Back
Cerodinium mediterraneum
Cerodinium mediterraneum, Slimani et al., 2008, p.340, figs.9G–L.
Holotype: Slimani et al., 2008, figs.9G–H.
Paratype: Slimani et al., 2008, fig. 9I, L
Type locality and stratigraphic horizon: Ouled Haddou section, north of Taza, northern Morocco, clayey marls 35 cm above the K/T boundary, lower Danian.
Stratigraphic occurrence: planktonic foraminiferal Guembelitria cretacea and Parvularugoglobigerina eugubina zones (lower Danian), Ouled Haddou section; Paleocene of southwest Manitoba, Canada (Kurita and McIntyre, 1995) and lower Campanianeupper Maastrichtian of the Côte d’Ivoire-Ghana transform margin (Oboh-Ikuenobe et al., 1998).
Age: early Danian.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Slimani et al., 2008]:
Diagnosis:
Small ovoid, convex-sided, thin-walled Cerodinium with narrow pericoels separating horns from endocyst. Cingulum indicated by transverse ledges or folds. Sulcus expressed by a longitudinal depression and folds. Intercalary archeopyle of standard hexa type, expressed by loss of intercalary plate 2a.
Description:
Peridinioid, proximate, bicavate to circumcavate, dorsoventrally compressed cyst, which consists of a thin (<0.5 µm), smooth endophragm and a thinner, smooth, finely folded periphram.
Endocyst generally oval, only slightly smaller than pericyst. Apical horn conical with a blunt tip, broadening proximally to merge with epipericyst.
Antapical horns elongate, more or less equal in size, broad-based and tapering distally to pointed tips. They are separated from endocyst by a hypo-pericoel.
Slightly laevorotatory cingulum is indicated by transverse ledges or folds.
Sulcus is indicated by a slight longitudinal depression of periphragm, often delimited between two longitudinal folds, which are sometimes extended to distal ends of antapical horns (Fig. 9H).
When developed, intercalary archeopyle is of type 2a (Fig. 9G) and located on mid-dorsal line. Operculum is free.
Dimensions (in µm):
Holotype, paratype and range for 13 specimens measured: overall length 86, 65, 57(69)86; length excluding horns 55, 35, 35(41)55; overall width 50, 42, 40(45)50.
Affinities/Discussion:
Cerodinium mediterraneum sp. nov. closely resembles Senegalinium sp. of Kurita and McIntyre (1995, text-figs 3, 4, p. 133, pl. 2, figs 7, 8) and Cerodinium sp. A of Oboh-Ikuenobe et al. (1998, fig. 2, pl. 4, figs 2, 3). Alterbidinium? bicellula (Islam, 1983) Lentin and Williams, 1985 is similar in shape and also bicavate, but differs in being smaller and in having relatively short and unequal antapical horns. Cerodinium depressum (Morgenroth, 1966) Lentin and Williams, 1987 is smaller, has a longitudinally striated periphragm, and much more developed pericoels in comparison to the size of the cyst; C. bolniense (Riegel, 1974) Lentin and Williams, 1989 is larger, has a pentagonal outline, a striated periphragm, and an endocyst that completely fills the pericyst. However, the specimen included in C. boloniense and interpreted by Riegel (1974, pl. 1, fig. 6) as an unusually small form with convex sides resembles C. mediterraneum.
Holotype: Slimani et al., 2008, figs.9G–H.
Paratype: Slimani et al., 2008, fig. 9I, L
Type locality and stratigraphic horizon: Ouled Haddou section, north of Taza, northern Morocco, clayey marls 35 cm above the K/T boundary, lower Danian.
Stratigraphic occurrence: planktonic foraminiferal Guembelitria cretacea and Parvularugoglobigerina eugubina zones (lower Danian), Ouled Haddou section; Paleocene of southwest Manitoba, Canada (Kurita and McIntyre, 1995) and lower Campanianeupper Maastrichtian of the Côte d’Ivoire-Ghana transform margin (Oboh-Ikuenobe et al., 1998).
Age: early Danian.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Slimani et al., 2008]:
Diagnosis:
Small ovoid, convex-sided, thin-walled Cerodinium with narrow pericoels separating horns from endocyst. Cingulum indicated by transverse ledges or folds. Sulcus expressed by a longitudinal depression and folds. Intercalary archeopyle of standard hexa type, expressed by loss of intercalary plate 2a.
Description:
Peridinioid, proximate, bicavate to circumcavate, dorsoventrally compressed cyst, which consists of a thin (<0.5 µm), smooth endophragm and a thinner, smooth, finely folded periphram.
Endocyst generally oval, only slightly smaller than pericyst. Apical horn conical with a blunt tip, broadening proximally to merge with epipericyst.
Antapical horns elongate, more or less equal in size, broad-based and tapering distally to pointed tips. They are separated from endocyst by a hypo-pericoel.
Slightly laevorotatory cingulum is indicated by transverse ledges or folds.
Sulcus is indicated by a slight longitudinal depression of periphragm, often delimited between two longitudinal folds, which are sometimes extended to distal ends of antapical horns (Fig. 9H).
When developed, intercalary archeopyle is of type 2a (Fig. 9G) and located on mid-dorsal line. Operculum is free.
Dimensions (in µm):
Holotype, paratype and range for 13 specimens measured: overall length 86, 65, 57(69)86; length excluding horns 55, 35, 35(41)55; overall width 50, 42, 40(45)50.
Affinities/Discussion:
Cerodinium mediterraneum sp. nov. closely resembles Senegalinium sp. of Kurita and McIntyre (1995, text-figs 3, 4, p. 133, pl. 2, figs 7, 8) and Cerodinium sp. A of Oboh-Ikuenobe et al. (1998, fig. 2, pl. 4, figs 2, 3). Alterbidinium? bicellula (Islam, 1983) Lentin and Williams, 1985 is similar in shape and also bicavate, but differs in being smaller and in having relatively short and unequal antapical horns. Cerodinium depressum (Morgenroth, 1966) Lentin and Williams, 1987 is smaller, has a longitudinally striated periphragm, and much more developed pericoels in comparison to the size of the cyst; C. bolniense (Riegel, 1974) Lentin and Williams, 1989 is larger, has a pentagonal outline, a striated periphragm, and an endocyst that completely fills the pericyst. However, the specimen included in C. boloniense and interpreted by Riegel (1974, pl. 1, fig. 6) as an unusually small form with convex sides resembles C. mediterraneum.