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Nannoceratopsis gracilis subsp. superba
Nannoceratopsis gracilis subsp. superba Bucefalo Palliani and Riding, 1998, p.172,174,177, fig.9, nos.1–6.
Holotype: Bucefalo Palliani and Riding, 1998, fig.9, no.1.
Age: late Toarcian–Aalenian.
Synonymy: 1996 Nannoceratopsis gracilis ALBERTI 1961 emend. EviTT 1962 emend. PRAUSS 1989.- POULSEN: 54, 55, pl. 37 figs. 1, 3, 5, 7, 8.
Holotype: Specimens W69.91 (1), England Finder coordinates N25-1 (Fig. 9 [1]).
Derivation of name: The subspecific epithet derives from the Latin superbus, meaning excellent or splendid, referring to the unusual holocavate cyst organisation of this subspecies.
Type locality and stratum: Wittnau borehole, Oberrhein, Southwest Germany (Fig. 1). Sample at 69.91 m core depth. Aalenian, L. opalinum ammonite Zone, P
torulosum ammonite Subzone.
Diagnosis: A subspecies of Nannoceratopsis gracilis with one or two antapical horns. The dorsal horn is the most prominent. The cyst is holocavate with an ectophragm supported by projections from the autophragm. The ectocoel is deep and prominent and is especially well-developed in the sagittal area.
Description: A subspecies of Nannoceratopsis gracilis with a prominent ectocoel. The ectophragm is thin, psilate and reticulate; the underlying autophragm is relatively thick and continuous. The autophragm is densely covered by numerous solid projections of variable length and thickness which support the ectophragm. The ectocoel is highest in the sagittal areas and the projections are frequently, longest at the distal point of the dorsal antapical hom. The ectophragm may be mechanically damaged as a result of its delicate nature. The distance between the projections is also variable. Of the two antapical horns, the dorsal hom is the most prominent.
Dimensions (µm): Holotype: length- 71.0; width- 48.8; mean height of ectophragm- 2.3.
Overall cyst length 73.3 (65 .5) 59.9; Overall cyst width 48.9 (44.9) 35.5; 26 specimens measured
Stratigraphical range: Nannoceratopsis gracilis subsp. superba n. subsp. is present in the Upper Toarcian (G. thouarsense ammonite Zone, P fallaciosum ammonite Subzone) to the Aalenian (L. opalinum ammonite Zone, L. comptum ammonite Subzone) of the Wittnau borehole, Oberrhein, Southwest Germany (Fig. 3). PouLSEN (1996, pl. 3 7) reported the subspecies from the Toarcian of Denmark.
Comments: Nannoceratopsis gracilis has an unequivocal holocavate cyst organisation (PRAUSS 1989, lLYINA et al. 1994, POULSEN 1996); this phenomenon was best illustrated by PIEL & EviTT (1980, pl. 3, fig. 2). The ectophragm and the suppporting structures of Nannoceratopsis gracilis are best observed in well-preserved material using a scanning electron microscope. The ectoceol in Nannoceratopsis gracilis is of a consistent low height and is often not visible using plain transmitted light (e. g. the holotype in ALBERTI 1961, pl. 7, fig. 17). The prominence of the ectocoel particularly in the sagittal areas in Nannoceratopsis gracilis subsp. superba n. subsp., however, serves to readily distinguish this subspecies. Nannoceratopsis pellucida and N spiculata are antapically cornucavate, however only Nannoceratopsis gracilis has a holocavate cyst organisation. Nannoceratopsis gracilis subsp. obsoletus has a corrugate to rugulate cyst wall.
Holotype: Bucefalo Palliani and Riding, 1998, fig.9, no.1.
Age: late Toarcian–Aalenian.
Synonymy: 1996 Nannoceratopsis gracilis ALBERTI 1961 emend. EviTT 1962 emend. PRAUSS 1989.- POULSEN: 54, 55, pl. 37 figs. 1, 3, 5, 7, 8.
Holotype: Specimens W69.91 (1), England Finder coordinates N25-1 (Fig. 9 [1]).
Derivation of name: The subspecific epithet derives from the Latin superbus, meaning excellent or splendid, referring to the unusual holocavate cyst organisation of this subspecies.
Type locality and stratum: Wittnau borehole, Oberrhein, Southwest Germany (Fig. 1). Sample at 69.91 m core depth. Aalenian, L. opalinum ammonite Zone, P
torulosum ammonite Subzone.
Diagnosis: A subspecies of Nannoceratopsis gracilis with one or two antapical horns. The dorsal horn is the most prominent. The cyst is holocavate with an ectophragm supported by projections from the autophragm. The ectocoel is deep and prominent and is especially well-developed in the sagittal area.
Description: A subspecies of Nannoceratopsis gracilis with a prominent ectocoel. The ectophragm is thin, psilate and reticulate; the underlying autophragm is relatively thick and continuous. The autophragm is densely covered by numerous solid projections of variable length and thickness which support the ectophragm. The ectocoel is highest in the sagittal areas and the projections are frequently, longest at the distal point of the dorsal antapical hom. The ectophragm may be mechanically damaged as a result of its delicate nature. The distance between the projections is also variable. Of the two antapical horns, the dorsal hom is the most prominent.
Dimensions (µm): Holotype: length- 71.0; width- 48.8; mean height of ectophragm- 2.3.
Overall cyst length 73.3 (65 .5) 59.9; Overall cyst width 48.9 (44.9) 35.5; 26 specimens measured
Stratigraphical range: Nannoceratopsis gracilis subsp. superba n. subsp. is present in the Upper Toarcian (G. thouarsense ammonite Zone, P fallaciosum ammonite Subzone) to the Aalenian (L. opalinum ammonite Zone, L. comptum ammonite Subzone) of the Wittnau borehole, Oberrhein, Southwest Germany (Fig. 3). PouLSEN (1996, pl. 3 7) reported the subspecies from the Toarcian of Denmark.
Comments: Nannoceratopsis gracilis has an unequivocal holocavate cyst organisation (PRAUSS 1989, lLYINA et al. 1994, POULSEN 1996); this phenomenon was best illustrated by PIEL & EviTT (1980, pl. 3, fig. 2). The ectophragm and the suppporting structures of Nannoceratopsis gracilis are best observed in well-preserved material using a scanning electron microscope. The ectoceol in Nannoceratopsis gracilis is of a consistent low height and is often not visible using plain transmitted light (e. g. the holotype in ALBERTI 1961, pl. 7, fig. 17). The prominence of the ectocoel particularly in the sagittal areas in Nannoceratopsis gracilis subsp. superba n. subsp., however, serves to readily distinguish this subspecies. Nannoceratopsis pellucida and N spiculata are antapically cornucavate, however only Nannoceratopsis gracilis has a holocavate cyst organisation. Nannoceratopsis gracilis subsp. obsoletus has a corrugate to rugulate cyst wall.