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Leptodinium plagatum
Leptodinium? plagatum Dodekova 1994
Holotype Dodekova 1994 pl. XI, figs. 1-4,
Locus typicus: borehole R-3 Junak, depth 1695.5 m, Northeastern Bulgaria.
Stratum typcium: boundary Middle-Late Tithonian, Chitinoidella Zone, Tica Fm
Dimensions (in Ám). Holotype: length: 87, breadth: 83, length of apical horn: 7, height of sutural septa: 4. Range length: 60-98, breadth: 60-90; apical horn: 5-7.5, sutural septa, commonly: 1.5-4, with two exceptions: 11 (13 specimens measured).
Original Description: Dodekova 1994, p. 41-42
Proximate cyst, subspherical to polyhedral, acavate, with short noose-like apical horn. The horn is constructed by four trabeculae which are modifications of the apical sutural septa and which surrounded preapical plate/plates (pl. XI, fig. 7). The autophragm is smooth, hyaline. The sutural crests are commonly low, entire, with or without perforations in their bases. In some places the perforations are so large that the crests are transformed in trabeculae (pl. XI, figs. 10, 11). The trabeculae are developed mostly around the apex, the cingulum and the sulcus. If the trabeculae are broken, the sutures on the autophragm are unclear. Similar perforations created two characteristic ondulations of the lateral sutures in the antapical plate (pl. XI, fig. 6). The cingulum is relatively narrow. helicoidal. The sulcus is straight, short and wide, undivided (1pv only). The tabulation is gonyaulacacean, with formula: 1-2?pr, 4", 2a, 6", 6c, 5"", 1p, 1pv, 1"", 0s. The configuration of the tabulation pattern is demonstrated on Fig. 7. The apex ha.s relatively large plates 1" and 2", and smaller plates 3" and 4". The anterior intercalaries exist, a small triangular-- 1a and larger, rectangular to rhomboidal --2a. Rarely, in some specimens the plate 2a is equidimensional with apical plate 3". The precingular plate 6" is small five-sided. The antapical plate 1"" is asymmetrical, slightly inclined ventrally. The archeopyle is precingular, type 1P (3"). Operculum free. The intraspecific variability is expressed by differentiations in dimensions (till 30 Ám), in common form--- subspherical to polyhedral, the height and perforations of the sutural crests.
Remarks. Dodekova 1994, p. 41-42
L? plagatum sp. n. differs from all acavate species of the genus Leptodinium? by its construction of the apical horn, sutural trabeculae, details in the tabulation model and lack of any superficial ornamentation. L? plagatum sp. n. exists in large number specimens in all Tithonian (uppermost Middle -- Late Tithonian) dinocyst assemblages. It was published as Leptodinium sp. A by Dodekova in "Canyhob" et al. (1986a).
Occurrence. Borehole R-1 Dolni Dabnik (depth 2560.5 m, Late Tithonian, Pleven Fm.); R-1 Stezerovo (depth 1523 m, Late Tithonian, Kaspican Fm.); R-1 Gigen (depth 1644 m, Middle-Late Tithonian Kaspican Fm.); R-3 Brest (depth 1747 m, Middle-Late Tithonian, Kaspican Fm.); R-14 Grozdjovo (depth 2532 m, Middle-Late Tithonian, Tica Fm.); R-9 Bozvelijsko (depth 2302 m, Late Tithonian, Crassicollaria Zone, Tica Fm.); R-7 Sultanci (depth 1707-1765 m, Late Tithonian, Crassicollaria Zone, Tica Fm.); R-8 Sultanci (depth 1795-180.3 m, Late Tithonian, Crassicollaria Zone, Tica Fm.); R-11 Zitnica (depth 1713.8 m, boundary Late Titlloniall-Berriasian, Calpionella Zone, C. alpina Subzone, Tica Fm.); R-l Junak (Tica Fm., depth 1495-1578 m, Late Tithonian, Crassicollaria Zone; Himalayites (Micracanthoceras) fraudator (Zittel, 1868) -- H. (M.) microcanthus Subzone; depth 1636-1641 m, Middle Tithonian); R-3 Junak (depth 1688-1695.5 m, boundary Middle-Late Tithonian, Chitinoidella Zone, Tica Fm.), R-4 Junak (depth 1629-1638.7 m, Middle-Late Tithonian, Tica Fm.); outcrop Mahala Popska, Sevlievo, Zlatarica-Cerni Osam Fm., Late Tithonian, Paraulcocosphinctes transitorius Zone, Malbosiceras chaperi Subzone.
