Holothuroidea - Apodida - Achistridae

Alternative combinations: Achistrum (Achistrum) ludwigi, Ancistrum ludwigi

Full reference: C. Croneis and J. McCormack. 1932. Fossil Holothuroidea. Journal of Paleontology 6(2):111-148

Belongs to Achistrum according to K. Zawidzka 1971

Sister taxa: Achistrum beckmanni, Achistrum brevis, Achistrum brevis, Achistrum coloculum, Achistrum frizzelli, Achistrum gamma, Achistrum issleri, Achistrum longirostrum, 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, Achistrum (Cancellrum) trichordata, Aduncrum cordatum

Type specimen: Its type locality is Claypit, Bridgeport, Wise County, which is in a Missourian marine claystone in the Graford Formation of Texas

Ecology: epifaunal detritivore