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Druggidium meerensis
Druggidium meerensis Slimani and Louwye, 2011, p.43–44. pl.1, figs.16–25, pl.2, figs.1–5.
Holotype: Slimani and Louwye, 2011, pl.1, figs.16–19.
Age: late Maastrichtian–early Danian.
Original description (Slimani and Louwye, 2011):
Druggidium meerensis sp. nov. (Plate I, 16–25; Plate II, 1–5)
Synonyms:
1994 Druggidium sp. A; Slimani, pp. 12–13, pl. 1, figs. 16–18, 31– 32.
1995 Druggidium sp. A; Slimani, unpublished Ph.D. Thesis, p. 171, table 3, pl. 1, figs. 16–18, 31–32, table 6.
2000 Druggidium sp. A; Slimani, table 3.
In press Druggidium sp. A of Slimani, 1994; Slimani et al., fig. 8c.
In press Druggidium sp. A of Slimani et al., table 1, fig. 8g.
Holotype: Slide Meer 848 m, preparation 1, EF N48/4 (Plate I, 16–19).
Repository: Botanical collection of the National Herbarium (RAB), Scientific Institute, Mohammed V-Agdal University, Rabat, Morocco.
Type locality: Meer (Antwerp province, northern Belgium), well no. 007E0205 of the Geological Survey of Belgium.
Stratigraphic horizon: Uppermost Maastrichtian, Meer 848 m borehole depth.
Etymology: Named for the Meer village, which is the type locality.
Diagnosis: An ovoidal to ellipsoidal, suturocavate Druggidium species with a granulate, vermiculate to rarely pseudoreticulate intratabular ornamentation. The archeopyle is precingular or combination, involving apical, anterior intercalary and precingular plates.
Description: This small proximate and suturocavate dinoflagellate cyst has an ovoidal to ellipsoidal ambitus. The hypocyst length is about 1/3 to 2/3 of the total cyst length, the rest is shared equally by the cingulum and epicyst. The cyst wall consists of a smooth endophragm with a maximum thickness of 1 μm and a smooth, hyaline and thin periphragm with a maximum thickness of 0.5 μm. The endophragm bears granules, short pillars and/or low irregular ridges, which support the periphragm distally. These ornaments may be thinly or densely dispersed, free or proximally interconnected and show a granulate to vermiculate or rarely pseudoreticulate wall surface. The endophragm in the sutural area is devoid of ornaments, and separated from the periphragm by cavate sutures, which reflect the tabulation. The periphragm in optical section is continuous, and protrudes rarely at the cavate sutures to form an apparent relief of crests. The reflected tabulation is ?1pr, 4′, 4a, 6″–?7″, 6c, 5″′–6″′, 1p, 1″″, 2s. The cingulum is relatively wide (up to 6 μm width) and slightly laevorotatory. The large posterior sulcal plate is omega-shaped. Some specimens possess a flagellar scar. The posterior intercalary (1p) and posterior sulcal (ps) plates show a partiform hypocystal arrangement. The archeopyle may be precingular of type P, 2P or rarely combination of type (AI)a2P. The type P archeopyle involves the release of plate 3″, while type 2P consists of a compound biplacoid operculum with both plates 3″ and 4″ free, or plate 4″ free and plate 3″ attached adcingularly. The type 2P(AI)a archeopyle has a compound operculum formed by one piece (apical and anterior intercalary plates) attached ventrally and two free pieces (plates 3″ and 4″).
Discussion: Druggidium meerensis sp. nov. is conspecific with Druggidium sp. A of Slimani (1994) and Druggidium sp. A of Slimani et al. (2011). The new species differs from all other Druggidium species in being suturocavate and in having a granulate, vermiculate to rarely pseudoreticulate intratabular ornamentation. The tabulation of this species is similar to that of Microdinium Cookson and Eisenack, 1960, emend. Slimani, 1994, which may be suturocavate. Specimens of Druggidium meerensis with intratabular processes resemble to Microdinium bensonii subsp. pilatum Slimani, 1994 and Microdinium mariae Slimani, 1994, while those with irregular intratabular ridges resemble Microdinium sp. A of Slimani (1994) and Microdinium minutum Louwye, 1997, but differ in having archeopyle types P, 2P or (AI) a2P, rather than type (tAtI)a. Specimens of the new species with a precingular archeopyle differ from species of the genus Corrudinium Stover and Evitt, 1978 in being suturocavate and partiform gonyaulacoid. Corrudinium species usually possess accessory intaratabular ridges and are sexiform gonyaulacoid. Alisocysta breviallata Harker et al., 1990 and Histiocysta palla of Foucher (1974) have a similar morphological appearance to the specimens of the new species with intratabular ridges, but differ distinctly in having an apical archeopyle.
Dimensions: Holotype length 28 μm, width 25 μm. Range: length 28 (29)33 μm, width 25(26)28 μm. Number of specimens measured: 10
Stratigraphic occurrence: Lower Danian of Turnhout (Slimani, 1994, 1995, 2000) and Upper Maastrichtian–Lower Danian of Meer (Slimani et al., 2011), northern Belgium.
