Biologist Martin Qvanström of Uppsala University in Sweden and his colleagues were studying 230-million-year-old coprolites or fossilized droppings when they discovered something unusual: a large number of beetle fragments preserved in the dung.
The researches named the newly discovered beetle species Triamyxa coprolithica. Qvanström surmised that it was probably semiaquatic with a convex body shape, saying "Boat shaped almost. Very small and cute."
From New Scientist:
“To get fossilised remains of this quality, researchers have relied in the past on finding them in amber (fossilised tree resin),” says Jesus Lozano-Fernandez at the Institute of Evolutionary Biology in Barcelona, Spain. “The novelty here is the possibility of looking at what is inside of the opaque fossilised poo.”
The earliest amber deposits formed about 140 million years ago early in the Cretaceous period, meaning we can’t rely on amber to learn about beetle evolution before that.
These coprolites allow us to learn about this and ecological relationships in an earlier period called the Triassic.
The droppings containing T. coprolithica probably came from Silesaurus opolensis, a reptilian dinosaur relative which ate these beetles in large numbers.