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Endoceratium ludbrookiae

Endoceratium ludbrookiae (Cookson and Eisenack, 1958) Loeblich and Loeblich, 1966; emend. Morgan, 1980

Originally Ceratocystidiopsis, subsequently Pseudoceratium, thirdly (and now) Endoceratium.
This combination was not validly published in Vozzhennikova, 1965, since that author did not fully reference the basionym.
Helby, 1987, retained this species in Pseudoceratium Gocht, 1957. Lentin and Williams, 1989, retained it in Endoceratium.

Holotype: Cookson and Eisenack, 1958, pl.5, fig.7
Paratype: Cookson and Eisenack, 1958
Locus typicus: Cootabarlow, S Australia
Stratum typicum: Albian

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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.

Endoceratium ludbrookiae (Cookson and Eisenack, 1958) Loeblich Jr. and Loeblich III, 1966, emend. Morgan, 1980. The pericyst is convex triangular, with a rather blunt, obliquely directed apical horn and two somewhat unequal, antapical horns with more pointed apices. The endocyst is also convex triangular and finely granular, the pericyst is smooth. Size:pericyst length 142-190 µm, width 85-109 µm, apical horn 38-62 µm, endocyst length 90 µm in holotype.
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Original description: Cookson and Eisenack, 1958, p. 53: Ceratocystidiopsis ludbrookii
Theca approximating in outline to an isoceles triangle with convex sides, a rather blunt obliquelydirected apical horn and two divergent and somewhat unequal antapical horns with more pointed apices. The internal capsule is sub-trianguilar with a flat base, convex sides and a blunt apex and is seperated from the outer membrane by a space of cariable width. The wall of the internal body is finely granualr, that of the outer membrane smooth. The apical region of the theca may become completely detached along an irregular line that extends obliquely across ist upper portion.

Emended description: Morgan, 1980, p. 23
Cyst broadly subtriangular, with convex sides; periphragm extended to form a strong broad blunt-ended apical horn, one strong broad blunt-ended antapical horn and two lateral horns, the one on the same side as the large antapical horn a subtle bulge, the other a strong, broad, blunt-ended horn, directed antapically; cingulum usually seen as a pair of ridges on the periphragm; periphragm may bear low reticulate ornament: endophragm broadly triangular in outline with convex sides, the three blunt apices correspond to the three major horns of the periphragm, or with subcircular ambitus: periphragm closely appressed to the endophragm over most of the dorsal and ventral surfaces separated around the periphery to form an ambital pericoel; complex relationship between the two phragms in the dorsal and ventral areas shows a fine pseudoreticulate pattern in optical section, and marks some tabulation indistinctly: tabulation gonyaulacean, 4', 6", 5''', 1p, 1''''; strongly offset cingulum beneath the large 5" plate characteristic archeopyle apical, operculum free.
Comments: The many specimens examined in the present study show considerable variation. Most are nontabulate, except for the pericingulum parasutures which can be seen most clearly on the lateral horns. Rare specimens show complete tabulation, as in plate 11, figures 1 5, showing the paracingulum offset almost to the antapex (plate 11, figure 2). The resulting large 5" paraplate is most striking. Periphragm surface reticulation, shown in section in plate 10, figures 18-19 has only been seen in Western Australian examples, and may warrant separation as a separate species.

Affinities:
Cookson and Eisneack, 1958, p. 54: Ceratocystidiopsis ludbrookii
Ceratocystidiopsis ludbrookii agrees in general features with C. molesta Defl. from the French Senonian, but differs from it both in size and shape.
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