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- Modern Dinocyst Key
- transparent cysts
- Septa and processes
- Processes distally connected
- Nematosphaeropsis rigida
Nematosphaeropsis rigida
Zonneveld, K.A.F. and Pospelova V. (2015). A determination key for modern dinoflagellate cysts. Palynology 39 (3), 387- 407.
Field characteristics
Nematosphaeropsis rigida Wrenn 1988
Field characteristics:
Chorate trabeculate cyst with a slightly elongate to egg-shaped central body, and solid gonal processes that are expanded proximally and distally. The processes are subrounded to subtriangular in cross-section and joined to each other distally by pairs of solid penitabular trabeculae that are rounded in cross-section. The process bases and shafts are formed by strands that arise from the central body; the bases may be perforate proximally due to incomplete fusing of these strands. Tabulation is clearly reflected by variably developed sutural septa and pairs of solid penitabular trabeculae that connect the processes distally. Archeopyle is precingular (type P) .
Dimensions: Cyst body: 29 to 39 µm; length of process: 8 to 17 µm.
Motile affinity: Probably a cyst of Gonyaulax spp.
Stratigraphic range: Late Oligocene-Recent.
Comparison with other species:
This species appears as much more robust N. labyrinthus since its abulation is reflected by septa. As a consequence the archeopyle is often very well visible. The species is very rare.
Field characteristics:
Chorate trabeculate cyst with a slightly elongate to egg-shaped central body, and solid gonal processes that are expanded proximally and distally. The processes are subrounded to subtriangular in cross-section and joined to each other distally by pairs of solid penitabular trabeculae that are rounded in cross-section. The process bases and shafts are formed by strands that arise from the central body; the bases may be perforate proximally due to incomplete fusing of these strands. Tabulation is clearly reflected by variably developed sutural septa and pairs of solid penitabular trabeculae that connect the processes distally. Archeopyle is precingular (type P) .
Dimensions: Cyst body: 29 to 39 µm; length of process: 8 to 17 µm.
Motile affinity: Probably a cyst of Gonyaulax spp.
Stratigraphic range: Late Oligocene-Recent.
Comparison with other species:
This species appears as much more robust N. labyrinthus since its abulation is reflected by septa. As a consequence the archeopyle is often very well visible. The species is very rare.