Genus LAXIFENESTELLA Morozova, 1974

Type species. Fenestella sarytshevae Schulga-Nesterenko, 1951, subsequently designated by Morozova (1974). Mississippian, Serpukhovian; Moscow Syncline, Russia .

Diagnosis. Reticulate colonies consisting of relatively wide and thick branches and moderately wide dissepiments. Autozooecia arranged in two rows on the branches. Autozooecial chambers rectangular to pentagonal in mid-tangential section. Axial wall between autozooecial rows weakly undulating. Both superior and inferior hemisepta present. Narrow keel with single row of nodes developed (modified after Morozova 2001, p. 44).

Remarks. Laxifenestella Morozova, 1974, differs from Fenestella Lonsdale, 1839, in the rectangular to pentagonal shape of autozooecia in mid-tangential section and the presence of well-developed hemisepta.

Occurrence. Lower Devonian – Upper Permian; worldwide.