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Phanerodinium fourmarieri
Phanerodinium fourmarieri Lejeune-Carpentier, 1951, p.B311; text-fig.7. Emendation: Lejeune-Carpentier and Sarjeant, 1983, p.2, as Druggidium fourmarieri; Slimani and Louwye, 2011, p.48, as Phanerodinium fourmarieri.
Originally (and now) Phanerodinium subsequently Druggidium, thirdly ?Druggidium.
Holotype: Lejeune-Carpentier, 1951, text-fig.7; Streel et al., 1977, pl.2, fig.10.
Paratytpe: lejeune-Carpentier, 1983, text-fig. 1
Age: Senonian
Emended diagnosis (Lejeune-Carpentier & Sarjeant, 1983):
Cyst ovoidal to rounded-subpolygonal, of small relative size. Epitract rougly hemispheroidal, somewhat smaller than the hypotract; hypotract almost quadrate. Crests high and strong, vaginate to scalloped or phractate, higher on the hypotract (especially about the antapex) than on the epitract. Paratabulation 1pr, 4’, 1a, 6’’, ?6c, 6’’’, ?1p, 1’’’’, ?3s. Paraplate 2’’ is reduced in size, as a result of the presence of the asymmetrically situated anterior intercalary paraplate. Cingulum of moderate breath; sulcus relatively broad. Surface of phragma granulate. Archeopyle precingular (type 2P), formed by the loss of paraplates 2’’ and 3’’.
Paratype (here designated): specimens XIX-8 lodged in the collections of the Laboratoire de Paléontologie, Université de Liège, Belgium; figured by Lejeune-Carpentier, 1951, fig. 7 and herein, Pl. I :1, text-fig. 1
Emended diagnosis (Slimani & Louwye, 2011):
An ovoidal to rounded sub-polygonal Phanerodinium species characterized by its stiff, phractate or vaginate to scalloped sutural crests and by the absence of sutural crests between the adjacent precingular (3″) and cingular (4c) plates.
Modified description (Slimani & Louwye, 2011):
This small proximate dinoflagellate cyst is dorsoventrally slightly compressed and has an ovoidal to sub-polygonal shape. The hypocyst is rounded quadrate to pentagonal and represents about 3/4 of the total cyst length. The epicyst is hemispheroidal and shares the anterior part of the cyst equally with the cingulum. The autophragm is smooth to punctate with a maximum thickness of 0.5 to 1 μm. The tabulation is that of the genus Phanerodinium, and is reflected on the dorsal surface by strong, phractate or vaginate to scalloped sutural crests, which are higher on the hypocyst. The ventral surface lacks sutures. The crests might be two times higher at their confluences, prodrucing gonal distal extentions. The reconstructed tabulation consists of 4 precingular (2″–5″), 3 cingular (3c– 5c), 4 postcingular (2″′–5″′), an antapical (1″″) plates and a posterior intercalary (1p) plate. The apical plates are undistinguishable. The suture between the precingular (3″) and adjacent cingular (4c) plates is absent. The sulcal plates and the plates adjacent to it are not expressed by raised features. The archeopyle is precingular of type P. It is located closely to the right of a dorsal longitudinal median line and is formed by the release of the precingular plate 4″. The operculum is free.
