Some were smooth and attached to a surface at a flat point, others were polyhedral or ornamented with nodes, many were covered in bristles, and a few were even suspended above the seabed by a rope-like anchor of braided glass spicules.

[2][3] Reticulosans comprise the vast majority of Paleozoic hexactinellid diversity, though only a few species survived up to the Mesozoic.

[2][3] They may include the oldest sponge body fossil in the world: Palaeophragmodictya, from the late Ediacaran (~555 Ma), was originally described as a reticulosan based on its mesh-like surface texture.

[4] Ediacaran-type preservation has obscured any information about spicule structure, and some authors doubt that Palaeophragmodictya is a sponge in the first place.

[2] Like most other glass sponges, reticulosans had a skeleton of unfused macroscleres reinforced with microscopic microscleres.