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Desmocysta hadra
Desmocysta hadra sp. nov.; Vieira, M. et al. 2020
Holotype: Vieira, M. et al. 2020, Plate 1, fig. 1; from a cutting sample at 3495 m; EF coordinates J57/3; central body length 58 μm, width 48 μm, length of filaments 15 μm.
Age: early Campanian
Original description: Vieira, M. et al. 2020: Desmocysta hadra sp. nov.
Diagnosis:
A subspherical to ovoidal dinoflagellate cyst with a two-plate precingular archaeopyle. The wall is thick, up to 2 μm, and highly folded with a scabrate–punctate surface. Fine, usually short filaments arise from a small area at the antapex.
Description:
The cyst is of intermediate size, subspherical to ovoidal in shape and highly folded. These folds usually seem to run approximately parallel to the margin of the cyst.
The wall is thick, up to 2 μm, and scabrate–punctate. The fine grana are well-developed, up to 3 μm, tending to concentrate in the lower third of the body where the filaments originate. The filaments are usually short, fine and thread-like (occasionally some specimens show longer filaments), arising from the antapex and usually less than 1/3 the length of the cyst.
Archaeopyle: two-plate precingular, and the operculum is usually free, although the opercular pieces can occasionally be seen inside the cyst (see Plate 1 – figs. 4 and 7). In some cysts it is possible to observe a small incision between the two archaeopyle plates. The presence of opercular pieces inside the cyst, together with a highly folded wall and well-developed granulation particularly concentrated in a small area where the filaments are attached to the antapex, is not reported in other Desmocysta species.
Dimensions:
Central body length 46(58)67 μm, width 43(49)61 μm, length of filaments 10(24)35 μm
Number of specimens measured: 20
Affinities:
This new species differs from D. plekta (Plate 2, figs. 1–4) by its larger size, thicker wall and shorter filaments, as well as from D. simplex (Plate 2, fig. 7) by its numerous, relatively short antapical filaments. Desmocysta californica (Plate 2, figs. 5–6) differs by the presence of granules and/or verrucae on its surface. Desmocysta hadra sp. nov. also differs from those species by its highly folded wall and the concentration of fine grana in the lower part of the body, particularly where the filaments originate
Holotype: Vieira, M. et al. 2020, Plate 1, fig. 1; from a cutting sample at 3495 m; EF coordinates J57/3; central body length 58 μm, width 48 μm, length of filaments 15 μm.
Age: early Campanian
Original description: Vieira, M. et al. 2020: Desmocysta hadra sp. nov.
Diagnosis:
A subspherical to ovoidal dinoflagellate cyst with a two-plate precingular archaeopyle. The wall is thick, up to 2 μm, and highly folded with a scabrate–punctate surface. Fine, usually short filaments arise from a small area at the antapex.
Description:
The cyst is of intermediate size, subspherical to ovoidal in shape and highly folded. These folds usually seem to run approximately parallel to the margin of the cyst.
The wall is thick, up to 2 μm, and scabrate–punctate. The fine grana are well-developed, up to 3 μm, tending to concentrate in the lower third of the body where the filaments originate. The filaments are usually short, fine and thread-like (occasionally some specimens show longer filaments), arising from the antapex and usually less than 1/3 the length of the cyst.
Archaeopyle: two-plate precingular, and the operculum is usually free, although the opercular pieces can occasionally be seen inside the cyst (see Plate 1 – figs. 4 and 7). In some cysts it is possible to observe a small incision between the two archaeopyle plates. The presence of opercular pieces inside the cyst, together with a highly folded wall and well-developed granulation particularly concentrated in a small area where the filaments are attached to the antapex, is not reported in other Desmocysta species.
Dimensions:
Central body length 46(58)67 μm, width 43(49)61 μm, length of filaments 10(24)35 μm
Number of specimens measured: 20
Affinities:
This new species differs from D. plekta (Plate 2, figs. 1–4) by its larger size, thicker wall and shorter filaments, as well as from D. simplex (Plate 2, fig. 7) by its numerous, relatively short antapical filaments. Desmocysta californica (Plate 2, figs. 5–6) differs by the presence of granules and/or verrucae on its surface. Desmocysta hadra sp. nov. also differs from those species by its highly folded wall and the concentration of fine grana in the lower part of the body, particularly where the filaments originate