilized tree resin, are the source of knowledge for many paleontologists, telling us about their evolution; however, these fossils aren’t particularly old, with the oldest ones going back to around 140 million years ago. This makes the discovery of a 230-million-year-old new species pristinely preserved in fossilized droppings even more astounding.  

"We didn't know how insects looked in the Triassic period and now we have the chance," said co-author Martin Fikáček, an entomologist at National Sun Yat-sen University, Taiwan. "Maybe, when many more coprolites are analyzed, we will find that some groups of reptiles produced coprolites that are not really useful, while others have coprolites full of nicely preserved insects that we can study. We simply need to start looking inside coprolites to get at least some idea."

Scientists were able to visualize internal structures in the coprolite in three dimensions with great contrast and resolution by scanning it with synchrotron microtomography at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France.

The team named the newly discovered beetle species Triamyxa coprolithica, which roughly translates to "beetle poo stone," saying that it likely lived in semiaquatic or humid environments. This discovery not only reveals the new beetle species, but also offers crucial knowledge on the diets and environments of the animals that ate them.  It was likely eaten by Silesaurus opolensis -- a beaked dinosaur ancestor that lived in what is now Poland and likely produced the poop.

"There are heaps of things you can study based on fossilized droppings but it had been hard to understand what to do with it, hard to recognize what is inside, and hard to draw conclusions from it, but now there are tons of data," added Qvarnström. "The ultimate goal is to use the coprolite data to reconstruct ancient food webs and see how they changed across time."