Back
Lejeunecysta hatterasensis
Lejeunecysta hatterasensis Head and Norris, 2003, p.3-4,6, fig.4, nos.1-20.
Holotype: Head and Norris, 2003, fig.4, nos.10-13.
Age: Pliocene.
Original description (Head and Norris, 2003):
Lejeunecysta Hatterasensis new species
Lejeunecysta oliva (auct. non Reid, 1977) Turon & Londeix, 1988. Kolev, 1993, p. 53, pl. 4, fig. 11.
Diagnosis - Epicyst and hypocyst of approximately equal length, apical horn tapering to rounded apex, antapical horns tapering to sharp points. Cingulum nearly planar, marked on both margins by low crests with thickened bases. Entire surface of cyst covered by dense ornament of narrow, low (less than 0.5 mm high and wide), sinuous, anastomosing ridges and scattered granules. Low, faint sutural ridges on epi- and hypocyst incompletely reflect tabulation. Archeopyle 2a intercalary, asymmetrical iso-deltaform linteloid, well-developed angles, operculum free.
Description - Cysts proximate, medium brown in color, peridinioid, epicyst and hypocyst of approximately equal length; antapical horns of approximately equal development. Cysts have moderate dorso-ventral compression as primary feature; just two of 13 recorded specimens preserved in polar-compressed state. Sides of epicyst slightly convex, apical horn tapers to rounded apex that may be thickened (as on the holotype), although a thickened protuberance occasionally present. Lateral margins of hypocyst straight to slightly convex; antapical margin weakly to deeply incised. Antapical horns taper to sharp hollow points. Cingulum not indented to moderately indented and approximately planar; each margin marked by low (,1.0 µm) thin crest with thickened base. Sulcus broad and moderately incised; midventral flagellar scar sometimes present (e.g., Fig. 4.4). Dense ornament of narrow (less than 0.5 µm), sinuous, anastomosing ridges and scattered granules less than 0.5 µm high, appearing as dark lines, covers entire surface. These lines form a pattern radiating outwards from horn tips. Some radial lines on epicyst and hypocyst straighter and more prominent, presumably indicating plate boundaries. Wall layers closely appressed except for occasional separation at antapical horn tips into layers, where thickening is apparently restricted to inner wall layer. Archeopyle 2a intercalary, iso-deltaform linteloid with very short H3 and H5 slides (almost trapezoidal) and asymmetrical (e.g., Fig. 4.10–4.13) with right archeopyle margin more nearly vertical than left. Archeopyle shows no obvious offset relative to middorsal line.
Etymology - Named after the Hatteras Outer Ridge, an Upper Cenozoic sedimentary drift deposit into which Hole 603C was drilled.
Type - Holotype, sample DSDP 603C-28-6, 35–37 cm, slide 3 (ROM 55082); England Finder reference K34/0. Lower Pliocene. Figure 4.10–4.13.
Measurements - Holotype: Length 55 µm; breadth 67 µm. Range: Length 41(52.9)64 µm, standard deviation 8.9 µm; breadth 46(53.3)67 µm, standard deviation 6.3 µm. Thirteen specimens were measured.
Occurrence - Present in two separate intervals of the Lower and Upper Pliocene of DSDP Hole 603C, implying ecological control on its distribution.
Comparison - This species differs from all others of the genus in its distinctive ornament. Selenopemphix warriensis Biffi and Grignani, 1983, described from the Oligocene of the Niger Delta, has greater polar compression, appears to be less densely ornamented (‘‘wrinkled’’ according to Biffi and Grignani, 1983), and is larger (breadth, 85–120 µm).
Holotype: Head and Norris, 2003, fig.4, nos.10-13.
Age: Pliocene.
Original description (Head and Norris, 2003):
Lejeunecysta Hatterasensis new species
Lejeunecysta oliva (auct. non Reid, 1977) Turon & Londeix, 1988. Kolev, 1993, p. 53, pl. 4, fig. 11.
Diagnosis - Epicyst and hypocyst of approximately equal length, apical horn tapering to rounded apex, antapical horns tapering to sharp points. Cingulum nearly planar, marked on both margins by low crests with thickened bases. Entire surface of cyst covered by dense ornament of narrow, low (less than 0.5 mm high and wide), sinuous, anastomosing ridges and scattered granules. Low, faint sutural ridges on epi- and hypocyst incompletely reflect tabulation. Archeopyle 2a intercalary, asymmetrical iso-deltaform linteloid, well-developed angles, operculum free.
Description - Cysts proximate, medium brown in color, peridinioid, epicyst and hypocyst of approximately equal length; antapical horns of approximately equal development. Cysts have moderate dorso-ventral compression as primary feature; just two of 13 recorded specimens preserved in polar-compressed state. Sides of epicyst slightly convex, apical horn tapers to rounded apex that may be thickened (as on the holotype), although a thickened protuberance occasionally present. Lateral margins of hypocyst straight to slightly convex; antapical margin weakly to deeply incised. Antapical horns taper to sharp hollow points. Cingulum not indented to moderately indented and approximately planar; each margin marked by low (,1.0 µm) thin crest with thickened base. Sulcus broad and moderately incised; midventral flagellar scar sometimes present (e.g., Fig. 4.4). Dense ornament of narrow (less than 0.5 µm), sinuous, anastomosing ridges and scattered granules less than 0.5 µm high, appearing as dark lines, covers entire surface. These lines form a pattern radiating outwards from horn tips. Some radial lines on epicyst and hypocyst straighter and more prominent, presumably indicating plate boundaries. Wall layers closely appressed except for occasional separation at antapical horn tips into layers, where thickening is apparently restricted to inner wall layer. Archeopyle 2a intercalary, iso-deltaform linteloid with very short H3 and H5 slides (almost trapezoidal) and asymmetrical (e.g., Fig. 4.10–4.13) with right archeopyle margin more nearly vertical than left. Archeopyle shows no obvious offset relative to middorsal line.
Etymology - Named after the Hatteras Outer Ridge, an Upper Cenozoic sedimentary drift deposit into which Hole 603C was drilled.
Type - Holotype, sample DSDP 603C-28-6, 35–37 cm, slide 3 (ROM 55082); England Finder reference K34/0. Lower Pliocene. Figure 4.10–4.13.
Measurements - Holotype: Length 55 µm; breadth 67 µm. Range: Length 41(52.9)64 µm, standard deviation 8.9 µm; breadth 46(53.3)67 µm, standard deviation 6.3 µm. Thirteen specimens were measured.
Occurrence - Present in two separate intervals of the Lower and Upper Pliocene of DSDP Hole 603C, implying ecological control on its distribution.
Comparison - This species differs from all others of the genus in its distinctive ornament. Selenopemphix warriensis Biffi and Grignani, 1983, described from the Oligocene of the Niger Delta, has greater polar compression, appears to be less densely ornamented (‘‘wrinkled’’ according to Biffi and Grignani, 1983), and is larger (breadth, 85–120 µm).