Phacops is one of the most recognizable trilobites of the Paleozoic, best known from the Devonian period (about 390 million years ago). Fossils are especially common in the Anti-Atlas Mountains of Morocco, where limestone beds preserve large numbers of these iconic arthropods. These rocks record the remains of once-thriving shallow seas that hosted a wide variety of marine life, with Phacops among the most abundant trilobites.

The most distinctive feature of Phacops is its pair of large, compound “schizochroal” eyes, composed of dozens of individually separated lenses that provided excellent vision on the seafloor. Careful preparation can reveal these eyes in beautiful detail, with each lens standing out clearly. Equally striking is the broad, well-defined glabella (the central lobe of the cephalon), which often preserves fine surface detail under skilled preparation, offering a vivid glimpse into trilobite anatomy.

Today, Phacops remains a favorite among collectors. When available, well prepared Moroccan examples like these are valued for their clear, lens-rich eyes and well-preserved cephalic features, making them excellent representative specimens of this classic Devonian trilobite.