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Canningia grahamii
Etymology. The species is named in honor of Raymond Graham (b. 1951) of Courtenay, British Columbia, for his many contributions to the paleontology of the eastern North Pacific.
Holotype. Plate 3A–D, Sample 8 (GSC C-711376), slide E6-19 E, EF E40/0.
Paratypes. Plate 3E–H, Sample 8, slide E6-19 E, EF H37/3; Plate 3I, Sample 8, slide E6-19 E, EF M46/1; Plate 4A–C, Sample 8, slide E6-19 E, EF V26/1; Plate 4D–F, Sample 8, slide E6-19 E, EF G46/2; Plate 4G–I, Sample 8, slide E6-19 E, EF T28/0; Plate 5A–D, Sample 8, stub 24D07, specimen 8 (CEDiT2024P186); Plate 5E, F, Sample 8, stub 24D08, specimen 12 (CEDiT2024P187); Plate 5G, Sample 8, stub 24D08, specimen 8 (CEDiT2024P188); Plate 6A–E, Sample 8, stub 24D08, specimen 13 (CEDiT2024P189); Plate 6F, Sample 8, stub 24D08, specimen 16 (CEDiT2024P190).
Type locality. Northwest Bay Quarry (49.2986◦-124.2153◦), ~500 m northwest of the log sort entrance, eastern Vancouver Island, British Columbia, Canada (Fig. 1B, locality 4).
Type stratum. Lower upper Trent River Formation, lower Campanian.
Repository. Geological Survey of Canada.
Diagnosis. A species of Canningia that is proximochorate, with subspherical to subpentagonal autophragm ambitus. Wall layers closely appressed in mid-dorsal and mid-ventral areas. Autophragm and ectophragm resolved as an intergradational lattice of interlaced costate cord-like elements expanding in alignment to form clearly demarcated cingular ridges and tufts in lateral and antapical regions.
Description. Cyst proximochorate with subspherical to subpentagonal ambitus, wider than long discounting operculum. Ectocyst and autocyst length-to-width ratios essentially the same at 0.84. Irregularly holocavate with wall layers forming a spongey complex of luxuriae chacterized by a mesh-like network of microcostate columns of intergradational autophragm and ectophragm (Plate 5D; Plate 6C, E). The ambitus is disjunct such that plumes of interlaced ectophragm along the margins extending toward the antapical region lend to a ragged or shaggy appearance (Plate 3C, D, G, I). The ectophragm lattice is most closely appressed to the autophragm in the pre- and postcingular areas as well as across the deep ventral sulcal region where it forms a dense, fibroreticulate to rugoreticulate corium (Plate 6B, C, E). Cingulum laevorotatory, demarcated by ectophragmal ridges; offset by two cingulum widths. Archaeopyle apical, with formula A(1–4′); operculum detached. Tabulation is indicated by the archeopyle margin and by the alignment of raised columns of ectophragm forming sutural ridges demarcating the 2′′–3′′, 3′′–4′′, 2′′′–3′′′, and 3′′′–4′′′ plate boundaries (e.g., Plate 5C; Plate 6B). Inferred reflected tabulation formula 4′, 6′′, Xc, 5′′′, 1p, 1′′′′. Autocyst antapex generally rounded, occasionally asymmetrical.
Dimensions. Holotype: ectocyst length (without operculum) =42.9 μm; ectocyst width (without operculum) =61.0 μm; ectocyst length-to- width ratio =0.7; autocyst length (without operculum) =51.4 μm; autocyst width (without operculum) =52.0 μm. Range: ectocyst length (without operculum) =42.9 (50.8) 59.0 μm; ectocyst width =49.5 (61.7) 72.2 μm; ectocyst length-to-width ratio =0.7 (0.8) 1.0; autocyst length (without operculum) =37.0 (44.9) 52.3 μm; autocyst width =43.7 (53.9) 65.7 μm; autocyst length-to-width ratio =0.7 (0.8) 1.0. Specimens measured: 30. Values presented in Appendix B, Table B.2.
Comparison. Canningia grahamii sp. nov. differs from other members of the genus in being characterized by an intricate network of cord-like elements effectively resolved as an intergradational lattice of autophragm and ectophragm. Most species of Canningia also express greater uniformity of holocavation with a measure of ectophragm separation (ectocoel) presenting consistently across the ambital periphery. When ical and equatorial ‘horn’ projection as seen in the species Canningia diastatikos (McLachlan et al., 2019, pl. 3, figs. 7–9) and Canningia glomerata (Clarke and Verdier, 1967, pl. 14, fig. 2; Fensome et al., 2019b, fig. 12O). Likewise, the ectophragm of some taxa may expand outward to form antapical “lobes” as described in Canningia fairfieldensis and figured by Willumsen(2012, p. 59; pl. 2, fig. 3). In other instances, the ectophragm may expand to manifest more marginally irregular plumes, as is the case with the “horns” of variants of Canningia wilsonii (Slimani et al., 2021, p. 6; pl. 1, figs. I, L), which share surficial irregularity with Ca. grahamii sp. nov.
