Cheirurus

Cheirurus is an extinct genus of trilobites, a group of marine arthropods that lived from the Cambrian to the end of the Permian period. Fossils of Cheirurus are found in marine sedimentary rocks, primarily dating to the Silurian and Devonian periods. The genus is characterized by its distinctive glabella, the central raised portion of the cephalon (head shield), which is usually segmented and often bulbous. The pygidium, or tail shield, is also typically well-developed and may bear spines. Cheirurus possessed prominent genal spines, extensions of the cheek. These trilobites were likely benthic, living on or near the seafloor. Their exact diet is debated, but many trilobites are thought to have been scavengers or detritivores. The genus Cheirurus is important in biostratigraphy, meaning its presence and specific features can help date rock layers. Numerous species have been described within the genus, reflecting a wide distribution across ancient seas. Like other trilobites, Cheirurus underwent molting throughout its life cycle. The fossil record provides insights into their anatomy and evolutionary relationships within the order Lichida.