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Spiniferites modestus
Plate 25, Figures 3, 4, 8, 11
Holotype: Plate 25, Figures 3, 4.
Type Locality: Speeton Clay Formation, Bed D2C, early Hauterivian, amblygonium ammonite Zone. Holotype: Slide D2C(1), E.F. M53.0
Derivation of Name: From the Latin modestus, moderate, unassuming- in reference to the small, delicate nature of this species.
Diagnosis: A small species with a thin-walled, ovoidal endocyst, covered by a dense, finely granular ornament, and a closely attached, smooth, delicate pericyst. The periphragm forms sutural crests of varying height, which can be particularly well developed on the dorsal hypocyst and which bear short gonal and sutural processes. Processes can be distally furcate but are usually capitate so that sutural crests effectively bear rows of slender spines. A parallel-sided cingulum is clearly seen and a ventral pericoel is invariably present, associated with a sulcal claustrum. The archeopyle is single plate precingular (3").
Dimensions: Holotype: 56 × 51 μm
All measured specimens: Overall 58 (51) 48 μm × 53 (48) 43 μm.
Specimens Measured: 14.
Remarks: Spiniferites modestus n. sp. differs from other species of the genus in its combination of small size, densely but finely granular endocyst, smooth pericyst and processes which tend to be reduced to slender, capitate spines. It is similar in some respects to informal species Spiniferites sp. B (below) but is relatively small and delicate, with a significantly thinner endophragm. Also, the epicyst of S. modestus is rounded triangular in plan view, in contrast to the hemispherical endocyst of Spiniferites sp. B.This species was present throughout much of the early Hauterivian, being recorded between Speeton Beds D2D and C7E (amblygonium to inversum ammonite Zones), and it was common between Beds C9B and C8B (regale Zone).
Holotype: Plate 25, Figures 3, 4.
Type Locality: Speeton Clay Formation, Bed D2C, early Hauterivian, amblygonium ammonite Zone. Holotype: Slide D2C(1), E.F. M53.0
Derivation of Name: From the Latin modestus, moderate, unassuming- in reference to the small, delicate nature of this species.
Diagnosis: A small species with a thin-walled, ovoidal endocyst, covered by a dense, finely granular ornament, and a closely attached, smooth, delicate pericyst. The periphragm forms sutural crests of varying height, which can be particularly well developed on the dorsal hypocyst and which bear short gonal and sutural processes. Processes can be distally furcate but are usually capitate so that sutural crests effectively bear rows of slender spines. A parallel-sided cingulum is clearly seen and a ventral pericoel is invariably present, associated with a sulcal claustrum. The archeopyle is single plate precingular (3").
Dimensions: Holotype: 56 × 51 μm
All measured specimens: Overall 58 (51) 48 μm × 53 (48) 43 μm.
Specimens Measured: 14.
Remarks: Spiniferites modestus n. sp. differs from other species of the genus in its combination of small size, densely but finely granular endocyst, smooth pericyst and processes which tend to be reduced to slender, capitate spines. It is similar in some respects to informal species Spiniferites sp. B (below) but is relatively small and delicate, with a significantly thinner endophragm. Also, the epicyst of S. modestus is rounded triangular in plan view, in contrast to the hemispherical endocyst of Spiniferites sp. B.This species was present throughout much of the early Hauterivian, being recorded between Speeton Beds D2D and C7E (amblygonium to inversum ammonite Zones), and it was common between Beds C9B and C8B (regale Zone).