Asaphida

Asaphida is an extinct order of trilobites, a diverse group of marine arthropods that lived from the Cambrian to the Permian periods. Asaphid trilobites are characterized by their relatively simple and often large exoskeletons, typically lacking the elaborate spines or ornamentation seen in some other trilobite groups. Their glabella, the central raised lobe on the head shield, is usually broad and either indistinct or divided by shallow furrows. A notable feature of many asaphids is the presence of large, holochroal eyes, which are compound eyes made up of numerous small lenses.

Fossils of Asaphida are found in marine sedimentary rocks worldwide, indicating a widespread distribution across the ancient oceans. They are common in Ordovician and Silurian deposits. Asaphids occupied various ecological niches, with some likely being deposit feeders that sifted through sediment on the seafloor, while others may have been scavengers or even predators. Their size varied considerably, with some species reaching lengths of over 20 cm, making them among the largest trilobites. The taxonomic classification of Asaphida has undergone revisions over time, but it remains a significant and well-studied order within the trilobite fossil record. Their fossils provide valuable insights into the paleoecology and evolution of marine life during the Paleozoic Era.