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Gochteodinia minuta
Plate 2, Figures 15–20; Plate 35, Figure 8
Holotype: Plate 2, Figure 17, 18.
Paratype: Plate 2, Figure 15, 16.
Type Locality: Speeton Clay Formation, early Hauterivian.
Holotype: Slide D2A(4), amblygonium ammonite Zone. E.F.
N41.1. Paratype: Slide D1(1), amblygonium/noricum ammonite Zone. E.F. S34.3.
Derivation of Name: From the Latin minutus, little, small – in reference to the small size of this species.
Diagnosis: Asmall, spheroidal to ellipsoidal species with a low, broad and distally-rounded apical prominence, bearing a dense, finely-granular ornament over the entire surface. Numerous, evenly-spaced, relatively long spines cover the main body, but these are absent from the apical horn. Spines are broad-based and taper to acuminate or capitate tips. Tabulation is expressed only by the archeopyle margin, which involves the displacement of two intercalary plates.
Dimensions: Holotype: Body length - 41 μm.Width - 43 μm.
Paratype: Length - 46 μm. Width - 43 μm.
Overall: 46 (41) 38 μm × 43 (40) 35 μm
Specimens Measured: 4.
Remarks: Gochteodinia minuta Duxbury n. sp. is a very small and relatively broad species for the genus. In the present study it was restricted to Speeton Beds D2C to D1 (early Hauterivian, amblygonium to noricum ammonite Zones), where it occurred together with Protoellipsodinium vacuolatum Duxbury 2018 and very common Protoellipsodinium seghire subsp. medaaure Below 1981, spinose taxa of a similar size and outline. Because of their similarities these forms are sometimes difficult to discriminate using low magnification.
A specimen of informal species Gochteodinia sp. D3E from the early Valanginian of Speeton was illustrated by Duxbury (2019, Plate 20, Fig. 8), and this is another small, relatively rounded taxon displaying several features similar to those observed in G. minuta. These include a low, bluntly-rounded apical termination and, because of the much reduced horn, a “high” position of the large two-plate intercalary archeopyle. Gochteodinia sp. D3E differs, however, in having much shorter spines.
Holotype: Plate 2, Figure 17, 18.
Paratype: Plate 2, Figure 15, 16.
Type Locality: Speeton Clay Formation, early Hauterivian.
Holotype: Slide D2A(4), amblygonium ammonite Zone. E.F.
N41.1. Paratype: Slide D1(1), amblygonium/noricum ammonite Zone. E.F. S34.3.
Derivation of Name: From the Latin minutus, little, small – in reference to the small size of this species.
Diagnosis: Asmall, spheroidal to ellipsoidal species with a low, broad and distally-rounded apical prominence, bearing a dense, finely-granular ornament over the entire surface. Numerous, evenly-spaced, relatively long spines cover the main body, but these are absent from the apical horn. Spines are broad-based and taper to acuminate or capitate tips. Tabulation is expressed only by the archeopyle margin, which involves the displacement of two intercalary plates.
Dimensions: Holotype: Body length - 41 μm.Width - 43 μm.
Paratype: Length - 46 μm. Width - 43 μm.
Overall: 46 (41) 38 μm × 43 (40) 35 μm
Specimens Measured: 4.
Remarks: Gochteodinia minuta Duxbury n. sp. is a very small and relatively broad species for the genus. In the present study it was restricted to Speeton Beds D2C to D1 (early Hauterivian, amblygonium to noricum ammonite Zones), where it occurred together with Protoellipsodinium vacuolatum Duxbury 2018 and very common Protoellipsodinium seghire subsp. medaaure Below 1981, spinose taxa of a similar size and outline. Because of their similarities these forms are sometimes difficult to discriminate using low magnification.
A specimen of informal species Gochteodinia sp. D3E from the early Valanginian of Speeton was illustrated by Duxbury (2019, Plate 20, Fig. 8), and this is another small, relatively rounded taxon displaying several features similar to those observed in G. minuta. These include a low, bluntly-rounded apical termination and, because of the much reduced horn, a “high” position of the large two-plate intercalary archeopyle. Gochteodinia sp. D3E differs, however, in having much shorter spines.