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Phanerodinium belgicum
Phanerodinium belgicum Slimani and Louwye, 2011, p.48, pl.2, figs.12–18.
Holotype: Slimani and Louwye, 2011, pl.2, figs.12–14.
Type locality: Meer (Antwerp province, northern Belgium)
Age: late Maastrichtian.
Original description (Slimani & Louwye, 2011):
Diagnosis:
An ovoidal Phanerodinium species characterized by a microgranulate to vermiculate cyst wall. The cyst bears membranous sutural crests with entire to slightly undulate distal edges and occasional gonal distal extentions.
Description:
The small proximate dinoflagellate cyst is dorsoventrally slightly compressed and has an ovoidal shape with the maximum width across the posterior cingular sutural crest. The hypocyst is hemi-ovoidal and represents about 3/4 of the total cyst length. The epicyst is subtriangular and shares the anterior part of the cyst equally with the cingulum. The autophragm is microgranulate to vermiculate with a maximum thickness of 1.5 μm. The tabulation is reflected on the dorsal surface by membranous sutural crests. The ventral surface shows no indication of a tabulation pattern. Four precingular plates are observed (2″–5″), an unsegmented cingulum, four postcingular plates (2″′–5″′), one antapical plate (1″″) and a posterior intercalary (1p) plate. The two latter plates are not separated from the ventral surface by crests. The sulcal plates and the other adjacent plates are undifferentiated. The cingular crests and the postcingular sutural crests have entire to slightly undulate distal edges and gonal extensions,which are occasionally apparent distally. The suture between 3″ and 4″ is not visible. The rarely visible archeopyle is precingular and of type P. The operculum is formed by one plate (4″), attached adcingularly.
Discussion:
The new species is characterized by its ovoidal shape, the granulate to vermiculate wall surface and the membranous sutural crests. It is conspecific with Phanerodinium sp. A of Slimani (1994, 1995) and Slimani et al. (2011). It differs from all other Phanerodinium species by its granulate to vermiculate cyst wall. Phanerodinium
septatum Slimani, 1994 has also membranous sutural crests, but differs moreover from the new species by its elongate polygonal shape, the thinner cyst wall, and its higher septa with concave distal edges supported by long protruding gonal processes. Phanerodinium septatum Slimani, 1994 is furthermore distinguished by its antapical (1″″) and posterior intercalary (1p) plates, which are completely delimited by sutural crests. The other species of Phanerodinium differs from the new species mainly in having ornamented crests.
Dimensions:
Holotype overall length 25 μm, overall width 28 μm. Range: overall length 16(22)25 μm, overall width 17(22)28 μm, maximal high of crests 6 μm.
Number of specimens measured: 10
Holotype: Slimani and Louwye, 2011, pl.2, figs.12–14.
Type locality: Meer (Antwerp province, northern Belgium)
Age: late Maastrichtian.
Original description (Slimani & Louwye, 2011):
Diagnosis:
An ovoidal Phanerodinium species characterized by a microgranulate to vermiculate cyst wall. The cyst bears membranous sutural crests with entire to slightly undulate distal edges and occasional gonal distal extentions.
Description:
The small proximate dinoflagellate cyst is dorsoventrally slightly compressed and has an ovoidal shape with the maximum width across the posterior cingular sutural crest. The hypocyst is hemi-ovoidal and represents about 3/4 of the total cyst length. The epicyst is subtriangular and shares the anterior part of the cyst equally with the cingulum. The autophragm is microgranulate to vermiculate with a maximum thickness of 1.5 μm. The tabulation is reflected on the dorsal surface by membranous sutural crests. The ventral surface shows no indication of a tabulation pattern. Four precingular plates are observed (2″–5″), an unsegmented cingulum, four postcingular plates (2″′–5″′), one antapical plate (1″″) and a posterior intercalary (1p) plate. The two latter plates are not separated from the ventral surface by crests. The sulcal plates and the other adjacent plates are undifferentiated. The cingular crests and the postcingular sutural crests have entire to slightly undulate distal edges and gonal extensions,which are occasionally apparent distally. The suture between 3″ and 4″ is not visible. The rarely visible archeopyle is precingular and of type P. The operculum is formed by one plate (4″), attached adcingularly.
Discussion:
The new species is characterized by its ovoidal shape, the granulate to vermiculate wall surface and the membranous sutural crests. It is conspecific with Phanerodinium sp. A of Slimani (1994, 1995) and Slimani et al. (2011). It differs from all other Phanerodinium species by its granulate to vermiculate cyst wall. Phanerodinium
septatum Slimani, 1994 has also membranous sutural crests, but differs moreover from the new species by its elongate polygonal shape, the thinner cyst wall, and its higher septa with concave distal edges supported by long protruding gonal processes. Phanerodinium septatum Slimani, 1994 is furthermore distinguished by its antapical (1″″) and posterior intercalary (1p) plates, which are completely delimited by sutural crests. The other species of Phanerodinium differs from the new species mainly in having ornamented crests.
Dimensions:
Holotype overall length 25 μm, overall width 28 μm. Range: overall length 16(22)25 μm, overall width 17(22)28 μm, maximal high of crests 6 μm.
Number of specimens measured: 10