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Filisphaera filifera ssp. pilosa
Filisphaera filifera pilosa Head (ed.) 1993; Emendation: Head, 1994b, p.237, as Filisphaera filifera subsp. pilosa.
Originally Filisphaera pilosa, subsequently (and now) Filisphaera filifera subsp. pilosa.
Original Diagnosis: Matsuoka and Bujak, 1988, p. 44-45: Spherical to sub-spherical cyst with two distinct ornament types on the surface and with neither apical nor antapical horns; short spines densely distributed and relatively large granules scattered randomly. No ornament reflects the paratabulation except the archeopyle. No features delimit either the paracingulum or parasulcus. Archeopyle precingular, formed by the loss of paraplate 3" .
Emended Diagnosis: Head (ed.) 1993, p. 237
Cysts spherical to ovoidal. Wall approximately 1.0 Ám thick and formed of two closely appressed layers, a very thin (about 0.1-0.2 llm) solid endophragm and thicker periphragm of interconnecting, narrow (about 0.2 Ám wide), nontabular septa that form a microreticulum. Lumina generally about 0.5Ám or less in diameter, but size is variable within an individual specimen, larger lumina have irregular polygonal shape. Archeopyle precingular, formed by the loss of paraplate 3'. Operculum free. There are no other indications of paratabulation.
Dimensions. Holotype: cyst diameter 55 x 61Ám, wall thickness ca. 1.0 Ám, diameter of lumina, up to about 1.2 Ám, mostly about 0.5Ám or less.
Discussion. Head (ed.) 1993, p. 237
The emended diagnosis provides new information about the surface ornament of the holotype which is microreticulate and not pileose. The large randomly scattered "granules" described in the original diagnosis are mineral grains adhering to the microreticulum. The archeopyle style could not be determined for the holotype. Two paratypes were observed but neither could be assigned definitively to Filisphaera filifera pilosa. One of these (Matsuoka and Bujak, 1988, pl.3, fig. 9a, 9b) is a detached precingular operculum whose wall thickness could not be determined. However, ornament compares closely with the holotype while having a higher proportion of lumina in the 0.5-1.2Ám range. The adapical margin of the operculum is conspicuously irregular and the angles of the adcingular margin are sharply pronounced. The other paratype (Matsuoka and Bujak, 1988, pl. 8, fig. 3) has ornament consisting of fine septa about 1.0 Ám high but precise details of the microreticulation could not be determined. This specimen possibly has a 2P archeopyle. The strew slide containing the holotype was searched for other specimens. None were confidently identified although several specimens resembling Filisphaera filifera filifera were seen. Consequently the present emendation of Filisphaera filifera pilosa is based on the holotype alone, its current taxonomic status pending detailed population studies of the species Filisphaera filifera to assess intraspecific variation.
Comparison. Head (ed.) 1993, p. 237
Filisphaera filifera subsp. pilosa is distinguished from F. filifera filifera by its lower periphragmal
septa: about 0.8 Ám for the holotype of F. filifera pilosa versus about 1.7-2.2Ám for F. filifera filifera. It differs from F. microornata in having finer periphragmal microreticulation: maximum diameter of lumina ca.1.2Ám for the holotype of Filisphaera filifera subsp. pilosa versus about 2.0-2.5 Ám for F. microornata.
Occurrence. The holotype of Filisphaera filifera subsp. pilosa is from the Lower or Upper Pliocene of the St. George Basin, Bering Sea.
Originally Filisphaera pilosa, subsequently (and now) Filisphaera filifera subsp. pilosa.
Original Diagnosis: Matsuoka and Bujak, 1988, p. 44-45: Spherical to sub-spherical cyst with two distinct ornament types on the surface and with neither apical nor antapical horns; short spines densely distributed and relatively large granules scattered randomly. No ornament reflects the paratabulation except the archeopyle. No features delimit either the paracingulum or parasulcus. Archeopyle precingular, formed by the loss of paraplate 3" .
Emended Diagnosis: Head (ed.) 1993, p. 237
Cysts spherical to ovoidal. Wall approximately 1.0 Ám thick and formed of two closely appressed layers, a very thin (about 0.1-0.2 llm) solid endophragm and thicker periphragm of interconnecting, narrow (about 0.2 Ám wide), nontabular septa that form a microreticulum. Lumina generally about 0.5Ám or less in diameter, but size is variable within an individual specimen, larger lumina have irregular polygonal shape. Archeopyle precingular, formed by the loss of paraplate 3'. Operculum free. There are no other indications of paratabulation.
Dimensions. Holotype: cyst diameter 55 x 61Ám, wall thickness ca. 1.0 Ám, diameter of lumina, up to about 1.2 Ám, mostly about 0.5Ám or less.
Discussion. Head (ed.) 1993, p. 237
The emended diagnosis provides new information about the surface ornament of the holotype which is microreticulate and not pileose. The large randomly scattered "granules" described in the original diagnosis are mineral grains adhering to the microreticulum. The archeopyle style could not be determined for the holotype. Two paratypes were observed but neither could be assigned definitively to Filisphaera filifera pilosa. One of these (Matsuoka and Bujak, 1988, pl.3, fig. 9a, 9b) is a detached precingular operculum whose wall thickness could not be determined. However, ornament compares closely with the holotype while having a higher proportion of lumina in the 0.5-1.2Ám range. The adapical margin of the operculum is conspicuously irregular and the angles of the adcingular margin are sharply pronounced. The other paratype (Matsuoka and Bujak, 1988, pl. 8, fig. 3) has ornament consisting of fine septa about 1.0 Ám high but precise details of the microreticulation could not be determined. This specimen possibly has a 2P archeopyle. The strew slide containing the holotype was searched for other specimens. None were confidently identified although several specimens resembling Filisphaera filifera filifera were seen. Consequently the present emendation of Filisphaera filifera pilosa is based on the holotype alone, its current taxonomic status pending detailed population studies of the species Filisphaera filifera to assess intraspecific variation.
Comparison. Head (ed.) 1993, p. 237
Filisphaera filifera subsp. pilosa is distinguished from F. filifera filifera by its lower periphragmal
septa: about 0.8 Ám for the holotype of F. filifera pilosa versus about 1.7-2.2Ám for F. filifera filifera. It differs from F. microornata in having finer periphragmal microreticulation: maximum diameter of lumina ca.1.2Ám for the holotype of Filisphaera filifera subsp. pilosa versus about 2.0-2.5 Ám for F. microornata.
Occurrence. The holotype of Filisphaera filifera subsp. pilosa is from the Lower or Upper Pliocene of the St. George Basin, Bering Sea.