Belongs within: Demospongiae.
The Solenoporaceae are an assemblage of calcified fossils that have been recognised from the Ordovician to the Miocene. Though historically recognised as red algae, at least the type species appears to be better interpreted as a sponge; the affinities of other species require reassessment (Riding 2004).
Characters (Riding 2004): Skeleton typically heavily calcified, nodular, internally composed of juxtaposed radial space-filling filaments or tubes, with or without cross-partitions.
<==Solenoporaceae [Solenoporeae, Solenoporideae]
|--SolenoporellaR04
|--LithocaulonR04
|--Neosolenopora patrini Mastrorilli 1955EB93
|--PseudosolenoporaBR98
|--PseudochaetetesR04
|--Parachaetetes Deninger 1906BB05
| `--*P. tornquistiBR98
`--Solenopora Dybowski 1877BR98
|--*S. spongioides Dybowsky 1877BB05
|--S. compacta (Billings 1862) [=Stromatopora compacta]BR98
`--S. paquettianaR04
*Type species of generic name indicated
References
[BB05] Bassi, D., J. C. Braga, E. Zakrevskaya & E. P. Radionova. 2005. Re-assessment of the type collections of corallinalean genera (Corallinales, Rhodophyta) described by V. P. Maslov. Palaeontology 48 (5): 929–945.
[BR98] Brooke, C., & R. Riding. 1998. Ordovician and Silurian coralline red algae. Lethaia 31: 185–195.
[EB93] Edwards, D., J. G. Baldauf, P. R. Brown, K. J. Dorning, M. Feist, L. T. Gallagher, N. Grambast-Fessard, M. B. Hart, A. J. Powell & R. Riding. 1993. ‘Algae’. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 15–40. Chapman & Hall: London.
[R04] Riding, R. 2004. Solenopora is a chaetetid sponge, not an alga. Palaeontology 47: 117–122.