The superficially similar Cyclonephelium deconinckii, described by Boltenhagen(1977) from the Campanian strata of Gabon, is distinguished by peripheral rows of short, interconnected appendages, and by longer appendages clustered in tufts, projecting from antapical protuberances. Both species share their most pronounced appendage development in the lateral and antapical regions. However, the tufts exhibited by specimens of Ca. grahamii sp. nov. are effectively plumes or projections of an ectophragm lattice that is otherwise more closely appressed in the pre- and postcingular dorsal regions, whereas the tufts of Cy. deconinckii appear to consist of more ribbon-like appendage clusters, akin to joined processes in the examples figured by Boltenhagen (1977, pl. 4, figs. 5a, 5b, 6). Furthermore, Boltenhagen (1977) makes no mention of a defined cingulum or microreticulate wall which would otherwise be suggestive of a possibly reduced ectophragm warranting placement of the taxon within Canningia. In addition to a clearly expressed cingulum, all observed specimens of Ca. grahamii sp. nov. bear ridges of raised ectophragm demarcating precingular 2′′–3′′ and 3′′–4′′ as well as postcingular 2′′′–3′′′ and 3′′′–4′′′ plate boundaries. The material attributed to Cy. deconinckii by Boltenhagen(1977) has no such sutural definition, and the species also differs in lacking cingular ridges with transdorsal continuity. If at all visible, the cingular plate series of Cy. deconinckii may appear only as faint indications along the lateral margins (Boltenhagen, 1977, pl. 4, fig. 5a). The nature of the tufts in Cy. deconinckii as potential process clusters combined with indiscernible dorsal tabulation sees greater affinity of the species with Cyclonephelium, although the form may be an end member of the same areoligeracean plexus. We agree with Fensome et al.(2019b) that the Cy. deconinckii type material of Boltenhagen(1977) requires further examination to resolve its morphology.
Stratigraphic range. Upper Santonian–lower Campanian.
Occurrence. Canningia grahamii sp. nov. has been recovered from exposures of the lower upper Trent River Formation in the Northwest Bay Quarry, eastern Vancouver Island (Sample 8) and from an outcrop of the lower section of the Trent River Formation (Sample 2) exposed on the Trent River within the Comox OA, British Columbia, Canada. Until the material of Boltenhagen(1977) is re-examined, it remains a possibility that the species could also occur within the Campanian strata of Gabon.
Holotype. Plate 3A–D, Sample 8 (GSC C-711376), slide E6-19 E, EF E40/0.
Paratypes. Plate 3E–H, Sample 8, slide E6-19 E, EF H37/3; Plate 3I, Sample 8, slide E6-19 E, EF M46/1; Plate 4A–C, Sample 8, slide E6-19 E, EF V26/1; Plate 4D–F, Sample 8, slide E6-19 E, EF G46/2; Plate 4G–I, Sample 8, slide E6-19 E, EF T28/0; Plate 5A–D, Sample 8, stub 24D07, specimen 8 (CEDiT2024P186); Plate 5E, F, Sample 8, stub 24D08, specimen 12 (CEDiT2024P187); Plate 5G, Sample 8, stub 24D08, specimen 8 (CEDiT2024P188); Plate 6A–E, Sample 8, stub 24D08, specimen 13 (CEDiT2024P189); Plate 6F, Sample 8, stub 24D08, specimen 16 (CEDiT2024P190).
Type locality. Northwest Bay Quarry (49.2986◦-124.2153◦), ~500 m northwest of the log sort entrance, eastern Vancouver Island, British Columbia, Canada (Fig. 1B, locality 4).
Type stratum. Lower upper Trent River Formation, lower Campanian.
Repository. Geological Survey of Canada.
Diagnosis. A species of Canningia that is proximochorate, with subspherical to subpentagonal autophragm ambitus. Wall layers closely appressed in mid-dorsal and mid-ventral areas. Autophragm and ectophragm resolved as an intergradational lattice of interlaced costate cord-like elements expanding in alignment to form clearly demarcated cingular ridges and tufts in lateral and antapical regions.
