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Spiniferites asperulus
Spiniferites asperulus Matsuoka, 1983
Holotype: Matsuoka, 1983, pl.12, fig.2
Age: Pliocene or younger
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Original description: [Matsuoka, 1983b]:
Spiniferites asperulus sp. nov.
PI. 12, figs. 2-4, Text-Fig. 17
Derivation of name: Latin, asper, somewhat rough, with reference to the coasely granular surface of the cyst.
Diagnosis: Cyst intermediate, subspherical to ovoidal, and possessing moderately thick and granular wall surface. Processes mostly gonal, sometimes intergonal, membraneous at the proximal base, and bi- or trifurcate. Their long secondary branch bears bifid distal extremities. Parasuture relatively membraneous and ornamented with small grains. Archeopyle pentagonal in shape, reduced form, and derived from the 3" paraplate.
Holotype: KMD slide NNS 11-5 (12.0/130.8), pl. 12, fig. 2. Sample NNS 11, Nishiyama Forrnaton - Pliocene or younger. Loc: Nishiyama (Type location of this formation), Nishiyama-cho, Niigata Prefecture, Central Japan.
Description: The intermediate proximochorate cyst is subspherical to ovoidal in shape, and consists of two layers, periphragm and endophragm. The endophragm is relatively thick and smooth. The periphragm is thin and granular. The gonal processes are conical, and distal ends of secondary furcate branches are bifid. At the proximal base of these processes, parasutural septa become membraneous. Their surface has small grana. This ornamentation is especially well developed in both apical and antapical areas. The parasutural septa are weak but almost complete. The archeopyle is a simple and reduced precingular type made up of loss of the 3" paraplate. The paratabulation
basically coincides with the gonyaulacacean type.
Dimensions: Holotype: Length of cyst 69 μm, width of cyst 64 μm, length of processes in apical area 15.5 μm, length of processes in antapical area 24.1 μm, length of other processes up to 16 μm, Length of secondary branch of processes up to 10 μm, thickness of wall ca. 1.7 μm. Other specimens: Length of cyst 48-69 μm, width of cyst 45-64 μm, length of processes up to 16 μm. Number of specimens measured: 15.
Occurrence: Rare to several in the Teradomari Formation, Shiiya Formation, Nishiyama Formation and its equivalent formations, and Haizume Formation (Late Miocene to Early Pleistocene).
Remarks: Spiniferites asperulus sp. nov. is closely similar to S. wetzelii (DEFLANDRE), but differs from the latter in having characteristic gonal processes with granular and membraneous stalks. This new species is, also, different from S. membranaceus (ROSSIGNOL) in possessing a granular periphragm well developed at the apical and antapical areas and the long secondary branches of the processes.
Holotype: Matsuoka, 1983, pl.12, fig.2
Age: Pliocene or younger
-------------------------------------------------------------------------------------------------------------------------------
Original description: [Matsuoka, 1983b]:
Spiniferites asperulus sp. nov.
PI. 12, figs. 2-4, Text-Fig. 17
Derivation of name: Latin, asper, somewhat rough, with reference to the coasely granular surface of the cyst.
Diagnosis: Cyst intermediate, subspherical to ovoidal, and possessing moderately thick and granular wall surface. Processes mostly gonal, sometimes intergonal, membraneous at the proximal base, and bi- or trifurcate. Their long secondary branch bears bifid distal extremities. Parasuture relatively membraneous and ornamented with small grains. Archeopyle pentagonal in shape, reduced form, and derived from the 3" paraplate.
Holotype: KMD slide NNS 11-5 (12.0/130.8), pl. 12, fig. 2. Sample NNS 11, Nishiyama Forrnaton - Pliocene or younger. Loc: Nishiyama (Type location of this formation), Nishiyama-cho, Niigata Prefecture, Central Japan.
Description: The intermediate proximochorate cyst is subspherical to ovoidal in shape, and consists of two layers, periphragm and endophragm. The endophragm is relatively thick and smooth. The periphragm is thin and granular. The gonal processes are conical, and distal ends of secondary furcate branches are bifid. At the proximal base of these processes, parasutural septa become membraneous. Their surface has small grana. This ornamentation is especially well developed in both apical and antapical areas. The parasutural septa are weak but almost complete. The archeopyle is a simple and reduced precingular type made up of loss of the 3" paraplate. The paratabulation
basically coincides with the gonyaulacacean type.
Dimensions: Holotype: Length of cyst 69 μm, width of cyst 64 μm, length of processes in apical area 15.5 μm, length of processes in antapical area 24.1 μm, length of other processes up to 16 μm, Length of secondary branch of processes up to 10 μm, thickness of wall ca. 1.7 μm. Other specimens: Length of cyst 48-69 μm, width of cyst 45-64 μm, length of processes up to 16 μm. Number of specimens measured: 15.
Occurrence: Rare to several in the Teradomari Formation, Shiiya Formation, Nishiyama Formation and its equivalent formations, and Haizume Formation (Late Miocene to Early Pleistocene).
Remarks: Spiniferites asperulus sp. nov. is closely similar to S. wetzelii (DEFLANDRE), but differs from the latter in having characteristic gonal processes with granular and membraneous stalks. This new species is, also, different from S. membranaceus (ROSSIGNOL) in possessing a granular periphragm well developed at the apical and antapical areas and the long secondary branches of the processes.