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Spiniferites strictus
From Fensome et al., 2019:
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.
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.