Amber preserves beetles that ate dinosaur feathers 105 million years ago | Sciences

A new fossil preserved in amber reveals that, 105 million years ago, there were beetles feeding on dinosaur feathers. The rare find provides a clear example of the interaction between vertebrates and arthropods during the Cretaceous period and is described in an article published in the April issue of the journal Proceedings of the National Academy of Sciences (PNAS).

Found in the municipality of San Justo Desfern in northeastern Spain, amber features tiny beetle larvae encircling downy feathers dating back 105 million years. This feathered one belonged to a theropod dinosaur that has no known species yet, but that lived in the Lower Cretaceous period. It is known that feathers do not belong to modern birds because these animals did not appear until the late Cretaceous period, 30 million years after the age of the fossil record.

The identified larvae appear to be related to modern beetles of the family Dermestidae, which are known to attack poorly stored produce and dry museum collections, especially organic matter that is difficult for other animals to digest, such as natural fibers. They can also be seen in the nests of birds and mammals, where they accumulate feathers and fur.

It is in such an environment that researchers believe that the remains of the Cretaceous period were found. Signs of decomposition (which include filaments of fungus) on the feathers that were found indicate that they separated from the dinosaur host. As far as the caterpillars are concerned, it is likely that they lived in the theropod itself or in its nest – and this would be close to the resin-producing tree that would preserve the fossil found in Spanish soil.

“It is unclear whether the feathered theropod host would have benefited from beetle larvae feeding on their separate feathers in this plausible nest scenario,” he says, in the current situationRicardo Perez de la Fuente of the Oxford University Museum of Natural History (OUMNH) and co-lead author of the study.

“However, the theropods may not have been harmed by the larval activity, as our data indicates that they did not feed on ‘live’ feathers,” he adds. “In addition, the larvae lacked defensive bristle-like structures, which can irritate the skin of their nest hosts, It even kills her.”

Vertebrates and arthropods have coexisted for at least 500 million years and their relationships have decisively shaped the evolutionary history of animals. However, evidence of these interactions is extremely scarce in the fossil record. Most of the preserved depict parasitism relationships, but this study indicates that the larvae found in Spanish amber did not harm the dinosaur host–and may even have benefited from it.

What is known is that it is possible that this relationship between dermestids and feathered animals outlived the dinosaurs and can be observed even today. “An emerging view is that some groups of arthropod symbionts of feathered theropods in the late Mesozoic Era switched to modern birds in the Cenozoic, Earth’s current geological age,” explains Perez de la Fuente.