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Deflandrea damasii
Deflandrea damasii (Lejeune-Carpentier, 1942) emend. Lejeune-Carpentier and Sarjeant, 1981
Originally Peridinium, subsequently Cooksoniella?, thirdly Palaeoperidinium, fourthly Deflandrea, fifthly (and now) Deflandrea?.
Lentin and Williams, 1985, questionably included this species in Deflandrea.
Holotype: Lejeune-Carpentier, 1942, fig.10; Lejeune-Carpentier and Sarjeant, 1981, pl.6, fig.3; text-fig.9a
Locus typicus: Flint of Craie de Spiennes (= Formatie van Gulpen of Felder, 1975), Mortiau quarry, Cuesmes, Belgium.
Stratum typicum: Upper Cretaceous (Senonian)
Age: Senonian
Emended Diagnosis: Lejeune-Carpentier and Sarjeant 1981, p. 16-18
Cornucavate to bicavate (or very narrowly circumcavate) cysts of small size, flattened dorsoventrally, with a broad-based, tapering and acute apical horn and two antapical horns, of shape and size similar to each other and to the apical horn, arising from the periblast. (The length of all homs approaches one-third of the length of the endoblast). Epitract of both periblast and endoblast convex, rounded anteriorly: hypotract slightly smaller, somewhat flattened posteriorly. Both layers of the phragma are thin and ornamented by a faint granulation or punctation. Strong ridges on the periblast demarcate a broad, almost planar to weakly laevorotatory cingulum. The sulcus and other elements of the paratabulation are less clearly defined by faint ridges. Paratabulation 4", 3a, 7", ?6c, 5"", 0p, 2"". Archaeopyle single-plate intercalary (type 1/1!, of broad-hexa type and formed by the loss of paraplate 2a.
Dimensions Holotype: overall length 64µm, length of apical horn 13µm, length of endoblast 38.5µm, length of antapical horns c. 13µm, overall breadth 39µm, breadth of endoblast 34µm. Range of Dimensions: Overall length 58-78µm, overall breadth 38-53µm, dorsoventral thickness 22-31µm.
Description: Lejeune-Carpentier and Sarjeant 1981, p. 16-18
The holotype and three of the other four figured specimens originally studied and illustrated by the first author (1942) were reexamined; the fifth specimen then figured, specimen CX11-188, could not be examined since the flint fragment in which it is contained has come free from its slide and requires remounting before it can be again studied. The holotype shows the archaeopyle and dorsal paratabulation well; specimen CX111-31 (illustrated by Lejeune-Carpentier, 1942, f1gs. 13-14 and herein, Text-figs. 9b-c) shows the full paratabulation best - and indeed, exceptionally well for a cavate cyst .
Apical paraplate 1" is approximately rhomboidal but broadest near its posterior margin and prolonged anteriorly to the horn tip; 2" and 4" are almost symmetrical, narrower than 1"; 3" is shorter and almost triangular. 2a is the largest of the anterior intercalary paraplates and of ""broad hexa"" type; the two other anterior intercalaries are similar in size and shape and much narrower. The largest of the precingulars are paraplates 2" and 6", both asymmetrically pentagonal and elongate; 3" and 5" are also asymmetrically pentagonal, but shorter: 4" is quadrate and laterally broad; 7" and 1" are the smallest of the series, again pentagonal and symmetrical about the junction of 1" with the sulcus. The largest of the postcingulars is the broad, symmetrical paraplate 3"", occupying the median dorsal portion of the hypotract; 2"" and 4"" are almost equally large and of similar shape; 5"" appears almost quadrate and 1"" appears similar. Two large paraplates, symmetrical in size, shape and position, occupy the antapex.
Characteristic features are the three acute, quite long and almost symmetrical horns; the meagre separation of the wall layers in lateral positions and at the antapex; and the very broad cingulum.
Remarks: Lejeune-Carpentier and Sarjeant 1981, p. 16-18
Our restudy makes clear the fact that this species is cavate, not proximate as hitherto supposed, and has a paratabulation and style of archaeopyle exactly typical of the genus Deflandrea, as emended by Lentin and Williams (1976, pp. 35-36). It is thus transferred to that genus with confidence.
The two most comparable species previously assigned to that genus are perhaps Deflandrea wardenensis Williams and Downie, 1966 and D. sibirica (Vozzhennikova, 1963) Lentin and Williams, 1976. However, the former species is distinguished by its less broad archaeopyle and both species by relatively poor expression of the paratabulation.
