How did insects appear on Earth ? The question remains a mystery to this day. A discovery made in Strud in the province of Namur (Belgium), could provide the key to unlocking the secrets of these little animals. A team of researchers (including from the University of Liege)  have discovered the oldest complete fossil insect  ever found. Called Strudiella devonica, it lived no less than 365 million years ago. In spite of its great age, it is remarkably well preserved.

It all started with another no less important fossil, which had remained dormant in the collections of the University of Liege for a very long time, since the end of the 19th century to be exact. At this time, the geologist Maximin Lohest (who, anecdotally, also discovered the bones of the “ Man of Spy ” with the help of  prehistory expert Marcel Du Puydt) had placed it there. The paleontologist was convinced: this fossil could only be the mandible of a fish (seven centimeters long), dating from the Upper Famennian. However, he did not carry his analysis any further and the discovery remained in the collections of the University of Liege among other discarded fossils.

This all changed when a young paleontologist from the Natural History Museum of Paris, Gaël Clément, spotted a drawing of this fossil in an old publication. For him, something was not quite right : the orientation of the teeth, the jaw…nothing seemed to truly resemble the mandible of a fish. He arrived in Liege, studied this piece of sandstone closer and found the laconic inscription  “ Strud ” on it.  

It took few time before this name became associated with a small quarry located in a village of the municipality of  Gesves, in the province of Namur in Belgium. The team of researchers from Belgium, armed with the new geological map of Wallonia found the exact location of the quarry where the mandible was found. This was a “ hole ” around four meters wide and fifteen meters long which was examined with a fine-tooth comb.

In 2003, Gaël Clément confirmed his earlier intuition: the fossil was not that of a fish but was in fact that of a tetrapod, Ichthyostega. This discovery caused quite a stir at the time but that’s another story.

And then there were arthropods

Since then, research in the former quarry in Strud has not stopped. Under the aegis of the Natural History Museum of Paris, the Royal Institute of Natural Science of Brussels and the University of Liege, a team comes here twice a year and continues to probe the rock over a ten-day period. The rock appears to be very rich. The river that ran through the area more than 365 million years ago (which is today completely full of sediment) left a lot of traces. Fossils - sometimes well preserved - of crustaceans, plants and vertebrates…