Stellispongiids have a solid skeleton (without chambers) encasing calcite spicules arranged in trabeculae (column-like structures).

[1][2] "Inozoans" and the similar "sphinctozoans" were historically grouped together in the polyphyletic order Pharetronida.

[2] Stellispongiids survived from the Permian to the Cenozoic, at least up to the Miocene Epoch.

[1] They comprised the majority of "inozoan" diversity in the Cretaceous Period, though their distribution was mostly restricted to Europe.

[2] The Treatise on Invertebrate Paleontology (2004) places the living sponge family Lelapiidae within Stellispongiida,[1] though Systema Porifera (2002) places Lelapiidae within the order Leucosolenida.