Holothuroidea - Apodida - Achistridae

Full reference: B. N. Fletcher. 1962. Some holothurian spicules from the Ampthill Clay of Melton, near Hull (Yorkshire). Geological Magazine 99(4):322-326

Belongs to Achistrum (Cancellrum) according to K. S. Soodan and R. Whatley 1987

Sister taxa: Achistrum beckmanni, Achistrum brevis, Achistrum brevis, Achistrum coloculum, Achistrum frizzelli, Achistrum gamma, Achistrum issleri, Achistrum longirostrum, Achistrum ludwigi, Achistrum monochordata, Achistrum multiperforatum, Achistrum nicholsoni, Achistrum permianum, Achistrum pulchrum, Achistrum triassicum, Achistrum tuto, Achistrum varicum, Achistrum (Achistrum) brownwoodensis, Achistrum (Cancellrum) bicordata, Achistrum (Cancellrum) pilgrimi, Achistrum (Cancellrum) meltonensis, Achistrum (Cancellrum) britanica, Achistrum (Cancellrum) warboysensis, Aduncrum cordatum

Type specimen: Holotype HU 14.j.1.3

Ecology: epifaunal detritivore