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Wanaea verrucosa
From Fensome et al., 2019:
Wanaea verrucosa Riding and Helby, 2001b, p.49,51, figs.9A–L.
Holotype: Riding and Helby, 2001b, fig.9A.
Age: late Bathonian.
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Original description (Riding & Helby, 2001b):
Wanaea verrucosa sp. nov (Figs 9A-L)
1987 Wanaea sp. (granulate species); Helby et al., figs 17B, 17C
1996 Wanaea sp. A “granulate species” of Helby et al., 1987; Burger, pl. 15, figs A, B, K-M.
Previous Australian usage:
Wanea verrucosa – Helby.
Description: an intermediate to occasionally large acavate species of Wanaea which lacks a posterior paracingular flange. It has a subconical hypocyst with a prominent, wide, distally rounded antapical horn. The horn is closed distally and normally is inclined slightly toward the ventral side. The epicyst is also broadly domed, varies markedly in height and is either rounded apically or subangular. Short accessory Archeopyle sutures may be developed in the operculum only. The autophragm is robust, c. 1 µm thick and is covered by nontabular low relief ornamentation. The ornamentation is relatively varied in concentration and morphology. Scabrae, grana, verrucae, baculae and occasionally pilae are present. These elements are normally 0.5-1 µm in height, however occasionally the baculae and pilae may range up to 2.5 µm high. Individual specimens may exhibit examples of more than one ornamentation type. The ornamentation may be slightly larger in the antapical region. In some specimens the mid-lateral areas may be relatively sparsely ornamented in comparison. Coalescence of the ornamentation into short, nontabular, sinuous lineation occurs. In some specimens there may be lineation of ornamentation at the posterior paracingular parasuture. On the hypocyst there are rare instances of possible, discontinuous parasutural ornamentation or a lack or ornamentation in pandasutural zones. Ventrally, the parasulcus is marked by a narrow, shallow concavity or depression an the simple operculum is generally attached ventrally.
Dimensions (µm, n = 30): Min.(Mean)Max.
Length of entire cyst: 69 (81) 95
Length of epicyst: 11 (27) 35
length of hypocyst (incl. paracingular): 47 (62) 75
Equatorial width of hypocyst (in lateral view): 68 (83) 109
Length of antapical horn: 4 (11) 20
Width of antapical horn (at midpoint): 5 (9) 13
Comments: This distinctive species of Wanaea is characterized by the ‘domed’ epicyst and the presence of varied, dominantly nontabular, low relief ornamentation. Most specimens are scabrate, granulate and/or verrucate. However, the ornamentation is extremely variable; some specimens may be scabrate and others densely granulate/verrucate. The apical angulation which is occasionally developed is not a horn/protuberance (Fig. 9C)
Comparison: Wamaea verrucosa differs from the other species of the genus by lack of a posterior paracingular flange and the presence of consistent and normally dense, nontabular ornamanteation. The Northern Hemisphaere species Wanaea acollaris has a shorter epicyst and is partially paratabulate. Wanaea zoharensis also has nontabular ornamentation, but the elmalnts are smaller than those on W. verrucosa and they are typically coalescing. Of the similar Southern Hemisphere species, W. anoda has thin autophragm which is largely smooth and W. lacuna is cavate. Dissiliodinium caddaense (Filatoff 1975) Stover & Helby, 1987 is similar in overall morphology to W. verrucosa. The former speices has a subconical hypocyst with an antapical horn/protuberance, a ‘domed’ epicyst and scabrate/granulate autophargm, (Stober & Helby, 1987). However, D. caddaense has a compound, multiparaplate, precingular (type 1P-5P, ‘disintegration style’) Archeopyle and is normally significantly larger than W. verrucosa. If the Archeopyle of D. caddaense has not started to open, the specimen may be identified as W. verucosa (see Stover & Helby, 1987, fig 4).
Derivation of name: From the Latin, verruca, meaning wart and referring to the characteristic verrrucate ornamentation of this species.
Holotype and type locality: Fig. 9A, CPC 35875, ditch cuttings at 800.00m in Stag-1 well.
