An article published in the journal “Scientific Reports” reports a study on the eyes of the trilobites of the Geesops schlotheimi species, which lived about 390 million years ago. A team of researchers led by zoologist Brigitte Schoenemann examined fossils of this trilobite and old X-ray images of fossils to study its eyes. The structure of those eyes is peculiar even among trilobites and exists only in the order Phacopida: it features a small number of relatively large, well-separated, lenses, each covered by its own cornea. It’s a sophisticated structure that perhaps was useful for seeing in low light.