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Dapcodinium inornatum
Dapcodinium inornatum (Morgenroth, 1970) Dörhöfer and Davies, 1980
Now Maturodinium. Originally (and now) Maturodinium, subsequently Dapcodinium.
Lentin and Williams, 1985, retained this species in Maturodinium Morgenroth, 1970.
Holotype: Morgenroth, 1970, pl.13, figs.5-6 (plate caption transposed with that of pl.12, fig.6); Fensome et al., 1993, p.1237, figs.1-2
Paratypes: Morgenroth, 1970
Locus typicus: Stichkanal Hildesheim, east of Luhnde, Germany
Stratum typicum: Late Pliensbachian
Original diagnosis: Morgenroth, 1970, p.354: Maturodinium inornatum
Test ovoidal; epitract shorter than hypotract. Wall + 1 Á thick; surface of test strongly granular. Reflected tabulation: 4", ?4a, 7", 7c, 6""", 1p, 1"""". Sutures between plate equivalents marked by absence of granulation. Cingulum slightly laevo-rotatory. Sulcus extends onto the epitract and broadens towards antapex. Apical horn minute. Archeopyle type: (A)a + ?4I.
Original description: Morgenroth, 1970, p.354-355: Maturodinium inornatum
The surface of the ovoidal test is strongly granular. The epitract is smaller than the hypotract ([Morgenroth, 1970] pl. 13, fig. 5). The sutures between the reflected plates are marked by absence of granulation ([Morgenroth, 1970] pl. 13, fig. 5).
Four apical plates are reflected ([Morgenroth, 1970] pl. 13, figs. 6,7). Plate 1" is elongate and occupies the anterior prolongation of the sulcus. In front of 1" lies the small ?hexagonal plate 3". The pentagonal plates 2" and 4" are symmetrically arranged on both sides of 1" and 3". A minute apical "norn rises from the junction between the apical plates ([Morgenroth, 1970] pl. 13, fig. 7). None of the specimens available shows anterior intercalary plates in place. However, inside one specimen two isolated pentagonal anterior intercalary plates have been observed. Moreover, the shape of the archeopyle compared with the outline of the apical plates strongly suggests the presence of four pentagonal intercalary plate equivalents, so that the reflected plate arrangement would be very similar, if not identical with the plates reflected on the epitract of Mancodinium. Above the cingulum seven pentagonal precingular plates are reflected. The cingulum is broad and laevo-rotatory, its two ends differing in anterior-posterior position by about one half of its breadth. It is subdivided into seven cingular plate equivalents of which 1c and 7c are reduced. Six postcingular plates are reflected, 1""" and 2""" being smaller than the other plates. One trapezoidal posterior intercalary plate is reflected below 1""". The slightly intruding sulcus extends onto the epitract. It broadens towards the antapex.
All specimens available show an archeopyle. An opercular piece consisting of the four apical plates is attached ventrally to the sulcal region. The reflected anterior intercalary plates are discarded on all specimens. The discovery of two isolated pentagonal intercalary plates inside one specimen leads to the conclusion that the anterior intercalary plates are thrown off separately, so that the operculum would be composed of five pieces: one opercular piece consisting of the four apical plates and four opercular pieces each corresponding to one anterior intercalary plate (Archeopyle type: (A)a + ?4I).
Size: Holotype: length 37 µm, breadth 30 µm. Range of 10 specimens: length 37(38)40 µm, breadth 30(31)33 µm.
Now Maturodinium. Originally (and now) Maturodinium, subsequently Dapcodinium.
Lentin and Williams, 1985, retained this species in Maturodinium Morgenroth, 1970.
Holotype: Morgenroth, 1970, pl.13, figs.5-6 (plate caption transposed with that of pl.12, fig.6); Fensome et al., 1993, p.1237, figs.1-2
Paratypes: Morgenroth, 1970
Locus typicus: Stichkanal Hildesheim, east of Luhnde, Germany
Stratum typicum: Late Pliensbachian
Original diagnosis: Morgenroth, 1970, p.354: Maturodinium inornatum
Test ovoidal; epitract shorter than hypotract. Wall + 1 Á thick; surface of test strongly granular. Reflected tabulation: 4", ?4a, 7", 7c, 6""", 1p, 1"""". Sutures between plate equivalents marked by absence of granulation. Cingulum slightly laevo-rotatory. Sulcus extends onto the epitract and broadens towards antapex. Apical horn minute. Archeopyle type: (A)a + ?4I.
Original description: Morgenroth, 1970, p.354-355: Maturodinium inornatum
The surface of the ovoidal test is strongly granular. The epitract is smaller than the hypotract ([Morgenroth, 1970] pl. 13, fig. 5). The sutures between the reflected plates are marked by absence of granulation ([Morgenroth, 1970] pl. 13, fig. 5).
Four apical plates are reflected ([Morgenroth, 1970] pl. 13, figs. 6,7). Plate 1" is elongate and occupies the anterior prolongation of the sulcus. In front of 1" lies the small ?hexagonal plate 3". The pentagonal plates 2" and 4" are symmetrically arranged on both sides of 1" and 3". A minute apical "norn rises from the junction between the apical plates ([Morgenroth, 1970] pl. 13, fig. 7). None of the specimens available shows anterior intercalary plates in place. However, inside one specimen two isolated pentagonal anterior intercalary plates have been observed. Moreover, the shape of the archeopyle compared with the outline of the apical plates strongly suggests the presence of four pentagonal intercalary plate equivalents, so that the reflected plate arrangement would be very similar, if not identical with the plates reflected on the epitract of Mancodinium. Above the cingulum seven pentagonal precingular plates are reflected. The cingulum is broad and laevo-rotatory, its two ends differing in anterior-posterior position by about one half of its breadth. It is subdivided into seven cingular plate equivalents of which 1c and 7c are reduced. Six postcingular plates are reflected, 1""" and 2""" being smaller than the other plates. One trapezoidal posterior intercalary plate is reflected below 1""". The slightly intruding sulcus extends onto the epitract. It broadens towards the antapex.
All specimens available show an archeopyle. An opercular piece consisting of the four apical plates is attached ventrally to the sulcal region. The reflected anterior intercalary plates are discarded on all specimens. The discovery of two isolated pentagonal intercalary plates inside one specimen leads to the conclusion that the anterior intercalary plates are thrown off separately, so that the operculum would be composed of five pieces: one opercular piece consisting of the four apical plates and four opercular pieces each corresponding to one anterior intercalary plate (Archeopyle type: (A)a + ?4I).
Size: Holotype: length 37 µm, breadth 30 µm. Range of 10 specimens: length 37(38)40 µm, breadth 30(31)33 µm.