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Spiniferites strictus
Spiniferites strictus Matsuoka, 1983b, p.136–137, pl.12, figs.5a–b,6.
Holotype: Matsuoka, 1983b, pl.12, figs.5a–b.
Age: Pliocene or younger.
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Original description: [Matsuoka, 1983b]:
Spiniferites strictus sp. nov.
PI. 12, figs. 5, 6
Derivation of name: Latin, strictus, drawn tight, with reference to the short stout processes.
Diagnosis: Intermediate cyst subspherical to ovoidal and having moderately thick wall. Processes made up of two types, gonal and intergonal. Both types short, tapering, bi- or trifurcate and bifid distally. Processes sometimes perforated near the proximal base. Archeopyle reduced, simple, precingular and formed by displacement of the 3" paraplate.
Holotype: KMD slide NNS 17-2 (19.3/144.3), pl. 12, fig. 5. Sample NNS 17, Nishiyama Formation - Pliocene or younger. Loc: Takatani-shinden, Nishiyama-cho, Niigata Prefecture, Central Japan.
Description: The intermediate proximochorate cyst is subspherical to ovoidal in shape, and consists of two layers, moderately thick periphragm with a smooth to granular surface and endophragm, adpressed between processes. The processes comprise relatively short tapering gonal and intergonal types. They have bi- or trifurcate second branches with bifid tips. Small perforation are sometimes observed near the proximal base of the processes. The parasutural septa are distinctive and somewhat membraneous. Some specimens have a small apical boss, but not always. The archeopyle is a reduced pentagonal precingular type derived from release of the 3' paraplate. The paratabulation is that of the genus.
Dimensions: Holotype: Length of cyst 67 μm, width of cyst 62 μm, thickness of wall ca. 2 μm, length of processes up to 12 μm. Other specimens: Length of cyst 53-67 μm, width of cyst 50-62 μm, length of processes 10-14 μm. Number of specimens measured: 10.
Occurrence: Rare to abundant in the Teradomari Formation, Shiiya Formation, and Nishiyama Formation and its equivalent formations (Late Miocene to Pliocene or younger).
Remarks: Spiniferites strictus sp. nov. is similar to S. bentori (RossiGNOL) in the cyst shape with an apical boss, but different from the latter in having many short intergonal processes.
Holotype: Matsuoka, 1983b, pl.12, figs.5a–b.
Age: Pliocene or younger.
-------------------------------------------------------------------------------------------------------------------------
Original description: [Matsuoka, 1983b]:
Spiniferites strictus sp. nov.
PI. 12, figs. 5, 6
Derivation of name: Latin, strictus, drawn tight, with reference to the short stout processes.
Diagnosis: Intermediate cyst subspherical to ovoidal and having moderately thick wall. Processes made up of two types, gonal and intergonal. Both types short, tapering, bi- or trifurcate and bifid distally. Processes sometimes perforated near the proximal base. Archeopyle reduced, simple, precingular and formed by displacement of the 3" paraplate.
Holotype: KMD slide NNS 17-2 (19.3/144.3), pl. 12, fig. 5. Sample NNS 17, Nishiyama Formation - Pliocene or younger. Loc: Takatani-shinden, Nishiyama-cho, Niigata Prefecture, Central Japan.
Description: The intermediate proximochorate cyst is subspherical to ovoidal in shape, and consists of two layers, moderately thick periphragm with a smooth to granular surface and endophragm, adpressed between processes. The processes comprise relatively short tapering gonal and intergonal types. They have bi- or trifurcate second branches with bifid tips. Small perforation are sometimes observed near the proximal base of the processes. The parasutural septa are distinctive and somewhat membraneous. Some specimens have a small apical boss, but not always. The archeopyle is a reduced pentagonal precingular type derived from release of the 3' paraplate. The paratabulation is that of the genus.
Dimensions: Holotype: Length of cyst 67 μm, width of cyst 62 μm, thickness of wall ca. 2 μm, length of processes up to 12 μm. Other specimens: Length of cyst 53-67 μm, width of cyst 50-62 μm, length of processes 10-14 μm. Number of specimens measured: 10.
Occurrence: Rare to abundant in the Teradomari Formation, Shiiya Formation, and Nishiyama Formation and its equivalent formations (Late Miocene to Pliocene or younger).
Remarks: Spiniferites strictus sp. nov. is similar to S. bentori (RossiGNOL) in the cyst shape with an apical boss, but different from the latter in having many short intergonal processes.