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Batiacasphaera vestigium
From Fensome et al., 2019:
Batiacasphaera vestigium Dolby, 2019, VRp.2,4, pl.1, figs.1–6. Holotype: Dolby, 2019, pl.1, fig.1. Questionable assignment: Dolby (2019, VRp.2,4). Age: Aptian - early Albian.
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Original description: [Dolby, 2019] (as Batioladinium? vestigium var. vestigium): !!
Batioladinium? vestigium var. vestigium sp. et var. nov.
Plate 1, figures 1–4
Synonymy. Dinocyst OS3, Dolby et al. 2013, pl. 1, fig. 8.
Holotype. Plate 1, figure 1.
Type locality. Devon Leismer 1AA/08-14-76-7W4, Alberta, 361.6m, Wabiskaw D Member of the Clearwater Formation.
Repository. National Collection of Type Invertebrate and Plant Fossils, Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E8, under curation number GSC 139216.
Diagnosis. A species of Batioladinium? that lacks the deep, anterior ventral notch typical of the genus and in which the antapical horns are only weakly discernible.
Description. Shape: The autophragm is ellipsoidal. An apical horn varies from a small boss 3.5mm in diameter to a narrow horn 7mm long and 3mm wide with a solid tip. The antapical horns are vestigial to very small. They are expressed as slight thickenings of the autophragm on either side of a weak antapical invagination or as 1–4 mm long, equal or unequal rounded lobes that appear as folds in laterally compressed specimens. Tabulation: Indicated only by archaeopyle sutures. Archaeopyle: Apical; operculum usually absent, formed from 4–5 climactal paraplates and the horn. Cingulum: rarely visible; when discernible by a slight thinning of the autophragm or by narrow folds. Wall: Autophragm smooth to scabrate. Many specimens have a partial to complete kalyptra, 2–4 μm wide.
Dimensions [min (mode) max].
Length: 39 (48) 54 μm (20 specimens). Holotype: 59 μm.
Breadth: 27 (30) 35 μm. Holotype: 33 μm.
Derivation of name. Named for the vestigial antapical horns.
Discussion. This species is distinguished by the lack of a deep, anterior ventral notch and by the vestigial antapical horns. Small, very thin laminae within the kalyptra suggest that these are possibly decayed wall layers.
Comparison. Batioladinium micropodum has a thick, complex, ‘spongy’ periphragm. Batioladinium exiguum has larger apical and antapical projections. Both have deep anterior ventral notches.
Occurrence. Aptian to early Albian, middle and upper McMurray Formation, Clearwater Formation and lower Grand Rapids Formation.
Batiacasphaera vestigium Dolby, 2019, VRp.2,4, pl.1, figs.1–6. Holotype: Dolby, 2019, pl.1, fig.1. Questionable assignment: Dolby (2019, VRp.2,4). Age: Aptian - early Albian.
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Original description: [Dolby, 2019] (as Batioladinium? vestigium var. vestigium): !!
Batioladinium? vestigium var. vestigium sp. et var. nov.
Plate 1, figures 1–4
Synonymy. Dinocyst OS3, Dolby et al. 2013, pl. 1, fig. 8.
Holotype. Plate 1, figure 1.
Type locality. Devon Leismer 1AA/08-14-76-7W4, Alberta, 361.6m, Wabiskaw D Member of the Clearwater Formation.
Repository. National Collection of Type Invertebrate and Plant Fossils, Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E8, under curation number GSC 139216.
Diagnosis. A species of Batioladinium? that lacks the deep, anterior ventral notch typical of the genus and in which the antapical horns are only weakly discernible.
Description. Shape: The autophragm is ellipsoidal. An apical horn varies from a small boss 3.5mm in diameter to a narrow horn 7mm long and 3mm wide with a solid tip. The antapical horns are vestigial to very small. They are expressed as slight thickenings of the autophragm on either side of a weak antapical invagination or as 1–4 mm long, equal or unequal rounded lobes that appear as folds in laterally compressed specimens. Tabulation: Indicated only by archaeopyle sutures. Archaeopyle: Apical; operculum usually absent, formed from 4–5 climactal paraplates and the horn. Cingulum: rarely visible; when discernible by a slight thinning of the autophragm or by narrow folds. Wall: Autophragm smooth to scabrate. Many specimens have a partial to complete kalyptra, 2–4 μm wide.
Dimensions [min (mode) max].
Length: 39 (48) 54 μm (20 specimens). Holotype: 59 μm.
Breadth: 27 (30) 35 μm. Holotype: 33 μm.
Derivation of name. Named for the vestigial antapical horns.
Discussion. This species is distinguished by the lack of a deep, anterior ventral notch and by the vestigial antapical horns. Small, very thin laminae within the kalyptra suggest that these are possibly decayed wall layers.
Comparison. Batioladinium micropodum has a thick, complex, ‘spongy’ periphragm. Batioladinium exiguum has larger apical and antapical projections. Both have deep anterior ventral notches.
Occurrence. Aptian to early Albian, middle and upper McMurray Formation, Clearwater Formation and lower Grand Rapids Formation.