Description. Cyst proximochorate with subspherical to subpentagonal ambitus, wider than long discounting operculum. Ectocyst and autocyst length-to-width ratios essentially the same at 0.84. Irregularly holocavate with wall layers forming a spongey complex of luxuriae chacterized by a mesh-like network of microcostate columns of intergradational autophragm and ectophragm (Plate 5D; Plate 6C, E). The ambitus is disjunct such that plumes of interlaced ectophragm along the margins extending toward the antapical region lend to a ragged or shaggy appearance (Plate 3C, D, G, I). The ectophragm lattice is most closely appressed to the autophragm in the pre- and postcingular areas as well as across the deep ventral sulcal region where it forms a dense, fibroreticulate to rugoreticulate corium (Plate 6B, C, E). Cingulum laevorotatory, demarcated by ectophragmal ridges; offset by two cingulum widths. Archaeopyle apical, with formula A(1–4′); operculum detached. Tabulation is indicated by the archeopyle margin and by the alignment of raised columns of ectophragm forming sutural ridges demarcating the 2′′–3′′, 3′′–4′′, 2′′′–3′′′, and 3′′′–4′′′ plate boundaries (e.g., Plate 5C; Plate 6B). Inferred reflected tabulation formula 4′, 6′′, Xc, 5′′′, 1p, 1′′′′. Autocyst antapex generally rounded, occasionally asymmetrical.
Dimensions. Holotype: ectocyst length (without operculum) =42.9 μm; ectocyst width (without operculum) =61.0 μm; ectocyst length-to- width ratio =0.7; autocyst length (without operculum) =51.4 μm; autocyst width (without operculum) =52.0 μm. Range: ectocyst length (without operculum) =42.9 (50.8) 59.0 μm; ectocyst width =49.5 (61.7) 72.2 μm; ectocyst length-to-width ratio =0.7 (0.8) 1.0; autocyst length (without operculum) =37.0 (44.9) 52.3 μm; autocyst width =43.7 (53.9) 65.7 μm; autocyst length-to-width ratio =0.7 (0.8) 1.0. Specimens measured: 30. Values presented in Appendix B, Table B.2.
Comparison. Canningia grahamii sp. nov. differs from other members of the genus in being characterized by an intricate network of cord-like elements effectively resolved as an intergradational lattice of autophragm and ectophragm. Most species of Canningia also express greater uniformity of holocavation with a measure of ectophragm separation (ectocoel) presenting consistently across the ambital periphery. When ical and equatorial ‘horn’ projection as seen in the species Canningia diastatikos (McLachlan et al., 2019, pl. 3, figs. 7–9) and Canningia glomerata (Clarke and Verdier, 1967, pl. 14, fig. 2; Fensome et al., 2019b, fig. 12O). Likewise, the ectophragm of some taxa may expand outward to form antapical “lobes” as described in Canningia fairfieldensis and figured by Willumsen(2012, p. 59; pl. 2, fig. 3). In other instances, the ectophragm may expand to manifest more marginally irregular plumes, as is the case with the “horns” of variants of Canningia wilsonii (Slimani et al., 2021, p. 6; pl. 1, figs. I, L), which share surficial irregularity with Ca. grahamii sp. nov.
The superficially similar Cyclonephelium deconinckii, described by Boltenhagen(1977) from the Campanian strata of Gabon, is distinguished by peripheral rows of short, interconnected appendages, and by longer appendages clustered in tufts, projecting from antapical protuberances. Both species share their most pronounced appendage development in the lateral and antapical regions. However, the tufts exhibited by specimens of Ca. grahamii sp. nov. are effectively plumes or projections of an ectophragm lattice that is otherwise more closely appressed in the pre- and postcingular dorsal regions, whereas the tufts of Cy. deconinckii appear to consist of more ribbon-like appendage clusters, akin to joined processes in the examples figured by Boltenhagen (1977, pl. 4, figs. 5a, 5b, 6). Furthermore, Boltenhagen (1977) makes no mention of a defined cingulum or microreticulate wall which would otherwise be suggestive of a possibly reduced ectophragm warranting placement of the taxon within Canningia. In addition to a clearly expressed cingulum, all observed specimens of Ca. grahamii sp. nov. bear ridges of raised ectophragm demarcating precingular 2′′–3′′ and 3′′–4′′ as well as postcingular 2′′′–3′′′ and 3′′′–4′′′ plate boundaries. The material attributed to Cy. deconinckii by Boltenhagen(1977) has no such sutural definition, and the species also differs in lacking cingular ridges with transdorsal continuity. If at all visible, the cingular plate series of Cy. deconinckii may appear only as faint indications along the lateral margins (Boltenhagen, 1977, pl. 4, fig. 5a). The nature of the tufts in Cy. deconinckii as potential process clusters combined with indiscernible dorsal tabulation sees greater affinity of the species with Cyclonephelium, although the form may be an end member of the same areoligeracean plexus. We agree with Fensome et al.(2019b) that the Cy. deconinckii type material of Boltenhagen(1977) requires further examination to resolve its morphology.
Stratigraphic range. Upper Santonian–lower Campanian.
Occurrence. Canningia grahamii sp. nov. has been recovered from exposures of the lower upper Trent River Formation in the Northwest Bay Quarry, eastern Vancouver Island (Sample 8) and from an outcrop of the lower section of the Trent River Formation (Sample 2) exposed on the Trent River within the Comox OA, British Columbia, Canada. Until the material of Boltenhagen(1977) is re-examined, it remains a possibility that the species could also occur within the Campanian strata of Gabon.