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Spiniferites serratus
Spiniferites serratus Matsuoka, 1983
Holotype: Matsuoka, 1983, pl.14, figs.1a-c
Locus typicus: Ishiji Nishiyama-cho, Niigata Prefecture, Central Japan
Stratum typicum: Nishiyama Formation - Pliocene or younger.
Age: Pliocene or younger
Original diagnosis: Matsuoka 1983, p.135: Spiniferites serratus
Cyst subspherical in shape and polygonal to pentagonal in equatorial view. Gonal and intergonal processes membraneous, conical to subconical, and bi- or trifurcate. Their distal extremities bifid. Parasutural septa around the antapical paraplate on the dorsal side well developed and becoming membraneous. Archeopyle reduced precingular and formed by displacement of the paraplate 3".
Original description: Matsuoka 1983, p.136: Spiniferites serratus
The proximochorate cyst shows polygonal to pentagonal outline in equatorial view, and consists of two layers, periphragm and endophragm. The processes are gonal and intergonal, which are equal in length. Three or more intergonal processes observed between two adjacent gonal processes. Processes of both types are membraneous and conical to subconical. The gona~ type is trifurcate and the intergonal type is bifurcate. Botll types bear bifid distal tips. Parasutural septa become distinctly membraneous and are well developed on the dorsal side of the antapical paraplate as observed in Spiniferites mirabilis (Rossignol). The archeopyle is a reduced pentagonal and simple precingular type derived from loss of the 3" paraplate. The paratabulation is fundamentally represented as 4", 0a, 6", as, 6c, 6"", 1 p, 1"" and l+Xs.
Dimensions: Holotype: Length of cyst 50µm, width of cyst 48µm, length of processes ca. 9µm, height of
parasutural septa around the 1"" paraplate 12µm, width of parasutural septa around the 1"" paraplate 19µm, width of paracingulum 4.3µm. Other specimens: Length of cyst 45-54µm, width of cyst 47-50µm, length of processes 7-9µm, width of paracingulum 4.3-7.9µm. Number of specimens measured: 12.
Occurrence: Rare to abundant in the Nishiyama Formation and Haizume Formation (Pliocene to Early Pleistocene).
Remarks: Matsuoka 1983, p.136
Spiniferites serratus sp. nov. is characterized by the denticulate parasutural septa. This new species
apparently resembles S. dentatus (Gocht) described from Cretaceous sediments, but differs from the latter in having characteristic processes with furcate distal extremities, and also from S. mirabilis (Rossignol) in possessing many short conical to subconical intergonal processes.
Holotype: Matsuoka, 1983, pl.14, figs.1a-c
Locus typicus: Ishiji Nishiyama-cho, Niigata Prefecture, Central Japan
Stratum typicum: Nishiyama Formation - Pliocene or younger.
Age: Pliocene or younger
Original diagnosis: Matsuoka 1983, p.135: Spiniferites serratus
Cyst subspherical in shape and polygonal to pentagonal in equatorial view. Gonal and intergonal processes membraneous, conical to subconical, and bi- or trifurcate. Their distal extremities bifid. Parasutural septa around the antapical paraplate on the dorsal side well developed and becoming membraneous. Archeopyle reduced precingular and formed by displacement of the paraplate 3".
Original description: Matsuoka 1983, p.136: Spiniferites serratus
The proximochorate cyst shows polygonal to pentagonal outline in equatorial view, and consists of two layers, periphragm and endophragm. The processes are gonal and intergonal, which are equal in length. Three or more intergonal processes observed between two adjacent gonal processes. Processes of both types are membraneous and conical to subconical. The gona~ type is trifurcate and the intergonal type is bifurcate. Botll types bear bifid distal tips. Parasutural septa become distinctly membraneous and are well developed on the dorsal side of the antapical paraplate as observed in Spiniferites mirabilis (Rossignol). The archeopyle is a reduced pentagonal and simple precingular type derived from loss of the 3" paraplate. The paratabulation is fundamentally represented as 4", 0a, 6", as, 6c, 6"", 1 p, 1"" and l+Xs.
Dimensions: Holotype: Length of cyst 50µm, width of cyst 48µm, length of processes ca. 9µm, height of
parasutural septa around the 1"" paraplate 12µm, width of parasutural septa around the 1"" paraplate 19µm, width of paracingulum 4.3µm. Other specimens: Length of cyst 45-54µm, width of cyst 47-50µm, length of processes 7-9µm, width of paracingulum 4.3-7.9µm. Number of specimens measured: 12.
Occurrence: Rare to abundant in the Nishiyama Formation and Haizume Formation (Pliocene to Early Pleistocene).
Remarks: Matsuoka 1983, p.136
Spiniferites serratus sp. nov. is characterized by the denticulate parasutural septa. This new species
apparently resembles S. dentatus (Gocht) described from Cretaceous sediments, but differs from the latter in having characteristic processes with furcate distal extremities, and also from S. mirabilis (Rossignol) in possessing many short conical to subconical intergonal processes.