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Erymnodinium delectabile
Erymnodinium delectabile (De Verteuil and Norris, 1992) Lentin et al., 1994
Originally Sumatradinium, subsequently, now Erymnodinium.
Holotype: de Verteuil and Norris, 1992, pl.9, figs.3-4
Locus typicus: St. Marys Formation, Little Cove Point Beds, 0.5 km south of Little Cove Point (the Ranch Club Section), west shore of Chesapeake Bay, Calvert County, Maryland
Stratum typicum: Late Miocene
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Erymnodinium delectabile (de Verteuil and Norris, 1992) Lentin et al., 1994. For description see genus. Size: length 75-95 µm, equatorial width 75-105 µm, sutural crests 5-8 µm.
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Original diagnosis: de Verteuil and Norris, 1992, p. 401: Sumatradinium? delectabilis
Large protoperidiniacean cysts, compressed dorsoventrally with a convex epicyst and two symmetrical antapical horns. Wall biphragmal; endophragm less than 0.5 Ám thick and psilate; periphragm, also thin, bears a fine, evenly distributed reticulum. Tabulation, defined by continuous sutural crests of even height and formed from the periphragm, is peridinioid 4', 3a, ?7", ?c, 5''', 0p, 2''''. Archeopyle hexa 2a, isodeltaform with reduced H3 and H5 sides, may be slightly displaced on the left dorsal epicyst.
Description: de Verteuil and Norris, 1992, p. 402
The epicyst is broadly convex in dorsoventral view with a rounded apex; it may have a low apical boss 5-7 Ám high formed by the confluence of the apical sutural crests. The hypocyst is smaller than the epicyst. It has straight or concave lateral sides and two more or less symmetrical, rounded antapical horns separated by a shallow to moderate depression approximately 3-6 Ám deep and about 10-25 Ám wide. The endophragm is less than 0.5 Ám thick, psilate and closely adpressed to the periphragm. The periphragm bears a fine, even and regular reticulum that appears typical of Sumatradinium. The lumina are roughly circular and 0.5-1.5 Ám in diameter; muri are 1 Ám in height. Sutural crests are composed of a closely adpressed, folded membrane, and some crests have narrow pandasutural canals at their base. The crests are psilate, sinuous in plan view, and of an even height between 5-8 Ám. Plate 4''' is broad and covers most of the dorsal hypocyst. Sutural crests are not developed around plate 2a. The combined effect is that on the dorsal surface the crests appear to be confined to the perimeter of the cyst. The cingulum is marked by two well developed cingular crests and is relatively narrow, while the sulcus is quite broad (upto 20 Ám), but indistinct.
Dimensions. Length, 75(83)95 Ám; holotype, 85 Ám. Equatorial width, 75(88)105 Ám; holotype 105 Ám. Sutural crests, 5-8 Ám. Twelve specimens measured.
Remarks: Lentin et al., 1994, p. 581
Occasional specimens of E. delectabile occur in the two highest samples (1085--1115 m) included in the Tortonian in the Evangeline H-98 well. The Scotian Shelf specimens show some differences from the type material as described by de Verteuil and Norris (1992). The surface ornamentation is generally an incomplete irregular reticulum and locally may be granular. Also, the sutural crests are not as consistently developed, especially on the paracingulum.
Originally Sumatradinium, subsequently, now Erymnodinium.
Holotype: de Verteuil and Norris, 1992, pl.9, figs.3-4
Locus typicus: St. Marys Formation, Little Cove Point Beds, 0.5 km south of Little Cove Point (the Ranch Club Section), west shore of Chesapeake Bay, Calvert County, Maryland
Stratum typicum: Late Miocene
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Erymnodinium delectabile (de Verteuil and Norris, 1992) Lentin et al., 1994. For description see genus. Size: length 75-95 µm, equatorial width 75-105 µm, sutural crests 5-8 µm.
--------------------------------------------------
Original diagnosis: de Verteuil and Norris, 1992, p. 401: Sumatradinium? delectabilis
Large protoperidiniacean cysts, compressed dorsoventrally with a convex epicyst and two symmetrical antapical horns. Wall biphragmal; endophragm less than 0.5 Ám thick and psilate; periphragm, also thin, bears a fine, evenly distributed reticulum. Tabulation, defined by continuous sutural crests of even height and formed from the periphragm, is peridinioid 4', 3a, ?7", ?c, 5''', 0p, 2''''. Archeopyle hexa 2a, isodeltaform with reduced H3 and H5 sides, may be slightly displaced on the left dorsal epicyst.
Description: de Verteuil and Norris, 1992, p. 402
The epicyst is broadly convex in dorsoventral view with a rounded apex; it may have a low apical boss 5-7 Ám high formed by the confluence of the apical sutural crests. The hypocyst is smaller than the epicyst. It has straight or concave lateral sides and two more or less symmetrical, rounded antapical horns separated by a shallow to moderate depression approximately 3-6 Ám deep and about 10-25 Ám wide. The endophragm is less than 0.5 Ám thick, psilate and closely adpressed to the periphragm. The periphragm bears a fine, even and regular reticulum that appears typical of Sumatradinium. The lumina are roughly circular and 0.5-1.5 Ám in diameter; muri are 1 Ám in height. Sutural crests are composed of a closely adpressed, folded membrane, and some crests have narrow pandasutural canals at their base. The crests are psilate, sinuous in plan view, and of an even height between 5-8 Ám. Plate 4''' is broad and covers most of the dorsal hypocyst. Sutural crests are not developed around plate 2a. The combined effect is that on the dorsal surface the crests appear to be confined to the perimeter of the cyst. The cingulum is marked by two well developed cingular crests and is relatively narrow, while the sulcus is quite broad (upto 20 Ám), but indistinct.
Dimensions. Length, 75(83)95 Ám; holotype, 85 Ám. Equatorial width, 75(88)105 Ám; holotype 105 Ám. Sutural crests, 5-8 Ám. Twelve specimens measured.
Remarks: Lentin et al., 1994, p. 581
Occasional specimens of E. delectabile occur in the two highest samples (1085--1115 m) included in the Tortonian in the Evangeline H-98 well. The Scotian Shelf specimens show some differences from the type material as described by de Verteuil and Norris (1992). The surface ornamentation is generally an incomplete irregular reticulum and locally may be granular. Also, the sutural crests are not as consistently developed, especially on the paracingulum.