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Phelodinium elongatum
Phelodinium elongatum Slimani et al., 2010, p.117–118, pl.3, fig.11: pl.7, figs.9–10; pl.8, figs.2–3.
Holotype: Slimani et al., 2010, pl.8, figs.2–3.
Age: late Maastrichtian–early Danian.
Original description (Slimani, 2010)
Diagnosis. Elongate, rounded pentagonal, thin-walled Phelodinium with delicate and wrinkled periphragm and short conical apical and antapical horns. When visible the cingulum is indicated by transverse irregular fine folds or ridges. Antapical depression shallow or absent. Intercalary archeopyle, expressed by loss of the intercalary 2a plate.
Description. Peridinioid, cornucavate, proximate, dorso-ventrally compressed cyst with a rounded pentagonal outline and a longer than wide central body. The antapical depression is shallow or absent. The apical horn is conical with a truncate to blunt end. The antapical horns are slender, of equal length and have slightly pointed ends. The cyst wall consists of a thin (about 0.5 μm) and smooth endophragm and a very thin (less than 0.5 μm), smooth, hyaline, delicate and finely wrinkled periphram. The endophragm is closely appressed to the periphragm except at the horns and occasionally along the hypocystal flanks. The cingulum is rarely visible and indicated by irregular fine folds or ridges. The sulcus is rarely expressed by a slight longitudinal depression and/or folds. When present, the intercalary archeopyle is of type 2a. The operculum is free.
Derivation of name. From Greek elongatus meaning elongate, with reference to the elongate shape of this species.
Holotype. Plate 8, figs. 2, 3, sample OH 6, slide 2, England Finder coordinates L57/2. Specimen dimensions: Total length 105 μm; central body length 89 μm; breadth 70 μm.
Paratype. Plate 7, figs. 9, 10, sample OH 10, slide 1, England Finder coordinates O46/2. Specimen dimensions: Total length 93 μm; central body length 80 μm; breadth 63 μm.
Type locality. Ouled Haddou section, north of Taza, northern Morocco.
Type stratum. Lower Danian, clayey marls, at 10 cm above the K–Pg boundary.
Dimensions of measured specimens. Total length 60(80)105 μm. Central body length 58(77)82 μm. Breadth 45(61)80 μm. (14 specimens measured).
Discussion. Phelodinium elongatum sp. nov. is characterized by its elongate and rounded pentagonal shape with or without antapical shallow depression and by its delicate and finely folded periphram with slightly expressed cingulum. It resembles Lejeunecysta globosa Biffi & Grignani 1983 in its overall shape but differs in being elongate and cornucavate. Phelodinium gaditanum (Riegel 1974) Riegel & Sarjeant 1982 differs from the new species in being wider than long with clearly expressed cingulum.
Stratigraphic occurrence. Samples OH 2–18, planktonic foraminiferal Abathomphalus mayaroensis Zone (Upper Maastrichtian) and Guembelitria cretacea and Parvularugoglobigerina eugubina zones (Lower Danian), Ouled Haddou section.
Holotype: Slimani et al., 2010, pl.8, figs.2–3.
Age: late Maastrichtian–early Danian.
Original description (Slimani, 2010)
Diagnosis. Elongate, rounded pentagonal, thin-walled Phelodinium with delicate and wrinkled periphragm and short conical apical and antapical horns. When visible the cingulum is indicated by transverse irregular fine folds or ridges. Antapical depression shallow or absent. Intercalary archeopyle, expressed by loss of the intercalary 2a plate.
Description. Peridinioid, cornucavate, proximate, dorso-ventrally compressed cyst with a rounded pentagonal outline and a longer than wide central body. The antapical depression is shallow or absent. The apical horn is conical with a truncate to blunt end. The antapical horns are slender, of equal length and have slightly pointed ends. The cyst wall consists of a thin (about 0.5 μm) and smooth endophragm and a very thin (less than 0.5 μm), smooth, hyaline, delicate and finely wrinkled periphram. The endophragm is closely appressed to the periphragm except at the horns and occasionally along the hypocystal flanks. The cingulum is rarely visible and indicated by irregular fine folds or ridges. The sulcus is rarely expressed by a slight longitudinal depression and/or folds. When present, the intercalary archeopyle is of type 2a. The operculum is free.
Derivation of name. From Greek elongatus meaning elongate, with reference to the elongate shape of this species.
Holotype. Plate 8, figs. 2, 3, sample OH 6, slide 2, England Finder coordinates L57/2. Specimen dimensions: Total length 105 μm; central body length 89 μm; breadth 70 μm.
Paratype. Plate 7, figs. 9, 10, sample OH 10, slide 1, England Finder coordinates O46/2. Specimen dimensions: Total length 93 μm; central body length 80 μm; breadth 63 μm.
Type locality. Ouled Haddou section, north of Taza, northern Morocco.
Type stratum. Lower Danian, clayey marls, at 10 cm above the K–Pg boundary.
Dimensions of measured specimens. Total length 60(80)105 μm. Central body length 58(77)82 μm. Breadth 45(61)80 μm. (14 specimens measured).
Discussion. Phelodinium elongatum sp. nov. is characterized by its elongate and rounded pentagonal shape with or without antapical shallow depression and by its delicate and finely folded periphram with slightly expressed cingulum. It resembles Lejeunecysta globosa Biffi & Grignani 1983 in its overall shape but differs in being elongate and cornucavate. Phelodinium gaditanum (Riegel 1974) Riegel & Sarjeant 1982 differs from the new species in being wider than long with clearly expressed cingulum.
Stratigraphic occurrence. Samples OH 2–18, planktonic foraminiferal Abathomphalus mayaroensis Zone (Upper Maastrichtian) and Guembelitria cretacea and Parvularugoglobigerina eugubina zones (Lower Danian), Ouled Haddou section.