This page represents the following TreeOfLife-200M taxonomic path.[1]
Acarnus innominatus is known from preserved museum material; available images from online collections show specimens preserved as sponge fragments/sections (museum invertebrate zoology holdings) that are consistent in overall form with encrusting to low-relief sponge morphologies typical of many Poecilosclerida (species-level external characters are often subtle and require spicule/microscopic study for reliable identification).