Thorectidae Bergquist, 1978

Ekins, Merrick, Erpenbeck, Dirk, Debitus, Cécile, Petek, Sylvain, Mai, Tepoerau, Wörheide, Gert & Hooper, John N. A., 2023, Revision of the genus Fascaplysinopsis, the type species Fascaplysinopsis reticulata (Hentschel, 1912) (Porifera, Dictyoceratida, Thorectidae) and descriptions of two new genera and seven new species, Zootaxa 5346 (3), pp. 201-241 : 206

Family Thorectidae Bergquist, 1978

Diagnosis. From Cook & Bergquist (2002): Wide range of growth forms, from encrusting pads to massive, upright, lobose, caliculate or digitate structures. The surface may be armoured, and is frequently thrown into ridges and hollows. Where unarmoured the surface is typically conulose. The skeleton comprises primary, secondary and sometimes tertiary fibres. The skeletal reticulum is usually regular, frequently with almost perfectly rectangular meshes. The spongin fibres making up the anastomosing skeleton are laminated in crosssection, with clear zones of disjunction between successive layers. The central region of each fibre is a diffuse pith that is not sharply disjunct from the denser investing layer, as is the pith in the Verongiida , but merges into the outer layer. A pith is always evident in the primary fibres, though it may be obscured by an axial core of foreign material within fibres, and may extend into the secondary elements of the skeleton. Some fibres can become extremely stout, and in some genera may form light and simple, to strong, complex fascicles. Primary fibres can be greatly reduced in number, or difficult to distinguish from sub-primary fibres. Thorectids do not possess the fine filaments seen in Irciniidae species. The mesohyl is more collagenous than in the Spongiidae , and macroscopically can appear fleshy.