Back
Spiniferites ornatus
From Fensome et al., 2019:
Spiniferites ornatus
---------------------------------------------------------------------------------------------------
Original Description Duxbury, 2019:
Plate 5, Figures 1-6, 8, 9, 12
Spiniferites? sp. 1 in HEILMANN-CLAUSEN and THOMSEN 1995,
p. 307, pl. 10, figs. 1–4
Holotype: Plate 5, Figures 1–4
Paratype: Plate 5, Figures 5, 6, 8, 9
Type Locality: Heslerton No. 2 at 13.20 m (core chip), early Aptian age. Holotype: E.F. V39.0. Paratype: Q28.1
Derivation of Name: From the Latin ornatus, adorned - in reference to the surface ornament.
Diagnosis: A species with a thick, fibro-perforate endocyst and a thinner, microperforate pericyst forming short trifurcate gonal and bifurcate sutural processes. Tabulation is marked by low ridges and suturocavation is common, often best developed around the cingulum. A prominent ventral pericoel can occur, displaying a large mid-ventral claustrum. An apical horn is often present, flat-ended or bearing a terminal spike. The archeopyle is single plate precingular (3").
Dimensions: Holotype: 83 × 71 μm.
Paratype: 71 × 71 μm.
Overall: 83 (67) 56 μm × 73 (64) 48 μm.
Specimens Measured: 20.
Remarks: Spiniferites ornatus was recorded by Heilmann-Clausen and Thomsen (1995, p. 307) and referred informally to Spiniferites? sp. 1. They suggested that all specimens are pterocavate, but this does not appear to be the case, although the prominent suturocavation consistently displayed can be best developed around the cingulum.
An apical horn often occurs in this species and, in forms with a prominent cingular pericoel, it can resemble some species of Pentadinium, although the consistent occurrence of gonal and sutural processes excludes it from that genus. Spiniferites ornatus is distinctive, involving a thick, fibro-perforate endophragm, which can appear densely granular or fibroreticulate, and a thinner, microperforate periphragm; the periphragm surface often appears microreticulate. The observed age range of S. ornatus is of an early Aptian age in the Heslerton No. 2 borehole, being restricted to the 13.95 m, 13.20 m and 12.20 m samples. This age appears to be consistent with Heilmann-Clausen and Thomsen (op. cit.), who recorded it only from the early and (formal) middle Aptian of the Ahlum 1 borehole.
Spiniferites ornatus
---------------------------------------------------------------------------------------------------
Original Description Duxbury, 2019:
Plate 5, Figures 1-6, 8, 9, 12
Spiniferites? sp. 1 in HEILMANN-CLAUSEN and THOMSEN 1995,
p. 307, pl. 10, figs. 1–4
Holotype: Plate 5, Figures 1–4
Paratype: Plate 5, Figures 5, 6, 8, 9
Type Locality: Heslerton No. 2 at 13.20 m (core chip), early Aptian age. Holotype: E.F. V39.0. Paratype: Q28.1
Derivation of Name: From the Latin ornatus, adorned - in reference to the surface ornament.
Diagnosis: A species with a thick, fibro-perforate endocyst and a thinner, microperforate pericyst forming short trifurcate gonal and bifurcate sutural processes. Tabulation is marked by low ridges and suturocavation is common, often best developed around the cingulum. A prominent ventral pericoel can occur, displaying a large mid-ventral claustrum. An apical horn is often present, flat-ended or bearing a terminal spike. The archeopyle is single plate precingular (3").
Dimensions: Holotype: 83 × 71 μm.
Paratype: 71 × 71 μm.
Overall: 83 (67) 56 μm × 73 (64) 48 μm.
Specimens Measured: 20.
Remarks: Spiniferites ornatus was recorded by Heilmann-Clausen and Thomsen (1995, p. 307) and referred informally to Spiniferites? sp. 1. They suggested that all specimens are pterocavate, but this does not appear to be the case, although the prominent suturocavation consistently displayed can be best developed around the cingulum.
An apical horn often occurs in this species and, in forms with a prominent cingular pericoel, it can resemble some species of Pentadinium, although the consistent occurrence of gonal and sutural processes excludes it from that genus. Spiniferites ornatus is distinctive, involving a thick, fibro-perforate endophragm, which can appear densely granular or fibroreticulate, and a thinner, microperforate periphragm; the periphragm surface often appears microreticulate. The observed age range of S. ornatus is of an early Aptian age in the Heslerton No. 2 borehole, being restricted to the 13.95 m, 13.20 m and 12.20 m samples. This age appears to be consistent with Heilmann-Clausen and Thomsen (op. cit.), who recorded it only from the early and (formal) middle Aptian of the Ahlum 1 borehole.