Published online by Cambridge University Press: 20 May 2016
Disarticulated spines and sclerites of assumed multiple row problematic organisms are present in several Mississippian and Pennsylvanian stratigraphic units. Marginal spines and dorsal spinose sclerites are present. Marginal sclerites are distinguishable into anterior, posterior, and left- and right-handed lateral forms. The new family Aenigmatectidae and genus Aenigmatectus with two new species, A. hystricosus and A. magnacavus, are recognized. Aenigmatectus sp. from the Mississippian is also described. The family is tentatively assigned to the order Hercolepadida Dzik, 1986.