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Druggidium ornatum
From Fensome et al., 2019:
Duxbury, 2019, p.188, pl.3, figs.8–9,16,20. Holotype: Duxbury, 2019, pl.3, figs.16,20. Age: late Barremian.
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Original description Duxbury, 2019:
Holotype: Plate 3, Figures 16, 20
Type Locality: Heslerton No. 2 at 24.00 m (core chip), late Barremian age. Holotype: E.F. G46.0.
Derivation of Name: From the Latin ornatus, decorated – in reference to the surface ornament.
Diagnosis: A small, elongate ovoidal species with tabulation apparently typical for the genus, sometimes expressed as low surface ridges but indistinct. A broad, distinct cingulum is very high on the cyst, reflecting a squat epicyst and a much longer hypocyst. Surface ornament invariably present varying from fine granulation over the entire cyst to sparser distribution with isolated areas devoid of ornament; lineation of the surface ornament sometimes observed. The archeopyle includes two precingular plates which can remain adherent and which may be entirely smooth.
Dimensions: Holotype: Length - 41 μm. Width - 25 μm
Overall: Length - 41 (39) 35 μm; Width - 25 (25) 23 μm.
Specimens Measured: 4.
Remarks: This is a rare species, occurring sporadically in the present study between the 29.85 m and 19.00 m samples in Heslerton No. 2 (late Barremian). It is considered possibly conspecific with that recorded by Harding (1986, Plate 3, Figure 15) as Druggidium cf. apicopaucicum Habib 1973, although Harding (op. cit.) did not comment on his taxon. The species closest to D. ornatum n. sp. appears to be Druggidium apicopaucicum Habib 1973, but the indistinct tabulation and surface ornament of the former clearly distinguish it. Also, although Habib (op. cit., p. 52) gave a range of Berriasian to Barremian for D. apicopaucicum, Habib and Drugg (1983, p. 629) quote an age range of early Valanginian to late Hauterivian, significantly older than anything analysed here.
Millioud’s illustrations of the type material of Druggidium deflandrei (Millioud 1969) Habib 1973 (Millioud, op. cit.; Plate 2, Figures 5-7) bear superficial resemblance to D. ornatum, although the detailed morphology is difficult to assess. However, Millioud (op. cit., p. 429) stated, “sutures low, probably perforate. Wall finely vacuolar and sometimes scabrate”, which is very similar to Habib’s interpretation of this species (Habib 1973) and his description (op. cit., p. 52), “Tract surface alveolate; alveolae commonly restricted to zones near the plate boundaries”. In contrast, Below’s illustrations (1987, Plate 17, Figures 7-15) appear to show a different species entirely, squat and with denticulate crests. His emendation of this species (Below 1987, p. 58, as Raphidodinium deflandrei) is therefore rejected here.
Duxbury, 2019, p.188, pl.3, figs.8–9,16,20. Holotype: Duxbury, 2019, pl.3, figs.16,20. Age: late Barremian.
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Original description Duxbury, 2019:
Holotype: Plate 3, Figures 16, 20
Type Locality: Heslerton No. 2 at 24.00 m (core chip), late Barremian age. Holotype: E.F. G46.0.
Derivation of Name: From the Latin ornatus, decorated – in reference to the surface ornament.
Diagnosis: A small, elongate ovoidal species with tabulation apparently typical for the genus, sometimes expressed as low surface ridges but indistinct. A broad, distinct cingulum is very high on the cyst, reflecting a squat epicyst and a much longer hypocyst. Surface ornament invariably present varying from fine granulation over the entire cyst to sparser distribution with isolated areas devoid of ornament; lineation of the surface ornament sometimes observed. The archeopyle includes two precingular plates which can remain adherent and which may be entirely smooth.
Dimensions: Holotype: Length - 41 μm. Width - 25 μm
Overall: Length - 41 (39) 35 μm; Width - 25 (25) 23 μm.
Specimens Measured: 4.
Remarks: This is a rare species, occurring sporadically in the present study between the 29.85 m and 19.00 m samples in Heslerton No. 2 (late Barremian). It is considered possibly conspecific with that recorded by Harding (1986, Plate 3, Figure 15) as Druggidium cf. apicopaucicum Habib 1973, although Harding (op. cit.) did not comment on his taxon. The species closest to D. ornatum n. sp. appears to be Druggidium apicopaucicum Habib 1973, but the indistinct tabulation and surface ornament of the former clearly distinguish it. Also, although Habib (op. cit., p. 52) gave a range of Berriasian to Barremian for D. apicopaucicum, Habib and Drugg (1983, p. 629) quote an age range of early Valanginian to late Hauterivian, significantly older than anything analysed here.
Millioud’s illustrations of the type material of Druggidium deflandrei (Millioud 1969) Habib 1973 (Millioud, op. cit.; Plate 2, Figures 5-7) bear superficial resemblance to D. ornatum, although the detailed morphology is difficult to assess. However, Millioud (op. cit., p. 429) stated, “sutures low, probably perforate. Wall finely vacuolar and sometimes scabrate”, which is very similar to Habib’s interpretation of this species (Habib 1973) and his description (op. cit., p. 52), “Tract surface alveolate; alveolae commonly restricted to zones near the plate boundaries”. In contrast, Below’s illustrations (1987, Plate 17, Figures 7-15) appear to show a different species entirely, squat and with denticulate crests. His emendation of this species (Below 1987, p. 58, as Raphidodinium deflandrei) is therefore rejected here.