Cascolus

Cascolus is an extinct genus of stem-mandibulate known from the Coalbrookdale Formation.

Description
Cascolus is a long, somewhat vermiform arthropod, roughly 9 millimetres long. It has a head segment containing a head shield, stalked eyes and five pairs of limbs, the first similar to megacheirans and the other four biramous with gnathobases, followed by a nine-segmented thorax and two possibly limbless segments near the posterior. The trunk remains similar in size through tergites 1-4, and then decreases in width onwards into the limbless segments.

Ecology
Cascolus appears to have been a nektobenthic animal, possibly a scavenger.

Etymology
Cascolus was named in honour of Sir David Attenborough. The genus name derives from "castrum" ("stronghold") and "colus" ("dwelling in"), alluding to the Middle or Old English source for the name "Attenborough". The specific name ravitis derives from "Ratae" (the Roman name for Leicester), "vita" ("life") and "commeatis" ("messenger")

Distribution
Cascolus is known from a single specimen from the Silurian Coalbrookdale Formation in England, a diverse Silurian Lagerstatte.

Classification
Cascolus was originally considered as a stem-group phyllocarid. According to phylogenic analysis in Pulsipher et al. (2022), it is considered as stem-mandibulate instead.