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Corrudinium labradori
Corrudinium? labradorii Head et al., 1989
Head et al., 1989, questionably included this species in Corrudinium.
Since the epithet is based on a geographic locality, a preferable epithet would have been labradorense (I.C.N. Recommendation 60D). However, in the interests of stability, we do not correct the original spelling.
Holotype: Head et al., 1989, pl.3, figs.1-3,5-6
Locus typicus: ODP leg 105, site 646, Labrador Sea
Stratum typicum: Late Miocene-Early Pliocene
Original diagnosis: Head et al., 1989, p.456
Cysts small, spherical, proximate, and autophragmal. Surface smooth, with a fine network of narrow sinuous crests that form a nearly complete reticulum. Paratabulation presumably gonyaulacacean and weakly reflected by the presence of certain more prominent crests, which may be slightly broader, higher, and/or straighter than others. Archeopyle precingular Type 2P, operculum free, probably compound.
Dimensions. Holotype: Cyst diameter, including crests, 27 µm. Range in cyst diameter, including crests, 25(27.9)31 µm. Maximum diameter of lacunae up to about 2.5 to 3.0 µm. Crest height about 1.0 to 1.5 µm. Sixteen specimens were measured.
Original description: Head et al., 1989, p.456
Cysts are small with a delicate and fine reticulate ornament. Crest tops are parallel to cyst surface or are slightly undulate. Paratabulation may be partially and incompletely expressed by more prominent parasutural crests. Such traces of paratabulation were seen in 75% of the specimens found. The paracingulum was recognized on some specimens, as was a large paraplate on the hypocyst, interpreted to represent a single antapical paraplate. For each of the 10 specimens in which the archeopyle style could be determined, a Type 2P archeopyle with free operculum was observed. The operculum appears to be compound, based on a single separated and detached opercular paraplate found within one cyst. Specific precingular paraplates involved in archeopyle formation could not be determined with certainty, although these might be paraplates 2"" and 3"" for the specimen illustrated in Plate 3, Figure 9.
Affinities:
Head et al., 1989, p.456: Both Corrudinium harlandii Matsuoka, 1983, from the Pliocene to lower Pleistocene of Japan, and "?Ellipsodinium sp." of Harland, 1979 (synonymized with Corrudinium harlandii by Matsuoka, 1983) from the lower Pliocene of the Bay of Biscay, differ from C.? Iabradori in their larger sizes (40-53 Ám for C. harlandii; 36 Ám for ?Ellipsodinium sp.), in having less fine reticulate ornament that more completely expresses paratabulation and in apparently possessing a Type P precingular archeopyle. C.? Iabradori was provisionally assigned to Corrudinium owing to its possession of a Type 2P archeopyle.
Head et al., 1989, questionably included this species in Corrudinium.
Since the epithet is based on a geographic locality, a preferable epithet would have been labradorense (I.C.N. Recommendation 60D). However, in the interests of stability, we do not correct the original spelling.
Holotype: Head et al., 1989, pl.3, figs.1-3,5-6
Locus typicus: ODP leg 105, site 646, Labrador Sea
Stratum typicum: Late Miocene-Early Pliocene
Original diagnosis: Head et al., 1989, p.456
Cysts small, spherical, proximate, and autophragmal. Surface smooth, with a fine network of narrow sinuous crests that form a nearly complete reticulum. Paratabulation presumably gonyaulacacean and weakly reflected by the presence of certain more prominent crests, which may be slightly broader, higher, and/or straighter than others. Archeopyle precingular Type 2P, operculum free, probably compound.
Dimensions. Holotype: Cyst diameter, including crests, 27 µm. Range in cyst diameter, including crests, 25(27.9)31 µm. Maximum diameter of lacunae up to about 2.5 to 3.0 µm. Crest height about 1.0 to 1.5 µm. Sixteen specimens were measured.
Original description: Head et al., 1989, p.456
Cysts are small with a delicate and fine reticulate ornament. Crest tops are parallel to cyst surface or are slightly undulate. Paratabulation may be partially and incompletely expressed by more prominent parasutural crests. Such traces of paratabulation were seen in 75% of the specimens found. The paracingulum was recognized on some specimens, as was a large paraplate on the hypocyst, interpreted to represent a single antapical paraplate. For each of the 10 specimens in which the archeopyle style could be determined, a Type 2P archeopyle with free operculum was observed. The operculum appears to be compound, based on a single separated and detached opercular paraplate found within one cyst. Specific precingular paraplates involved in archeopyle formation could not be determined with certainty, although these might be paraplates 2"" and 3"" for the specimen illustrated in Plate 3, Figure 9.
Affinities:
Head et al., 1989, p.456: Both Corrudinium harlandii Matsuoka, 1983, from the Pliocene to lower Pleistocene of Japan, and "?Ellipsodinium sp." of Harland, 1979 (synonymized with Corrudinium harlandii by Matsuoka, 1983) from the lower Pliocene of the Bay of Biscay, differ from C.? Iabradori in their larger sizes (40-53 Ám for C. harlandii; 36 Ám for ?Ellipsodinium sp.), in having less fine reticulate ornament that more completely expresses paratabulation and in apparently possessing a Type P precingular archeopyle. C.? Iabradori was provisionally assigned to Corrudinium owing to its possession of a Type 2P archeopyle.