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Lejeunecysta izerzenensis
Lejeunecysta izerzenensis Slimani et al., 2008, p.340–342, figs.10A–F.
Holotype: Slimani et al., 2008, figs.10A–B.
Age: late Maastrichtian.
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Original description (Slimani et al., 2008):
Lejeunecysta izerzenensis sp. nov. Fig. 10
1967 Lejeunecysta sp., Drugg, p. 14, pl. 1, fig. 16.
?1975 Lejeunecysta sp., Jain et al., p. 12, pl. 6, fig. 66.
1995 Lejeunecysta sp. (cf. Phelodinium tricuspis), Schrank and Ibrahim, text-fig. 5, pl. 9, fig. 15.
Derivation of name. After Bou Izerzene Mountain in northern Morocco, where the type locality Ouled Haddou is situated.
Holotype. Sample OH 1, slide 1, EF L27 (Fig. 10A, B).
Type locality and stratigraphic horizon. Ouled Haddou section, north of Taza, northern Morocco; marls 1 m below the K/T boundary, upper Maastrichtian.
Diagnosis. Pentagonal, laevigate to chagrinate, thin-walled Lejeunecysta with a truncate to slightly bifid apical horn, two long, conical, pointed antapical horns, a prominent antapical depression, and a laevorotatory cingulum marked by two transverse denticulate septa. When visible, the archeopyle is intercalary, type 2a.
Description. Proximate, pentagonal, dorsoventrally compressed peridinioid autocyst. Cyst wall c. 0.5 µm thick, laevigate to chagrinate with a few longitudinal folds. Epicyst conical. Hypocyst and epicyst are of approximately equal length and have slightly concave sides. Apical and antapical horns often distally solid. Cingulum indicated by two denticulate septa c. 4 µm high (Fig. 10A). Sulcal area indicated by two longitudinal folds. Antapical depression, situated between the two long antapical horns, is prominent.
Dimensions (in µm). Holotype and range for 10 specimens measured: length 70, 40(63)80; width 74, 45(65)80.
Discussion. Lejeunecysta izerzenensis sp. nov. is similar to Lejeunecysta sp. of Drugg (1967, p. 14, pl. 1, fig. 16) and L. sp. cf. Phelodinium tricuspis of Schrank and Ibrahim (1995, text-fig. 5, pl. 9, fig. 15), especially with respect to the prominent antapical depression and the denticulate cingular septa. Lejeunecysta sp. of Jain et al. (1975, p. 12, pl. 6, fig. 66) is conspecific with the new species. Lejeunecysta cinctoria (Bujak in Bujak et al., 1980) Lentin and Williams, 1981 and L. lata Biffi and Grignani, 1983 also have denticulate septa indicating the cingulum, but they differ from L. izerzenensis in having a shallow rather than a prominent antapical depression. Lejeunecysta izerzenensis generally has the same overall morphology as Phelodinium magnificum (Stanley, 1965) Stover and Evitt, 1978, but differs in being acavate; L. decorinassa Srivastava, 1995 is larger and possesses a cingulum expressed by folds rather than denticulate septa.
Stratigraphic occurrence. Samples OH 1e19, planktonic foraminiferal Abpthomphalus mayaroensis Zone (Upper Maastrichtian), Guembelitria cretacea and Parvularugoglobigerina eugubina zones (lower Danian), Ouled Haddou section; MaastrichtianeDanian of Escarpado Canyon, California, USA (Drugg, 1967) and Lower Assam, India (Jain et al., 1975); Maastrichtian of northwest Egypt (Schrank and Ibrahim, 1995); Danian of Senegal (Jan du Chêne, 1988).
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Holotype: Slimani et al., 2008, figs.10A–B.
Age: late Maastrichtian.
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Original description (Slimani et al., 2008):
Lejeunecysta izerzenensis sp. nov. Fig. 10
1967 Lejeunecysta sp., Drugg, p. 14, pl. 1, fig. 16.
?1975 Lejeunecysta sp., Jain et al., p. 12, pl. 6, fig. 66.
1995 Lejeunecysta sp. (cf. Phelodinium tricuspis), Schrank and Ibrahim, text-fig. 5, pl. 9, fig. 15.
Derivation of name. After Bou Izerzene Mountain in northern Morocco, where the type locality Ouled Haddou is situated.
Holotype. Sample OH 1, slide 1, EF L27 (Fig. 10A, B).
Type locality and stratigraphic horizon. Ouled Haddou section, north of Taza, northern Morocco; marls 1 m below the K/T boundary, upper Maastrichtian.
Diagnosis. Pentagonal, laevigate to chagrinate, thin-walled Lejeunecysta with a truncate to slightly bifid apical horn, two long, conical, pointed antapical horns, a prominent antapical depression, and a laevorotatory cingulum marked by two transverse denticulate septa. When visible, the archeopyle is intercalary, type 2a.
Description. Proximate, pentagonal, dorsoventrally compressed peridinioid autocyst. Cyst wall c. 0.5 µm thick, laevigate to chagrinate with a few longitudinal folds. Epicyst conical. Hypocyst and epicyst are of approximately equal length and have slightly concave sides. Apical and antapical horns often distally solid. Cingulum indicated by two denticulate septa c. 4 µm high (Fig. 10A). Sulcal area indicated by two longitudinal folds. Antapical depression, situated between the two long antapical horns, is prominent.
Dimensions (in µm). Holotype and range for 10 specimens measured: length 70, 40(63)80; width 74, 45(65)80.
Discussion. Lejeunecysta izerzenensis sp. nov. is similar to Lejeunecysta sp. of Drugg (1967, p. 14, pl. 1, fig. 16) and L. sp. cf. Phelodinium tricuspis of Schrank and Ibrahim (1995, text-fig. 5, pl. 9, fig. 15), especially with respect to the prominent antapical depression and the denticulate cingular septa. Lejeunecysta sp. of Jain et al. (1975, p. 12, pl. 6, fig. 66) is conspecific with the new species. Lejeunecysta cinctoria (Bujak in Bujak et al., 1980) Lentin and Williams, 1981 and L. lata Biffi and Grignani, 1983 also have denticulate septa indicating the cingulum, but they differ from L. izerzenensis in having a shallow rather than a prominent antapical depression. Lejeunecysta izerzenensis generally has the same overall morphology as Phelodinium magnificum (Stanley, 1965) Stover and Evitt, 1978, but differs in being acavate; L. decorinassa Srivastava, 1995 is larger and possesses a cingulum expressed by folds rather than denticulate septa.
Stratigraphic occurrence. Samples OH 1e19, planktonic foraminiferal Abpthomphalus mayaroensis Zone (Upper Maastrichtian), Guembelitria cretacea and Parvularugoglobigerina eugubina zones (lower Danian), Ouled Haddou section; MaastrichtianeDanian of Escarpado Canyon, California, USA (Drugg, 1967) and Lower Assam, India (Jain et al., 1975); Maastrichtian of northwest Egypt (Schrank and Ibrahim, 1995); Danian of Senegal (Jan du Chêne, 1988).
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