Holotype Dodekova 1994 pl. XI, figs. 1-4,
Locus typicus: borehole R-3 Junak, depth 1695.5 m, Northeastern Bulgaria.
Stratum typcium: boundary Middle-Late Tithonian, Chitinoidella Zone, Tica Fm
Dimensions (in Ám). Holotype: length: 87, breadth: 83, length of apical horn: 7, height of sutural septa: 4. Range length: 60-98, breadth: 60-90; apical horn: 5-7.5, sutural septa, commonly: 1.5-4, with two exceptions: 11 (13 specimens measured).
Original Description: Dodekova 1994, p. 41-42
Proximate cyst, subspherical to polyhedral, acavate, with short noose-like apical horn. The horn is constructed by four trabeculae which are modifications of the apical sutural septa and which surrounded preapical plate/plates (pl. XI, fig. 7). The autophragm is smooth, hyaline. The sutural crests are commonly low, entire, with or without perforations in their bases. In some places the perforations are so large that the crests are transformed in trabeculae (pl. XI, figs. 10, 11). The trabeculae are developed mostly around the apex, the cingulum and the sulcus. If the trabeculae are broken, the sutures on the autophragm are unclear. Similar perforations created two characteristic ondulations of the lateral sutures in the antapical plate (pl. XI, fig. 6). The cingulum is relatively narrow. helicoidal. The sulcus is straight, short and wide, undivided (1pv only). The tabulation is gonyaulacacean, with formula: 1-2?pr, 4", 2a, 6", 6c, 5"", 1p, 1pv, 1"", 0s. The configuration of the tabulation pattern is demonstrated on Fig. 7. The apex ha.s relatively large plates 1" and 2", and smaller plates 3" and 4". The anterior intercalaries exist, a small triangular-- 1a and larger, rectangular to rhomboidal --2a. Rarely, in some specimens the plate 2a is equidimensional with apical plate 3". The precingular plate 6" is small five-sided. The antapical plate 1"" is asymmetrical, slightly inclined ventrally. The archeopyle is precingular, type 1P (3"). Operculum free. The intraspecific variability is expressed by differentiations in dimensions (till 30 Ám), in common form--- subspherical to polyhedral, the height and perforations of the sutural crests.
Remarks. Dodekova 1994, p. 41-42
L? plagatum sp. n. differs from all acavate species of the genus Leptodinium? by its construction of the apical horn, sutural trabeculae, details in the tabulation model and lack of any superficial ornamentation. L? plagatum sp. n. exists in large number specimens in all Tithonian (uppermost Middle -- Late Tithonian) dinocyst assemblages. It was published as Leptodinium sp. A by Dodekova in "Canyhob" et al. (1986a).
Occurrence. Borehole R-1 Dolni Dabnik (depth 2560.5 m, Late Tithonian, Pleven Fm.); R-1 Stezerovo (depth 1523 m, Late Tithonian, Kaspican Fm.); R-1 Gigen (depth 1644 m, Middle-Late Tithonian Kaspican Fm.); R-3 Brest (depth 1747 m, Middle-Late Tithonian, Kaspican Fm.); R-14 Grozdjovo (depth 2532 m, Middle-Late Tithonian, Tica Fm.); R-9 Bozvelijsko (depth 2302 m, Late Tithonian, Crassicollaria Zone, Tica Fm.); R-7 Sultanci (depth 1707-1765 m, Late Tithonian, Crassicollaria Zone, Tica Fm.); R-8 Sultanci (depth 1795-180.3 m, Late Tithonian, Crassicollaria Zone, Tica Fm.); R-11 Zitnica (depth 1713.8 m, boundary Late Titlloniall-Berriasian, Calpionella Zone, C. alpina Subzone, Tica Fm.); R-l Junak (Tica Fm., depth 1495-1578 m, Late Tithonian, Crassicollaria Zone; Himalayites (Micracanthoceras) fraudator (Zittel, 1868) -- H. (M.) microcanthus Subzone; depth 1636-1641 m, Middle Tithonian); R-3 Junak (depth 1688-1695.5 m, boundary Middle-Late Tithonian, Chitinoidella Zone, Tica Fm.), R-4 Junak (depth 1629-1638.7 m, Middle-Late Tithonian, Tica Fm.); outcrop Mahala Popska, Sevlievo, Zlatarica-Cerni Osam Fm., Late Tithonian, Paraulcocosphinctes transitorius Zone, Malbosiceras chaperi Subzone.