Scientists have discovered a 230-million-year-old species of beetle perfectly preserved in fossilized manure. The species represents a new family of beetles and probably served as a snack for a dinosaur ancestor in the Triassic period.
The discovery highlights how fossilized manure, called coprolite, can open a window to the past. From Giving scientists a look In ancient gut bacteria communities, to share secrets about parasites in animals, petrified poop has already proven to be an important research tool.
“We didn’t know what insects looked like in the Triassic period and now we have the opportunity,” said Martin Fikáček, an entomologist at National Sun Yat-sen University in Taiwan and a co-author of the article published on wednesday in the journal Current Biology.
As more coprolites are analyzed, scientists may find that some harbor well-preserved insects, Fikáček added.
Amber, which is fossilized tree resin, has encapsulated insects dating back 140 million years. This batch of manure allows scientists to see even more in the past.
Fikáček and the research team glimpsed the inside of the fossil poop using a method called synchrotron microtomography, which works like a hospital CT scanner but with strong X-ray beams. The technique allows visualizing internal structures in 3D in fossils with high resolution and contrast.
The researchers found the beetles with their legs and antenna intact. Scientists say that the chemical composition of the coprolites, along with early mineralization by bacteria, likely helped preserve the creatures.
“I was very surprised to see how well preserved the beetles were,” said paper co-author Martin Qvarnström, a paleontologist at Uppsala University in Sweden. “When you modeled them on the screen, it was like they were looking directly at you.”
Scientists named the species Triamyxa coprolithica, in reference to its Triassic age, beetle suborder, and its discovery in coprolite. Modern representatives of the Triamyxa beetle suborder, Myxophaga, are small and live on algae in moist environments.
In its day, Triamyxa probably lived in semi-aquatic or humid environments. The beetles were likely ingested and expelled by Silesaurus opolensis, a beaked dinosaur ancestor that was about 6.5 feet (2 meters) long and lived at the same time as the beetle in what is now Poland.
Silesaurids, which includes Silesaurus opolensis, are one of the closest relatives of Dinosauria. Lacking the shared derived features expected in the more recent common ancestor of Iguanodon, Diplodocus, and Megalosaurus and their descendants, the Silesaurids do not appear to be true dinosaurs, according to the University of Maryland. The Silesaurus in question appears to have chewed up several Triamyxa individuals, but scientists say the beetle was probably too small to be the sole target of the dinosaur ancestor.
“Triamyxa probably 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 way,” Qvarnström said. “So it seems likely that Silesaurus was an omnivore and that part of its diet was made up of insects.”
Whether it’s the little beetle that Silesaurus found particularly delicious, or something else, it’s good that he left us a remnant of his lunch, a rare portal to insect fauna millions of years ago.
The erection of a spider and other interesting things trapped in amber
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