Paleontologists Find New Beetle Species in Coprolite of Triassic Dinosaur Relative

Friday, July 2, 2021

Contents of a coprolite fragment from the Krasiejów locality in Poland. Image credit: Qvarnström et al., doi: 10.1016/j.cub.2021.05.015.

By scanning a fossilized coprolite of Silesaurus opolensis, a dinosaur relative that lived 230 million years ago (Triassic period) in what is now Poland, paleontologists discovered a previously unknown species of ancient beetle.

“We didn’t know how insects looked in the Triassic period and now we have the chance,” said Dr. Martin Fikáček, an entomologist at National Sun Yat-sen University.

“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.”

“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,” added Dr. Martin Qvarnström, a paleontologist at Uppsala University.

“This is facilitated by coprolites’ calcium phosphatic composition. This together with early mineralization by bacteria likely helped to preserve these delicate fossils.”

In the new research, Dr. Fikáček, Dr. Qvarnström and their colleagues examined a fragmentary coprolite from the Upper Triassic beds of the Krasiejów locality in Poland.

They scanned the specimen using synchrotron microtomography, a method that visualizes internal structures in fossils in 3D with great contrast and resolution,

“So if you find an insect in the coprolite, you can scan it using microCT in the same way as we do with amber insects, and you can see all the tiny details of the insect body as we do in amber,” Dr. Fikáček said.

“In that aspect, our discovery is very promising, it basically tells people: Hey, check more coprolites using microCT, there is a good chance to find insects in it, and if you find it, it can be really nicely preserved.”

The researchers named the new beetle species Triamyxa coprolithica, which refers to its Triassic age and indicating that it belongs to the suborder Myxophaga – and the newly-established myxophagan family Triamyxidae — and that it was found in a coprolite.

The beetle likely lived in semiaquatic or humid environments and was likely consumed by Silesaurus opolensis.

“Although Silesaurus opolensis appears to have ingested numerous individuals of Triamyxa coprolithica, the beetle was likely too small to have been the only targeted prey,” Dr. Qvarnström said.

“Instead, Triamyxa coprolithica likely shared its habitat with larger beetles, which are represented by disarticulated remains in the coprolites, and other prey, which never ended up in the coprolites in a recognizable shape.”

“So it seems likely that Silesaurus opolensis was omnivorous, and that a part of its diet was comprised of insects.”

The team’s paper was published in the journal Current Biology.


Martin Qvarnström et al. Exceptionally preserved beetles in a Triassic coprolite of putative dinosauriform origin. Current Biology, published online June 30, 2021; doi: 10.1016/j.cub.2021.05.015