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Mendicodinium groenlandicum
Mendicodinium groenlandicum (Pocock and Sarjeant, 1972) Davey, 1979
Originally Thuledinium, subsequently (and now) Mendicodinium.
Tax. sr. synonym of Mendicodinium woodhamense Drugg, 1978, according to Riley and Fenton, 1982.
Holotype: Pocock and Sarjeant, 1972, pl. 2, fig.1, text-fig. 2
Paratypes: Pocock and Sarjeant, 1972
Locus typicus: Jameson Land, E Greenland
Stratum typicum: Middle Callovian
Original description: Pocock and Sarjeant, 1972, p. 352-353: Thuledinium groenlandicum
Diagnosis: Vesicle ovoidal to almost ellipsoidal. Both the apical and antapical caps are small; the two sections comprising the main body are much larger. Both caps have rounded flanks and somewhat angular ends, the angular ends corresponding to the positions of the two sutures separating the two main sections of the vesicle; at this point, both caps and main sections are frequently slightly torn. The wall is thin and appears to be composed of a single layer. Its surface lacks major ornament but may exhibit slight pitting or punctae; it is frequently folded to a greater or lesser extent and may display marks formed by pressure of mineral grains.
Dimensions: Holotype: Length 108 µm, breadth 78.5 µm. Range(65 specimens): Length 91.5-124 µm, breadth 65-94 µm.
Poulsen 1996, p. 84-85
Mendicodinium groenlandicum (Pocock & Sarjeant 1972) Davey 1979, Pl. 28, Figs. 1-6
Remarks. Most of the M. groenlandicum specimens from the latest Jurassic in Denmark contained a reduction body which resembles a small piece of amorphous material, and may (according to Rex Harland, oral commun., 1990) be relict cytoplasm, the presence of which would suggest that the cysts failed to excyst. The archeopyle in these specimens appears not to have been developed, although a beginning development may be seen (e.g. Pl. 28, Fig 1). This partially developed archeopyle may be related to the palynological preparation process. SEM studies of the wall of specimens from the Early Oxfordian of east Greenland and of those recorded from the latest Jurassic in Denmark show no significant differences. Therefore, is it believed that the specimens recorded from Denmark belong to M. groenlandicum.
Recorded occurrences.
Denmark Mancodinium semitabulatum Subzone, Mancodinium semitabulatum-Gochteodinia villosa Zone, Endoscrinium pharo Subzone.
Poland: Bimammatum-Scythicus Zones.
Originally Thuledinium, subsequently (and now) Mendicodinium.
Tax. sr. synonym of Mendicodinium woodhamense Drugg, 1978, according to Riley and Fenton, 1982.
Holotype: Pocock and Sarjeant, 1972, pl. 2, fig.1, text-fig. 2
Paratypes: Pocock and Sarjeant, 1972
Locus typicus: Jameson Land, E Greenland
Stratum typicum: Middle Callovian
Original description: Pocock and Sarjeant, 1972, p. 352-353: Thuledinium groenlandicum
Diagnosis: Vesicle ovoidal to almost ellipsoidal. Both the apical and antapical caps are small; the two sections comprising the main body are much larger. Both caps have rounded flanks and somewhat angular ends, the angular ends corresponding to the positions of the two sutures separating the two main sections of the vesicle; at this point, both caps and main sections are frequently slightly torn. The wall is thin and appears to be composed of a single layer. Its surface lacks major ornament but may exhibit slight pitting or punctae; it is frequently folded to a greater or lesser extent and may display marks formed by pressure of mineral grains.
Dimensions: Holotype: Length 108 µm, breadth 78.5 µm. Range(65 specimens): Length 91.5-124 µm, breadth 65-94 µm.
Poulsen 1996, p. 84-85
Mendicodinium groenlandicum (Pocock & Sarjeant 1972) Davey 1979, Pl. 28, Figs. 1-6
Remarks. Most of the M. groenlandicum specimens from the latest Jurassic in Denmark contained a reduction body which resembles a small piece of amorphous material, and may (according to Rex Harland, oral commun., 1990) be relict cytoplasm, the presence of which would suggest that the cysts failed to excyst. The archeopyle in these specimens appears not to have been developed, although a beginning development may be seen (e.g. Pl. 28, Fig 1). This partially developed archeopyle may be related to the palynological preparation process. SEM studies of the wall of specimens from the Early Oxfordian of east Greenland and of those recorded from the latest Jurassic in Denmark show no significant differences. Therefore, is it believed that the specimens recorded from Denmark belong to M. groenlandicum.
Recorded occurrences.
Denmark Mancodinium semitabulatum Subzone, Mancodinium semitabulatum-Gochteodinia villosa Zone, Endoscrinium pharo Subzone.
Poland: Bimammatum-Scythicus Zones.