Cambrian – Recent
Demospongia is an extant class of stationary intermediate-level epifaunal suspension feeders
Characteristics of the Class
- Composed of siliceous spicules, spicules and spongin, or spongin alone
- Spicules tetraxons or derivatives with fewer rays
- Can have foreign inclusions
- Gelatinosa with siliceous spicules, siliceous spicules and spongin, spongin alone, or no skeleton. Spicules tetraxons or derivatives with more or fewer rays. Megascleres and microscleres differentiated except in primitive examples; many forms with megascleres only, due to loss of the microscleres; some with microscleres only.
Treatise on Invertebrate Paleontology, Part E (1955):
- Architecture compact rhagon. Siliceous spicules, or spongin, or (commonly) both, or (rarely) neither present. Diverse sorts of foreign inclusions occur in many.