Discussion (Slimani & Louwye, 2011):
Our specimens of Phanerodinium fourmarieri and also those recorded from Belgium as Phanerodinium sp. cf. Druggidium fourmarieri by Slimani (1994, 1995, 2000) and Slimani et al. (2011) are comparable to the type material described by Lejeune-Carpentier (1951). Phanerodinium fourmarieri differs from all the other Phanerodinium species by its characteristic phractate or vaginate to scalloped sutural crests and by the typical absence of sutural crests between the adjacent precingular (3″) and cingular (4c) plates. This species was originally considered as a species of Phanerodinium Deflandre, 1937, but was reassigned later to the genus Druggidium Habib, 1973 by Lejeune-Carpentier and Sarjeant (1983), based on their re-examination of the type material. In our opinion, this reassignment was based on an erroneous interpretation of the tabulation of poorly preserved specimens observed in a flint matrix. The dorsal surface of the holotype (Lejeune-Carpentier and Sarjeant, 1983, text-fig. 1, pl. 1, fig. 1) shows two postcingular plates (3″′, 4″′) and a very broad cingulum with its invaginations clearly developed laterally and a high posterior crest. However, the plates interpreted by the authors on the illustration of the holotype (text-fig. 1), as precingular 2″ and apical (1’) represent respectively the cingular plate (4c) and the precingular plate (3″). The real archeopyle is then of type P and is smaller than interpreted by the authors (text-fig. 1); it is visible as the clear square at the right part of the apex of the holotype (pl. 1, fig. 1). The paratype (Lejeune-Carpentier and Sarjeant, 1983, text-fig. 2, pl. 1, fig. 2) is not oriented in apical view as indicated by the authors (text-fig. 2), but in dorsal view and oriented transversally with the apex at the left side. It shows, as does the 48 H. Slimani, S. Louwye / Review of Palaeobotany and Palynology 168 (2011) 41–50 holotype, a small precingular archeopyle and a broad cingulum characterised by the absence of sutural crests between the adjacent precingular (3″) and cingular (4c) plates. Consequently, there is no indication of apical, anterior intercalary and precingular (5″, 6″) plates as indicated by Lejeune-Carpentier and Sarjeant (1983, text-fig. 2) on the illustration of the paratype. According to the latter authors (p. 3), the ventral surface “could not be determined with sufficient precision for full illustration”. This means that the ventral surface is in fact devoid of sutural features, as observed on our specimens. The morphological characters displayed by our specimens, and the new interpretation of the type material figured by Lejeune-Carpentier and Sarjeant (1983), are distinctly different from those known for the genus Druggidium, and justify the transfer of this species back into Phanerodinium.
Dimensions (Slimani & Louwye, 2011):
Range: overall length 18(22)26 μm, overall width 18 (21)26 μm, maximal high of crests 2 μm. Number of specimens measured: 10
Stratigraphic occurrence (Slimani & Louwye, 2011): Upper Maastrichtian of Hallembaye (Maastricht area) (Lejeune-Carpentier, 1951); Turonian, Pas-De-Calais (France) (Foucher, 1974); Lower–Upper Maastrichtian of Mons (southern Belgium) (Foucher and Robaszynski, 1977); Upper Maastrichtian of Hallembaye (Maastricht area) and Lower–Upper Maastrichtian of Turnhout (northern Belgium) (Slimani, 1994, 1995, 2000); Upper Campanian–Upper Maastrichtian of Meer (Slimani et al., 2011), northern Belgium.
Originally (and now) Phanerodinium subsequently Druggidium, thirdly ?Druggidium.
Holotype: Lejeune-Carpentier, 1951, text-fig.7; Streel et al., 1977, pl.2, fig.10.
Paratytpe: lejeune-Carpentier, 1983, text-fig. 1
Age: Senonian
Emended diagnosis (Lejeune-Carpentier & Sarjeant, 1983):
Cyst ovoidal to rounded-subpolygonal, of small relative size. Epitract rougly hemispheroidal, somewhat smaller than the hypotract; hypotract almost quadrate. Crests high and strong, vaginate to scalloped or phractate, higher on the hypotract (especially about the antapex) than on the epitract. Paratabulation 1pr, 4’, 1a, 6’’, ?6c, 6’’’, ?1p, 1’’’’, ?3s. Paraplate 2’’ is reduced in size, as a result of the presence of the asymmetrically situated anterior intercalary paraplate. Cingulum of moderate breath; sulcus relatively broad. Surface of phragma granulate. Archeopyle precingular (type 2P), formed by the loss of paraplates 2’’ and 3’’.
Paratype (here designated): specimens XIX-8 lodged in the collections of the Laboratoire de Paléontologie, Université de Liège, Belgium; figured by Lejeune-Carpentier, 1951, fig. 7 and herein, Pl. I :1, text-fig. 1
Emended diagnosis (Slimani & Louwye, 2011):
An ovoidal to rounded sub-polygonal Phanerodinium species characterized by its stiff, phractate or vaginate to scalloped sutural crests and by the absence of sutural crests between the adjacent precingular (3″) and cingular (4c) plates.