Holotype: Slimani and Louwye, 2011, pl.1, figs.16–19.
Age: late Maastrichtian–early Danian.
Original description (Slimani and Louwye, 2011):
Druggidium meerensis sp. nov. (Plate I, 16–25; Plate II, 1–5)
Synonyms:
1994 Druggidium sp. A; Slimani, pp. 12–13, pl. 1, figs. 16–18, 31– 32.
1995 Druggidium sp. A; Slimani, unpublished Ph.D. Thesis, p. 171, table 3, pl. 1, figs. 16–18, 31–32, table 6.
2000 Druggidium sp. A; Slimani, table 3.
In press Druggidium sp. A of Slimani, 1994; Slimani et al., fig. 8c.
In press Druggidium sp. A of Slimani et al., table 1, fig. 8g.
Holotype: Slide Meer 848 m, preparation 1, EF N48/4 (Plate I, 16–19).
Repository: Botanical collection of the National Herbarium (RAB), Scientific Institute, Mohammed V-Agdal University, Rabat, Morocco.
Type locality: Meer (Antwerp province, northern Belgium), well no. 007E0205 of the Geological Survey of Belgium.
Stratigraphic horizon: Uppermost Maastrichtian, Meer 848 m borehole depth.
Etymology: Named for the Meer village, which is the type locality.
Diagnosis: An ovoidal to ellipsoidal, suturocavate Druggidium species with a granulate, vermiculate to rarely pseudoreticulate intratabular ornamentation. The archeopyle is precingular or combination, involving apical, anterior intercalary and precingular plates.
Description: This small proximate and suturocavate dinoflagellate cyst has an ovoidal to ellipsoidal ambitus. The hypocyst length is about 1/3 to 2/3 of the total cyst length, the rest is shared equally by the cingulum and epicyst. The cyst wall consists of a smooth endophragm with a maximum thickness of 1 μm and a smooth, hyaline and thin periphragm with a maximum thickness of 0.5 μm. The endophragm bears granules, short pillars and/or low irregular ridges, which support the periphragm distally. These ornaments may be thinly or densely dispersed, free or proximally interconnected and show a granulate to vermiculate or rarely pseudoreticulate wall surface. The endophragm in the sutural area is devoid of ornaments, and separated from the periphragm by cavate sutures, which reflect the tabulation. The periphragm in optical section is continuous, and protrudes rarely at the cavate sutures to form an apparent relief of crests. The reflected tabulation is ?1pr, 4′, 4a, 6″–?7″, 6c, 5″′–6″′, 1p, 1″″, 2s. The cingulum is relatively wide (up to 6 μm width) and slightly laevorotatory. The large posterior sulcal plate is omega-shaped. Some specimens possess a flagellar scar. The posterior intercalary (1p) and posterior sulcal (ps) plates show a partiform hypocystal arrangement. The archeopyle may be precingular of type P, 2P or rarely combination of type (AI)a2P. The type P archeopyle involves the release of plate 3″, while type 2P consists of a compound biplacoid operculum with both plates 3″ and 4″ free, or plate 4″ free and plate 3″ attached adcingularly. The type 2P(AI)a archeopyle has a compound operculum formed by one piece (apical and anterior intercalary plates) attached ventrally and two free pieces (plates 3″ and 4″).
Discussion: Druggidium meerensis sp. nov. is conspecific with Druggidium sp. A of Slimani (1994) and Druggidium sp. A of Slimani et al. (2011). The new species differs from all other Druggidium species in being suturocavate and in having a granulate, vermiculate to rarely pseudoreticulate intratabular ornamentation. The tabulation of this species is similar to that of Microdinium Cookson and Eisenack, 1960, emend. Slimani, 1994, which may be suturocavate. Specimens of Druggidium meerensis with intratabular processes resemble to Microdinium bensonii subsp. pilatum Slimani, 1994 and Microdinium mariae Slimani, 1994, while those with irregular intratabular ridges resemble Microdinium sp. A of Slimani (1994) and Microdinium minutum Louwye, 1997, but differ in having archeopyle types P, 2P or (AI) a2P, rather than type (tAtI)a. Specimens of the new species with a precingular archeopyle differ from species of the genus Corrudinium Stover and Evitt, 1978 in being suturocavate and partiform gonyaulacoid. Corrudinium species usually possess accessory intaratabular ridges and are sexiform gonyaulacoid. Alisocysta breviallata Harker et al., 1990 and Histiocysta palla of Foucher (1974) have a similar morphological appearance to the specimens of the new species with intratabular ridges, but differ distinctly in having an apical archeopyle.
Dimensions: Holotype length 28 μm, width 25 μm. Range: length 28 (29)33 μm, width 25(26)28 μm. Number of specimens measured: 10
Stratigraphic occurrence: Lower Danian of Turnhout (Slimani, 1994, 1995, 2000) and Upper Maastrichtian–Lower Danian of Meer (Slimani et al., 2011), northern Belgium.