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Microdinium mariae
From Fensome et al., 2019:
Microdinium mariae Slimani, 1994, p.37–38, pl.4, figs.10–12,26–27,32–34. Holotype: Slimani, 1994, pl.4, figs.10–12,32–34. Age: late Campanian–earliest Danian.
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Original description (Slimani 1994):
Microdinium mariae sp. nov. (P1.4, Figs. 10-12, 26, 27, 32-34)
Name derivation: In honor of Dr. Marie-Josephe SONCIN I (Louis Pasteur University, Strasbourg, France), who discovered the same type of cyst (see synonymy below).
Hololvpe: Turnhout -775.01 m, preparation 5, E.F. coord. Q34.
Type locality: Turnhout -775.01 m.
Type horizon: Maastrichtian.
Synonymy:
1976: Microdinium sp. 2 - SCHUMACKER-LAMBRY and CHATEAUNEUF, p. 270, pl. 1, fig. 7-8.
1988: Elytrocysta druggii - SONCINI and RAUSCHER, Table 1, pl. 3, fig. 6-8.
1990: Microdinium sp. in SONCINI, p. 86, pl. 13, fig. 18-19.
Diagnosis: Small, proximal, acavate, subspheroidal to ellipsoidal cyst with a circular equatorial section; the epicyst is slightly smaller than the hypocyst. It is characterized by the presence of thin, short intratabular processes that are connected distally, giving the surface a vermiculated to reticulate appearance. The paratabulation is of the gonyaulacoid type and corresponds to the formula: lpr. 4', 4a, 6 - 7", 6 - 7c, 6'", lp, 1"", 5s; it is indicated by parasutural furrows devoid of ornamentation. The archaeopyle is apical and intercalary of the (tAtl)a type with an operculum attached ventrally.
Dimensions: Holotype. Length: 40 µm, width: 30 µm. Variations: Length: 30-36 µm, width: 22-28 µm. Number of specimens measured: 18.
Material: > 40 specimens.
Description: The autophragm (1-2 µm thick) is smooth and bears numerous intratabular processes that are solid, rigid, flared at their distal end, of uniform height (2-4 µm), and regularly distributed. The arrangement of the hypocystal paraplates is partiform; the sulcal paraplates as, fm, is, and rs are discernible; the posterior sulcal paraplate is wider and subomegaform; the paracingulum (4 µm in average width) is very weakly laevorotatory or non-spiral. The operculum (12 µm long in Phototype) is composed of 4 apical paraplates, 4 anterior intercalary paraplates and 1 preapical paraplate.
Note: Microdinium mariae sp. nov. is characterized by its small, fused intratabular processes, its flared distal end, and the absence of ornamentation along the parasutures. Its ornamentation is reminiscent of Chiamydophorella (COOKSON and EISENACK ) DUXBURY (1983), but its assignment to the genus Mkrodinium is based on its partiform paratabulation type and especially its apical and intercalary archaeopyle. Although its size is smaller, it is very closely comparable to Moroccan specimens (see synonymy above). It slightly resembles Microdinium sp. 2 found in the Belgian Paleocene by SCHUMACKER-LAMBRY and CHATEAUNEUF (1976). Paratabulation in Fibradinium? densibaculaium (BELOW . 1987b) LENTIN and WILLIAMS (1989) is also indicated by a stop of ornamentation along parasutures but differs from the studied species by its smaller size and its shorter and denser ornamentation without distal connections. Eisenackia? santketum (BELOW , 1987b) LENTIN AND WILLIAMS (1989) has an irregular ornamentation and different from that of Microdinium mariae.
Stratigraphic distribution: Turnhout: -956 to -759.89 m, Upper Campanian - Late Upper Maastrichtian, Early Danian. SONCIN I and RAUSCHE R (1988) and in SONCIN I (1990), Upper Maastrichtian - Paleocene, Phosphate of Ouled Abdoun, Morocco.
Microdinium mariae Slimani, 1994, p.37–38, pl.4, figs.10–12,26–27,32–34. Holotype: Slimani, 1994, pl.4, figs.10–12,32–34. Age: late Campanian–earliest Danian.
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Original description (Slimani 1994):
Microdinium mariae sp. nov. (P1.4, Figs. 10-12, 26, 27, 32-34)
Name derivation: In honor of Dr. Marie-Josephe SONCIN I (Louis Pasteur University, Strasbourg, France), who discovered the same type of cyst (see synonymy below).
Hololvpe: Turnhout -775.01 m, preparation 5, E.F. coord. Q34.
Type locality: Turnhout -775.01 m.
Type horizon: Maastrichtian.
Synonymy:
1976: Microdinium sp. 2 - SCHUMACKER-LAMBRY and CHATEAUNEUF, p. 270, pl. 1, fig. 7-8.
1988: Elytrocysta druggii - SONCINI and RAUSCHER, Table 1, pl. 3, fig. 6-8.
1990: Microdinium sp. in SONCINI, p. 86, pl. 13, fig. 18-19.
Diagnosis: Small, proximal, acavate, subspheroidal to ellipsoidal cyst with a circular equatorial section; the epicyst is slightly smaller than the hypocyst. It is characterized by the presence of thin, short intratabular processes that are connected distally, giving the surface a vermiculated to reticulate appearance. The paratabulation is of the gonyaulacoid type and corresponds to the formula: lpr. 4', 4a, 6 - 7", 6 - 7c, 6'", lp, 1"", 5s; it is indicated by parasutural furrows devoid of ornamentation. The archaeopyle is apical and intercalary of the (tAtl)a type with an operculum attached ventrally.
Dimensions: Holotype. Length: 40 µm, width: 30 µm. Variations: Length: 30-36 µm, width: 22-28 µm. Number of specimens measured: 18.
Material: > 40 specimens.
Description: The autophragm (1-2 µm thick) is smooth and bears numerous intratabular processes that are solid, rigid, flared at their distal end, of uniform height (2-4 µm), and regularly distributed. The arrangement of the hypocystal paraplates is partiform; the sulcal paraplates as, fm, is, and rs are discernible; the posterior sulcal paraplate is wider and subomegaform; the paracingulum (4 µm in average width) is very weakly laevorotatory or non-spiral. The operculum (12 µm long in Phototype) is composed of 4 apical paraplates, 4 anterior intercalary paraplates and 1 preapical paraplate.
Note: Microdinium mariae sp. nov. is characterized by its small, fused intratabular processes, its flared distal end, and the absence of ornamentation along the parasutures. Its ornamentation is reminiscent of Chiamydophorella (COOKSON and EISENACK ) DUXBURY (1983), but its assignment to the genus Mkrodinium is based on its partiform paratabulation type and especially its apical and intercalary archaeopyle. Although its size is smaller, it is very closely comparable to Moroccan specimens (see synonymy above). It slightly resembles Microdinium sp. 2 found in the Belgian Paleocene by SCHUMACKER-LAMBRY and CHATEAUNEUF (1976). Paratabulation in Fibradinium? densibaculaium (BELOW . 1987b) LENTIN and WILLIAMS (1989) is also indicated by a stop of ornamentation along parasutures but differs from the studied species by its smaller size and its shorter and denser ornamentation without distal connections. Eisenackia? santketum (BELOW , 1987b) LENTIN AND WILLIAMS (1989) has an irregular ornamentation and different from that of Microdinium mariae.
Stratigraphic distribution: Turnhout: -956 to -759.89 m, Upper Campanian - Late Upper Maastrichtian, Early Danian. SONCIN I and RAUSCHE R (1988) and in SONCIN I (1990), Upper Maastrichtian - Paleocene, Phosphate of Ouled Abdoun, Morocco.