Pustites

Pustites are a taxonomic genus of extinct trilobites belonging to the order Phacopida and the suborder Pterygometopidae. These fossils are found in Ordovician period rock formations, primarily in North America and Europe. Pustites are characterized by their distinctive glabella, the central raised lobe on the cephalon (head shield), which is typically inflated and ornamented with pustules or tubercles. The fixigenae, the fixed cheeks adjacent to the glabella, are often broad and slope downwards. The eyes of Pustites are generally large and prominent, as is common in many phacopids. Their thoracic segments are also often described as having a pustulose surface texture. The pygidium, or tail shield, is typically semicircular and possesses a segmented axis.

The ecological role of Pustites is inferred from their morphology and geological context. Like most trilobites, they are believed to have been benthic organisms, living on or in the seafloor. Their pustulose ornamentation may have served a defensive purpose, making them more difficult for predators to swallow, or it could have been related to camouflage or sensory functions. The specific environmental conditions in which Pustites lived, such as water depth and substrate type, can be inferred from the associated fossil assemblages found in their strata. The distribution of Pustites fossils provides valuable information for understanding paleogeography and the evolutionary history of trilobites during the Ordovician.