Abstract Edrioasteroids from the Katian, Lower Ktaoua and Upper Tiouririne formations provide new data on several previously described species and two new species of edrioasteroids. Ontogenetic and palaeoecological data are provided for Moroccopyrgus matacarros . Well-preserved oral areas and internal views of the oral frame show Euryeschatia reboulorum to be an unusual lebetodiscinid rather than an isorophinid. The pyrgocystid Spinadiscus lefebvrei n. gen. and sp. and the highly inflated isorophinid Panidiscus tamiformis n. gen. and sp. are described. Specimens of Moroccopyrgus matacarros and Euryeschatia reboulorum are only found attached to echinosphaeritid rhombiferans and conulariids, respectively, suggesting commensal relationships. Other species attach to a variety of different surfaces.