sensu Maletz (2011b)

Noble, Paula, Aitchison, Jonathan C., Danelian, Taniel, Dumitrica, Paulian, Maletz, Jörg, Suzuki, Noritoshi, Cuvelier, Jessie, Caridroit, Martial & O’Dogherty, Luis, 2017, Taxonomy of Paleozoic radiolarian genera, Geodiversitas 39 (3), pp. 419-502 : 458

sensu Maletz (2011b)

Tetrentactinia Foreman, 1963: 282 . — Maletz 2011b: 387.

Somphoentactinia Nazarov, 1975b: 92 .

Spongentactinella Nazarov, 1975b: 91 .

TYPE SPECIES. — Tetrentactinia barysphaera Foreman, 1963 ( Foreman 1963: 282, pl. 7, fig. 9).

AGE AND LOCATION OF TYPE MATERIAL. — Upper Devonian, Huron member, Ohio Shale, USA.

TAXON CODE. — 167.

STATUS. — Valid.

DESCRIPTION. — “Internal spicule with four rays originating in a point and arranged like the axes of a tetrahedron (tetrahedral spicule), around which is developed a complete or incomplete spherical or subspherical shell, frequently spongy and frequently with secondary spines. The point of union of the rays of the spicule is generally eccentric. The external spines of many of the species are partly or wholly spongy, and this tendency is used as a basis for the inclusion in this genus of a few forms in which the nature of the internal spicule could not be determined. The tetrahedral spicule is the principal distinguishing character of this genus. The only described genus with which Tetrentactinia may be comparable is Ellipsostigma Hinde (1899a, p. 51) . The ellipsoidal form of the shell of that monotypic genus may not be sufficient basis for a generic distinction, but the median bar in Hinde’s figured specimen does seem to represent a significant difference, and leads one to suspect that the spicule may in fact have had at least six rays. The undescribed genus Tetraedroclathrum Deflandre (1960, p. 216, pl. 1) may be similar to or identical with Tetrentactinia .” ( Foreman 1963: 282).

REMARKS

Maletz (2011b) published a detailed discussion on Tetrentactinia Foreman, 1963 , which he placed in the Spongentactiniidae Nazarov, 1975 and provided the revised genus diagnosis “Spherical radiolarian with a point-centered, four-rayed spicule and a double-layered shell with a loosely hexagonal mesh structure; a layered and radial three-dimensional meshwork of bars and rays may be present on its surface, forming a ‘spongy’ mesh; four massive main spines formed from thin round rays as extensions of the spicular rays, surrounded by a relatively dense, fairly regular, radially and concentrically developed meshwork of beams and bars.” ( Maletz 2011b: 387).