Back
Phthanoperidinium cornutum
Phthanoperidinium cornutum Heilmann-Clausen and Van Simaeys, 2005, p.178, pl.9, figs.1–5.
Holotype: Heilmann-Clausen and Van Simaeys, 2005, pl.9, fig.1–2.
Age: middle Eocene.
Original description (Heilmann-Clausen and Van Simaeys, 2005)
Description. Dinoflagellate cysts belonging to the genus Phthanoperidinium; the specimens have smooth parasutural crests that are highest at the corners of the paraplates. The crests form a well-developed apical horn. Occasionally, fine denticules occur at the distal endings of the crests. The limits of the paracingulum and parasulcus are well marked. Between both ends of the strongly helicoidal paracingulum, the parasulcus is relatively narrow, but it widens considerably towards the antapex and apex. The archeopyle is formed by the loss of paraplate 2a.
Derivation of name. From the Latin cornutus, meaning with horn.
Designation of holotype. Plate 9, figs.1, 2, Slide 2644 K3, England Finder coordinates Q36/2. MGUH 27783. Kysing-4 borehole, sample 2644, Middle Eocene. Specimen dimensions: Autocyst length 26 µm; autocyst breadth 20 µm.
Designation of paratype. Paratype 1: Plate 9, fig. 3, Slide 2646 J4, England Finder coordinates P39. MGUH 27784. Kysing-4 borehole, sample 2646, Middle Eocene. Paratype 2: Plate 9, fig. 4, Slide 2646 J4, England Finder coordinates P36. MGUH 27785. Kysing-4 borehole, sample 2646, Middle Eocene. Paratype 3: Plate 9, fig. 5, Slide 2646 J4, England Finder coordinates O39/ 4. MGUH 27786. Kysing-4 borehole, sample 2646, Middle Eocene.
Dimensions of measured specimens. Autocyst length 20 (25) 29 µm. Autocyst breadth 16 (18) 22 µm. (16 specimens measured).
Comparison. This species differs from Phthanoperidinium levimurum Bujak in Bujak et al. 1980 by having a non-granulate periphragm and by the occurrence of a long, sharp apical horn. Phthanoperidinium cornutum sp. nov. differs from Phthanoperidinium distinctum Bujak 1994 by having a much longer apical horn and by having thin, high parasutural crests. Both Phthanoperidinium distinctum and Phthanoperidinium levimurum differ from Phthanoperidinium cornutumsp. nov. in lacking the strongly helicoidal paracingulum.
Holotype: Heilmann-Clausen and Van Simaeys, 2005, pl.9, fig.1–2.
Age: middle Eocene.
Original description (Heilmann-Clausen and Van Simaeys, 2005)
Description. Dinoflagellate cysts belonging to the genus Phthanoperidinium; the specimens have smooth parasutural crests that are highest at the corners of the paraplates. The crests form a well-developed apical horn. Occasionally, fine denticules occur at the distal endings of the crests. The limits of the paracingulum and parasulcus are well marked. Between both ends of the strongly helicoidal paracingulum, the parasulcus is relatively narrow, but it widens considerably towards the antapex and apex. The archeopyle is formed by the loss of paraplate 2a.
Derivation of name. From the Latin cornutus, meaning with horn.
Designation of holotype. Plate 9, figs.1, 2, Slide 2644 K3, England Finder coordinates Q36/2. MGUH 27783. Kysing-4 borehole, sample 2644, Middle Eocene. Specimen dimensions: Autocyst length 26 µm; autocyst breadth 20 µm.
Designation of paratype. Paratype 1: Plate 9, fig. 3, Slide 2646 J4, England Finder coordinates P39. MGUH 27784. Kysing-4 borehole, sample 2646, Middle Eocene. Paratype 2: Plate 9, fig. 4, Slide 2646 J4, England Finder coordinates P36. MGUH 27785. Kysing-4 borehole, sample 2646, Middle Eocene. Paratype 3: Plate 9, fig. 5, Slide 2646 J4, England Finder coordinates O39/ 4. MGUH 27786. Kysing-4 borehole, sample 2646, Middle Eocene.
Dimensions of measured specimens. Autocyst length 20 (25) 29 µm. Autocyst breadth 16 (18) 22 µm. (16 specimens measured).
Comparison. This species differs from Phthanoperidinium levimurum Bujak in Bujak et al. 1980 by having a non-granulate periphragm and by the occurrence of a long, sharp apical horn. Phthanoperidinium cornutum sp. nov. differs from Phthanoperidinium distinctum Bujak 1994 by having a much longer apical horn and by having thin, high parasutural crests. Both Phthanoperidinium distinctum and Phthanoperidinium levimurum differ from Phthanoperidinium cornutumsp. nov. in lacking the strongly helicoidal paracingulum.