Originally Peridinium, subsequently Cooksoniella?, thirdly Palaeoperidinium, fourthly Deflandrea, fifthly (and now) Deflandrea?.
Lentin and Williams, 1985, questionably included this species in Deflandrea.
Holotype: Lejeune-Carpentier, 1942, fig.10; Lejeune-Carpentier and Sarjeant, 1981, pl.6, fig.3; text-fig.9a
Locus typicus: Flint of Craie de Spiennes (= Formatie van Gulpen of Felder, 1975), Mortiau quarry, Cuesmes, Belgium.
Stratum typicum: Upper Cretaceous (Senonian)
Age: Senonian
Emended Diagnosis: Lejeune-Carpentier and Sarjeant 1981, p. 16-18
Cornucavate to bicavate (or very narrowly circumcavate) cysts of small size, flattened dorsoventrally, with a broad-based, tapering and acute apical horn and two antapical horns, of shape and size similar to each other and to the apical horn, arising from the periblast. (The length of all homs approaches one-third of the length of the endoblast). Epitract of both periblast and endoblast convex, rounded anteriorly: hypotract slightly smaller, somewhat flattened posteriorly. Both layers of the phragma are thin and ornamented by a faint granulation or punctation. Strong ridges on the periblast demarcate a broad, almost planar to weakly laevorotatory cingulum. The sulcus and other elements of the paratabulation are less clearly defined by faint ridges. Paratabulation 4", 3a, 7", ?6c, 5"", 0p, 2"". Archaeopyle single-plate intercalary (type 1/1!, of broad-hexa type and formed by the loss of paraplate 2a.
Dimensions Holotype: overall length 64µm, length of apical horn 13µm, length of endoblast 38.5µm, length of antapical horns c. 13µm, overall breadth 39µm, breadth of endoblast 34µm. Range of Dimensions: Overall length 58-78µm, overall breadth 38-53µm, dorsoventral thickness 22-31µm.
Description: Lejeune-Carpentier and Sarjeant 1981, p. 16-18
The holotype and three of the other four figured specimens originally studied and illustrated by the first author (1942) were reexamined; the fifth specimen then figured, specimen CX11-188, could not be examined since the flint fragment in which it is contained has come free from its slide and requires remounting before it can be again studied. The holotype shows the archaeopyle and dorsal paratabulation well; specimen CX111-31 (illustrated by Lejeune-Carpentier, 1942, f1gs. 13-14 and herein, Text-figs. 9b-c) shows the full paratabulation best - and indeed, exceptionally well for a cavate cyst .
Apical paraplate 1" is approximately rhomboidal but broadest near its posterior margin and prolonged anteriorly to the horn tip; 2" and 4" are almost symmetrical, narrower than 1"; 3" is shorter and almost triangular. 2a is the largest of the anterior intercalary paraplates and of ""broad hexa"" type; the two other anterior intercalaries are similar in size and shape and much narrower. The largest of the precingulars are paraplates 2" and 6", both asymmetrically pentagonal and elongate; 3" and 5" are also asymmetrically pentagonal, but shorter: 4" is quadrate and laterally broad; 7" and 1" are the smallest of the series, again pentagonal and symmetrical about the junction of 1" with the sulcus. The largest of the postcingulars is the broad, symmetrical paraplate 3"", occupying the median dorsal portion of the hypotract; 2"" and 4"" are almost equally large and of similar shape; 5"" appears almost quadrate and 1"" appears similar. Two large paraplates, symmetrical in size, shape and position, occupy the antapex.
Characteristic features are the three acute, quite long and almost symmetrical horns; the meagre separation of the wall layers in lateral positions and at the antapex; and the very broad cingulum.
Remarks: Lejeune-Carpentier and Sarjeant 1981, p. 16-18
Our restudy makes clear the fact that this species is cavate, not proximate as hitherto supposed, and has a paratabulation and style of archaeopyle exactly typical of the genus Deflandrea, as emended by Lentin and Williams (1976, pp. 35-36). It is thus transferred to that genus with confidence.
The two most comparable species previously assigned to that genus are perhaps Deflandrea wardenensis Williams and Downie, 1966 and D. sibirica (Vozzhennikova, 1963) Lentin and Williams, 1976. However, the former species is distinguished by its less broad archaeopyle and both species by relatively poor expression of the paratabulation.