Back
Caligodinium perforatum
Caligodinium perforatum, Guler et al., 2005, p.422,425, figs.4A–O.
Holotype: Guler et al., 2005, p.420–421, figs.5C–D.
Type locality: Estancia 25 de Mayo, Cerro Calafate, South of Lago Argentino, Austral Basin.
Type horizon: Sample VG6, 165 m. height; late Maastrichtian.
Stratigraphic ocurrence: Rare in sample VG3 and abundant in VG6.
Age: late Maastrichtian.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Guler et al., 2005]:
Diagnosis:
A large spheroidal to subspheroidal species of Caligodinium with a microfoveolate autophragm surrounded by a perforate flocculent calyptra. Antapical archeopyle; free simple triplacoid operculum.
Description:
Proximate, spheroidal to sub-spheroidal cyst. Autophragm about 1.5 µm thick, microfoveolate. A perforate adherent flocculent calyptra up to 3 µm thick surrounds the cyst; perforations varying in diameter.
Paratabulation expressed by the antapical archeopyle margin and short accesory sutures along the principal archeopyle margin. Operculum free, single-piece, triplacoid, occasionally in place and represented by two small antapical paraplates and one large postsulcal paraplate (figures 3.C; 5.K-L). The margin of the archeopyle and the accessory sutures reflect the presence of five postcingular paraplates and the two small sulcal paraplates rs and ls (figure 3.A-B). Other indication of paratabulation absent.
Dimensions:
Length of the cyst: 98 (111) 125 µm; width of the cyst: 100 (113) 120 µm (25 specimens measured).
Affinities:
Caligodinium perforatum sp. nov. Differs from other species of Caligodinium in having a foveolate to microfoveolate autophragm, a simple operculum and an adherent perforate calyptra giving a spongeous appearance. C. göeranii Slimani, 1994 is microfoveolate to microreticulate and lacks an outer flocculent calyptra. The autophragm is microreticulate in C . aceras Manum and Cookson, 1964, finely punctuate in C . amiculum Drugg, 1970, retirugulate in C . pychnum Biffi and Manum, 1988 and finely reticulate to punctoreticulate in C. Endoreticulum Stover and Hardenbol, 1994; all of these species have a variably developed veil-like calyptra. Based on descriptions and illustrations of C . amiculum , C . endoreticulum , C . pychnum and C. göeranii it is possible to observe separated opercular pieces. According to Manum and Williams (1995, p. 187), the opercular pieces in C. aceras remains together and have a weak tendency to break up. In the new species herein described none of the observed specimens showed separated opercular plates nor boundaries between the paraplates 1´´´´, 2´´´´ and ps. Morover, the new species is considerably larger in size than other species of Caligodinium .
Holotype: Guler et al., 2005, p.420–421, figs.5C–D.
Type locality: Estancia 25 de Mayo, Cerro Calafate, South of Lago Argentino, Austral Basin.
Type horizon: Sample VG6, 165 m. height; late Maastrichtian.
Stratigraphic ocurrence: Rare in sample VG3 and abundant in VG6.
Age: late Maastrichtian.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Guler et al., 2005]:
Diagnosis:
A large spheroidal to subspheroidal species of Caligodinium with a microfoveolate autophragm surrounded by a perforate flocculent calyptra. Antapical archeopyle; free simple triplacoid operculum.
Description:
Proximate, spheroidal to sub-spheroidal cyst. Autophragm about 1.5 µm thick, microfoveolate. A perforate adherent flocculent calyptra up to 3 µm thick surrounds the cyst; perforations varying in diameter.
Paratabulation expressed by the antapical archeopyle margin and short accesory sutures along the principal archeopyle margin. Operculum free, single-piece, triplacoid, occasionally in place and represented by two small antapical paraplates and one large postsulcal paraplate (figures 3.C; 5.K-L). The margin of the archeopyle and the accessory sutures reflect the presence of five postcingular paraplates and the two small sulcal paraplates rs and ls (figure 3.A-B). Other indication of paratabulation absent.
Dimensions:
Length of the cyst: 98 (111) 125 µm; width of the cyst: 100 (113) 120 µm (25 specimens measured).
Affinities:
Caligodinium perforatum sp. nov. Differs from other species of Caligodinium in having a foveolate to microfoveolate autophragm, a simple operculum and an adherent perforate calyptra giving a spongeous appearance. C. göeranii Slimani, 1994 is microfoveolate to microreticulate and lacks an outer flocculent calyptra. The autophragm is microreticulate in C . aceras Manum and Cookson, 1964, finely punctuate in C . amiculum Drugg, 1970, retirugulate in C . pychnum Biffi and Manum, 1988 and finely reticulate to punctoreticulate in C. Endoreticulum Stover and Hardenbol, 1994; all of these species have a variably developed veil-like calyptra. Based on descriptions and illustrations of C . amiculum , C . endoreticulum , C . pychnum and C. göeranii it is possible to observe separated opercular pieces. According to Manum and Williams (1995, p. 187), the opercular pieces in C. aceras remains together and have a weak tendency to break up. In the new species herein described none of the observed specimens showed separated opercular plates nor boundaries between the paraplates 1´´´´, 2´´´´ and ps. Morover, the new species is considerably larger in size than other species of Caligodinium .