This was all very interesting although not earth-shattering from a scientific point of view, until a researcher, who specialized in insects, arrived on the site and started to carefully cut into the shale slabs. On one piece of material that was found the team noticed what seemed from a distance to be a tiny stain but which was shown to be a hexapod upon further analysis. It was an insect in other words. This may seem like nothing  at first glance but actually represents a major discovery. It is extremely rare to find such a complete fossil of an early insect. For although insects seem to have dominated animal biodiversity during the Carboniferous (geological period stretching roughly across a period of 350 to 300 million years), no complete fossil dating from the Devonian (the geological period before the Carboniferous) had ever been discovered. Not only had this fossil been discovered but it was in very good condition: insects are not usually well preserved due to the fact that they are fragile and lack internal skeletons.

However, this was not true of the insect found at Strud, which was soon nammed Strudiella devonica. Eight millimeters long, the arthropod had two long unforked antennae, external mandibles, a head with large round eyes, six legs, a body divided into three parts but has no wings.

A missing  part in order to understand the origin of insects

This discovery was revealed to be so exceptional that it caught the interest of the American journal Nature, which has just published an article devoted to Strudiella(1). Among the signatories, there are three researchers linked to the University of Liege: Julien Denayer, doctoral student and assistant lecturer, Sébastien Olive, doctoral student, both in the Animal and Human paleontology department directed by Professor Edouard Poty, and Cyrille Prestianni, paleobotanist and scientific collaborator at the University of Liege.

“ This fossil has all the basic characteristics of the insect group, it is a very interesting discovery because we still don’t know where they came from. This arthropod is therefore a proof that during the Late Devonian, insects were already well-developed, ” explain the three researchers. Consequently, insects have a much earlier origin than was previously imagined.

The researchers have even formulated a theory: if Strudiella devonica does not have wings, it may be because it is the larva of a winged insect, given that its mandibles are typical of those that we normally find in this category. This would seem to reinforce the idea that insects were already well installed on Earth 365 million years ago and that other species, even older, still remain to be discovered.

(1) http://www.nature.com/nature/journal/v488/n7409/full/nature11281.html