Back
Hystrichosphaera perforata
Hystrichosphaera perforata Davey and Williams 1966
Now Spiniferites. Originally Hystrichosphaera, subsequently (and now) Spiniferites.
Holotype: Davey and Williams, 1966, pl.5, fig.7; Bujak et al., 1980, pl.5, figs.2-3
Locus typicus: London Clay, Kent, England
Stratum typicum: Early Eocene
Original diagnosis: Davey and Williams, 1966, p. 41
A species of Hystrichosphaera with smooth surfaced central body bearing both gonal and sutural processes. Processes either tri- or tetra-linguate, cylindrical and open with net-like perforations distally, or taeniate, being bi- or trifurcate distally. Medial branching of processes may occur. Tabulation typical of genus with plate 6" having a triangular outline.
Dimensions: holotype: diameter of central body 40.5 by 50 Ám, length of processes
up to 26 Ám. Range: diameter of central body 28-50 Ám, length of processes 15-26 Ám.
Original description: Davey and Williams, 1966, p. 41
H. perforata sp. nov. is characterized by two types of processes: (I) gonal processes being open, cylindrical with tri- or tetra-linguate margins and possessing a triangular cross-section, and (2) taeniate processes being sutural in position. The processes are united by proximal membranes, of varying height, often with serrate edges, running along the plate boundaries. The open gonal processes are strongly fenestrate distally on the secae and occasionally along their length. A few of the processes are similar to those of H. ramosa var. ramosa in being closed distally. Each seca is usually distally bifid. The sutural processes are perforate distally where they bi- or trifurcate, and sometimes medially.
Affinities:
Davey and Williams, 1966, p. 41: Two specimens of H. ramosa which were recorded by Gerlach (1961) possessed processes perforate distally and along their length. All the processes of these two specimens are, however, closed and the perforations are in the form of small circular holes and not net-like as in H. perforata. H. porosa (Manum & Cookson 1964) from the Upper Cretaceous of Canada possesses similar, but shorter and broader, perforate processes and a characteristic reflected tabulation 1", 5", 5c, 5""", 1"""".
Now Spiniferites. Originally Hystrichosphaera, subsequently (and now) Spiniferites.
Holotype: Davey and Williams, 1966, pl.5, fig.7; Bujak et al., 1980, pl.5, figs.2-3
Locus typicus: London Clay, Kent, England
Stratum typicum: Early Eocene
Original diagnosis: Davey and Williams, 1966, p. 41
A species of Hystrichosphaera with smooth surfaced central body bearing both gonal and sutural processes. Processes either tri- or tetra-linguate, cylindrical and open with net-like perforations distally, or taeniate, being bi- or trifurcate distally. Medial branching of processes may occur. Tabulation typical of genus with plate 6" having a triangular outline.
Dimensions: holotype: diameter of central body 40.5 by 50 Ám, length of processes
up to 26 Ám. Range: diameter of central body 28-50 Ám, length of processes 15-26 Ám.
Original description: Davey and Williams, 1966, p. 41
H. perforata sp. nov. is characterized by two types of processes: (I) gonal processes being open, cylindrical with tri- or tetra-linguate margins and possessing a triangular cross-section, and (2) taeniate processes being sutural in position. The processes are united by proximal membranes, of varying height, often with serrate edges, running along the plate boundaries. The open gonal processes are strongly fenestrate distally on the secae and occasionally along their length. A few of the processes are similar to those of H. ramosa var. ramosa in being closed distally. Each seca is usually distally bifid. The sutural processes are perforate distally where they bi- or trifurcate, and sometimes medially.
Affinities:
Davey and Williams, 1966, p. 41: Two specimens of H. ramosa which were recorded by Gerlach (1961) possessed processes perforate distally and along their length. All the processes of these two specimens are, however, closed and the perforations are in the form of small circular holes and not net-like as in H. perforata. H. porosa (Manum & Cookson 1964) from the Upper Cretaceous of Canada possesses similar, but shorter and broader, perforate processes and a characteristic reflected tabulation 1", 5", 5c, 5""", 1"""".