†Cystothalamia megacysta Finks 2010 (demosponge)
Demospongea - Agelasida - Guadalupiidae
Full reference: R. M. Finks. 2010. The sponge family Guadalupiidae in the Texas Permian. Journal of Paleontology 84(5):821-847
Belongs to Cystothalamia according to R. M. Finks 2010
Sister taxa: Cystothalamia adrianensis, Cystothalamia conica, Cystothalamia crassa, Cystothalamia distefanoi, Cystothalamia guadalupensis, Cystothalamia irregulara, Cystothalamia nana, Cystothalamia nodulifera, Cystothalamia surmaqensis
Type specimen: AMNH 44897
Ecology: stationary epifaunal suspension feeder