Modified description (Slimani & Louwye, 2011):
This small proximate dinoflagellate cyst is dorsoventrally slightly compressed and has an ovoidal to sub-polygonal shape. The hypocyst is rounded quadrate to pentagonal and represents about 3/4 of the total cyst length. The epicyst is hemispheroidal and shares the anterior part of the cyst equally with the cingulum. The autophragm is smooth to punctate with a maximum thickness of 0.5 to 1 μm. The tabulation is that of the genus Phanerodinium, and is reflected on the dorsal surface by strong, phractate or vaginate to scalloped sutural crests, which are higher on the hypocyst. The ventral surface lacks sutures. The crests might be two times higher at their confluences, prodrucing gonal distal extentions. The reconstructed tabulation consists of 4 precingular (2″–5″), 3 cingular (3c– 5c), 4 postcingular (2″′–5″′), an antapical (1″″) plates and a posterior intercalary (1p) plate. The apical plates are undistinguishable. The suture between the precingular (3″) and adjacent cingular (4c) plates is absent. The sulcal plates and the plates adjacent to it are not expressed by raised features. The archeopyle is precingular of type P. It is located closely to the right of a dorsal longitudinal median line and is formed by the release of the precingular plate 4″. The operculum is free.
Discussion (Slimani & Louwye, 2011):
Our specimens of Phanerodinium fourmarieri and also those recorded from Belgium as Phanerodinium sp. cf. Druggidium fourmarieri by Slimani (1994, 1995, 2000) and Slimani et al. (2011) are comparable to the type material described by Lejeune-Carpentier (1951). Phanerodinium fourmarieri differs from all the other Phanerodinium species by its characteristic phractate or vaginate to scalloped sutural crests and by the typical absence of sutural crests between the adjacent precingular (3″) and cingular (4c) plates. This species was originally considered as a species of Phanerodinium Deflandre, 1937, but was reassigned later to the genus Druggidium Habib, 1973 by Lejeune-Carpentier and Sarjeant (1983), based on their re-examination of the type material. In our opinion, this reassignment was based on an erroneous interpretation of the tabulation of poorly preserved specimens observed in a flint matrix. The dorsal surface of the holotype (Lejeune-Carpentier and Sarjeant, 1983, text-fig. 1, pl. 1, fig. 1) shows two postcingular plates (3″′, 4″′) and a very broad cingulum with its invaginations clearly developed laterally and a high posterior crest. However, the plates interpreted by the authors on the illustration of the holotype (text-fig. 1), as precingular 2″ and apical (1’) represent respectively the cingular plate (4c) and the precingular plate (3″). The real archeopyle is then of type P and is smaller than interpreted by the authors (text-fig. 1); it is visible as the clear square at the right part of the apex of the holotype (pl. 1, fig. 1). The paratype (Lejeune-Carpentier and Sarjeant, 1983, text-fig. 2, pl. 1, fig. 2) is not oriented in apical view as indicated by the authors (text-fig. 2), but in dorsal view and oriented transversally with the apex at the left side. It shows, as does the 48 H. Slimani, S. Louwye / Review of Palaeobotany and Palynology 168 (2011) 41–50 holotype, a small precingular archeopyle and a broad cingulum characterised by the absence of sutural crests between the adjacent precingular (3″) and cingular (4c) plates. Consequently, there is no indication of apical, anterior intercalary and precingular (5″, 6″) plates as indicated by Lejeune-Carpentier and Sarjeant (1983, text-fig. 2) on the illustration of the paratype. According to the latter authors (p. 3), the ventral surface “could not be determined with sufficient precision for full illustration”. This means that the ventral surface is in fact devoid of sutural features, as observed on our specimens. The morphological characters displayed by our specimens, and the new interpretation of the type material figured by Lejeune-Carpentier and Sarjeant (1983), are distinctly different from those known for the genus Druggidium, and justify the transfer of this species back into Phanerodinium.
Dimensions (Slimani & Louwye, 2011):
Range: overall length 18(22)26 μm, overall width 18 (21)26 μm, maximal high of crests 2 μm. Number of specimens measured: 10
Stratigraphic occurrence (Slimani & Louwye, 2011): Upper Maastrichtian of Hallembaye (Maastricht area) (Lejeune-Carpentier, 1951); Turonian, Pas-De-Calais (France) (Foucher, 1974); Lower–Upper Maastrichtian of Mons (southern Belgium) (Foucher and Robaszynski, 1977); Upper Maastrichtian of Hallembaye (Maastricht area) and Lower–Upper Maastrichtian of Turnhout (northern Belgium) (Slimani, 1994, 1995, 2000); Upper Campanian–Upper Maastrichtian of Meer (Slimani et al., 2011), northern Belgium.