Some 230 million years ago, on a day like any other, a specimen of Silesaurus opolensis, a reptile ancestor of dinosaurs, was eating a large amount of green algae and subsequently defecated. Now, a team of scientists from Sweden, Taiwan, Germany and Mexico have discovered in these fossilized feces an entire family of undigested beetles; a completely new species to science.
Despite the fact that amber is one of the best materials that exist to preserve insects and small creatures, fossilized feces have nothing to envy. In this case, it looks like there were beetles on the menu .
The researchers used synchrotron microtomography to scan a 230-million-year-old coprolite – fossil feces – and found that it was filled with different parts of a beetle’s body. Some of them were even complete, with legs and antennae, which allowed scientists to analyze, compare and describe them. In doing so, they discovered that the beetles constituted a new species, an extinct lineage of the suborder Myxophaga . Its relatives still live today, mainly around algae.
The Triassic is a crucial period for the evolution of insects, especially for beetles, which are the most diverse order of organisms on Earth today.
It is believed that the samples were probably so well preserved thanks to the calcium phosphate composition of the coprolites and the early mineralization facilitated by bacteria in the stool. The researchers suspect that the coprolite in question belonged to Silesaurus opolensis, a Triassic dinosaur ancestor that was about 2 meters long. Although the droppings contained many beetles, they were likely bycatch, as S. opolensis was reveling in something more substantial, as its diet was mostly plants. Although it is seen that he also had a predilection for insects, given the number of beetles found in his excrement. Something like a nutritional supplement to food.
The team believes that the tiny beetles, which were about 0.10 centimeters long, were found in moist or semi-aquatic environments.
“We did not know what insects looked like in the Triassic period and now we have the opportunity to see it,” says entomologist Martin Fikáček of National Sun Yat-sen University, Taiwan and co-author of the work published in the journal Current Biology.
The discovery that insects can be preserved so well in coprolites offers a new window for studying ancient insects alongside amber, the fossilized tree resin that typically produces the best quality specimens. Additionally, fossilized feces are fairly common finds at paleontological excavation sites and have another silver lining: coprolites appear further back than amber in the fossil record, allowing paleontologists to study the evolution of insects much further back. in the past.
Referencia: Exceptionally preserved beetles in a Triassic coprolite of putative dinosauriform origin Martin Qvarnström Martin FikáčekJoel Vikberg WernströmEmmanuel Arriaga-VarelaPer E. AhlbergGrzegorz Niedźwiedzki Open Access Published:June 30, 2021 DOI: https://doi.org/10.1016/j.cub.2021.05.015
