Morocco has been the scene of the discovery of new fossils of a prehistoric marine creature from 450 million years ago that has revealed new details about the evolution of the ancestors of modern crustaceans, insects and arthropods. The discovery, made by a team of researchers from the universities of Oxford (UK) and Yale (USA), has been published in the journal Nature .
This new species, named Aegirocassis benmoulae by its discoverer, Mohamed Ben Moula, lived about 480 million years ago during the Ordovician period in southeastern Morocco and is surprisingly a perfectly preserved fossil in three dimensions .
According to paleontologists, this specimen, which belongs to the anomalocarididae family (strange shrimp) reached a size of more than 2 meters in length but, despite its size, it fed exclusively by filtering plankton, revealing that in this form of life it did not there were only predators. “This discovery shows that during the Ordovician, planktonic aquatic ecosystems were already developed and complex , as they could feed such a large animal, in contrast to the earlier Cambrian period,” says Peter Van Roy, co-author of the study.
Thanks to this finding, paleontologists agree that it is the largest Animalocaris and possibly the last of its kind . On the head it has two spiny appendages that they used to grab their prey and a circular mouth surrounded by toothed plates. In addition, it presents two sets, two sets of fins on the body and not one as was believed until now.
On the other hand, the study of the fossils has revealed some filamentous structures in the back of the animal that experts believe were used for respiration: “we have shown that the upper set is equivalent to the hind limbs of arthropods, while the set The bottom corresponds to legs that are modified and adapted to swimming. This solves a previously problematic aspect of the anatomy of the anomalocaridos, because it demonstrates that the extremities of two bifurcations of the modern arthropods arose through the fusion of these two structures , confirming in turn that the anomalocaridos represent a very early stage in the evolution of arthropods ”, concludes Van Roy.
