Back
Fromea plicata
From Fensome et al., 2019:
Fromea plicata Dolby, 2019, VRp.5–6, pl.1, figs.18–20. Holotype: Dolby, 2019, pl.1, fig.18. Age: Aptian - early Albian.
---------------------------------------------------------------------------------------------------
Original description (Dolby, 2019):
Fromea? plicata sp. nov.
Plate 1, figures 18–20
Synonymy. ?Fromea sp. OS1, Dolby et al. 2013, pl. 1, fig. 7.
Holotype. Plate 1, figure 18.
Type locality. Sunshine Liege 1AA/06-25-91-18W4, Alberta, 232.2m, upper McMurray 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 139233.
Diagnosis. A possible species of Fromea with a slightly ‘dorsally’ offset, polar pylome and a distinct pattern of ‘ventral’ folds that resemble a humanoid stick figure.
Description. Shape: Sub-cylindrical, tapering slightly towards the antapex.
Pylome: Circular, apical but always ‘dorsally’ offset to varying degrees, occasionally with slightly thickened margin. The operculum is free.
Wall: Smooth to faintly scabrate with a slight equatorial thinning of the test at mid-length and a distinct pattern of ‘ventral’ folds. One longitudinal fold starts at the apex and runs 2/3 to 3/4 of the length of the cyst. Two start at the antapical corners and angle inwards to meet the termination of the first fold. Two more start at the apical corners and join the first fold near its mid-point. The overall fold pattern resembles a humanoid stick figure.
Dimensions [min (mode) max].
Length: 39 (48) 53 μm (20 specimens). Holotype: 49 μm.
Breadth: 36 (41) 47 μm. Holotype: 43 μm.
Pylome: 12 (15) 18 μm. Holotype: 17 μm.
Derivation of name. Named for the distinctive pattern of folds.
Comparison. Nummus has a ‘dorsally’ offset pylome but marked ‘ventral’ thinning. Fromea quadrugata is flask shaped, and has an apical pylome and four folds arranged in a square with one corner pointing to the apex.
Occurrence. Aptian to early Albian, middle and upper McMurray Formation, Clearwater Formation and lower Grand Rapids Formation.
Fromea plicata Dolby, 2019, VRp.5–6, pl.1, figs.18–20. Holotype: Dolby, 2019, pl.1, fig.18. Age: Aptian - early Albian.
---------------------------------------------------------------------------------------------------
Original description (Dolby, 2019):
Fromea? plicata sp. nov.
Plate 1, figures 18–20
Synonymy. ?Fromea sp. OS1, Dolby et al. 2013, pl. 1, fig. 7.
Holotype. Plate 1, figure 18.
Type locality. Sunshine Liege 1AA/06-25-91-18W4, Alberta, 232.2m, upper McMurray 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 139233.
Diagnosis. A possible species of Fromea with a slightly ‘dorsally’ offset, polar pylome and a distinct pattern of ‘ventral’ folds that resemble a humanoid stick figure.
Description. Shape: Sub-cylindrical, tapering slightly towards the antapex.
Pylome: Circular, apical but always ‘dorsally’ offset to varying degrees, occasionally with slightly thickened margin. The operculum is free.
Wall: Smooth to faintly scabrate with a slight equatorial thinning of the test at mid-length and a distinct pattern of ‘ventral’ folds. One longitudinal fold starts at the apex and runs 2/3 to 3/4 of the length of the cyst. Two start at the antapical corners and angle inwards to meet the termination of the first fold. Two more start at the apical corners and join the first fold near its mid-point. The overall fold pattern resembles a humanoid stick figure.
Dimensions [min (mode) max].
Length: 39 (48) 53 μm (20 specimens). Holotype: 49 μm.
Breadth: 36 (41) 47 μm. Holotype: 43 μm.
Pylome: 12 (15) 18 μm. Holotype: 17 μm.
Derivation of name. Named for the distinctive pattern of folds.
Comparison. Nummus has a ‘dorsally’ offset pylome but marked ‘ventral’ thinning. Fromea quadrugata is flask shaped, and has an apical pylome and four folds arranged in a square with one corner pointing to the apex.
Occurrence. Aptian to early Albian, middle and upper McMurray Formation, Clearwater Formation and lower Grand Rapids Formation.