Stratigraphical distribution. Wanaea verrucosa is confined to the Bathonian Wanaea verrucosa Zone (subzones 7ciaiii-7ciai) (Figs 11, 12; Foster, this volume; Helby & Partridge, in prep.)
Wanaea verrucosa Riding and Helby, 2001b, p.49,51, figs.9A–L.
Holotype: Riding and Helby, 2001b, fig.9A.
Age: late Bathonian.
---------------------------------------------------------------------------------------------------
Original description (Riding & Helby, 2001b):
Wanaea verrucosa sp. nov (Figs 9A-L)
1987 Wanaea sp. (granulate species); Helby et al., figs 17B, 17C
1996 Wanaea sp. A “granulate species” of Helby et al., 1987; Burger, pl. 15, figs A, B, K-M.
Previous Australian usage:
Wanea verrucosa – Helby.
Description: an intermediate to occasionally large acavate species of Wanaea which lacks a posterior paracingular flange. It has a subconical hypocyst with a prominent, wide, distally rounded antapical horn. The horn is closed distally and normally is inclined slightly toward the ventral side. The epicyst is also broadly domed, varies markedly in height and is either rounded apically or subangular. Short accessory Archeopyle sutures may be developed in the operculum only. The autophragm is robust, c. 1 µm thick and is covered by nontabular low relief ornamentation. The ornamentation is relatively varied in concentration and morphology. Scabrae, grana, verrucae, baculae and occasionally pilae are present. These elements are normally 0.5-1 µm in height, however occasionally the baculae and pilae may range up to 2.5 µm high. Individual specimens may exhibit examples of more than one ornamentation type. The ornamentation may be slightly larger in the antapical region. In some specimens the mid-lateral areas may be relatively sparsely ornamented in comparison. Coalescence of the ornamentation into short, nontabular, sinuous lineation occurs. In some specimens there may be lineation of ornamentation at the posterior paracingular parasuture. On the hypocyst there are rare instances of possible, discontinuous parasutural ornamentation or a lack or ornamentation in pandasutural zones. Ventrally, the parasulcus is marked by a narrow, shallow concavity or depression an the simple operculum is generally attached ventrally.
Dimensions (µm, n = 30): Min.(Mean)Max.
Length of entire cyst: 69 (81) 95
Length of epicyst: 11 (27) 35
length of hypocyst (incl. paracingular): 47 (62) 75
Equatorial width of hypocyst (in lateral view): 68 (83) 109
Length of antapical horn: 4 (11) 20
Width of antapical horn (at midpoint): 5 (9) 13
Comments: This distinctive species of Wanaea is characterized by the ‘domed’ epicyst and the presence of varied, dominantly nontabular, low relief ornamentation. Most specimens are scabrate, granulate and/or verrucate. However, the ornamentation is extremely variable; some specimens may be scabrate and others densely granulate/verrucate. The apical angulation which is occasionally developed is not a horn/protuberance (Fig. 9C)
Comparison: Wamaea verrucosa differs from the other species of the genus by lack of a posterior paracingular flange and the presence of consistent and normally dense, nontabular ornamanteation. The Northern Hemisphaere species Wanaea acollaris has a shorter epicyst and is partially paratabulate. Wanaea zoharensis also has nontabular ornamentation, but the elmalnts are smaller than those on W. verrucosa and they are typically coalescing. Of the similar Southern Hemisphere species, W. anoda has thin autophragm which is largely smooth and W. lacuna is cavate. Dissiliodinium caddaense (Filatoff 1975) Stover & Helby, 1987 is similar in overall morphology to W. verrucosa. The former speices has a subconical hypocyst with an antapical horn/protuberance, a ‘domed’ epicyst and scabrate/granulate autophargm, (Stober & Helby, 1987). However, D. caddaense has a compound, multiparaplate, precingular (type 1P-5P, ‘disintegration style’) Archeopyle and is normally significantly larger than W. verrucosa. If the Archeopyle of D. caddaense has not started to open, the specimen may be identified as W. verucosa (see Stover & Helby, 1987, fig 4).
Derivation of name: From the Latin, verruca, meaning wart and referring to the characteristic verrrucate ornamentation of this species.
Holotype and type locality: Fig. 9A, CPC 35875, ditch cuttings at 800.00m in Stag-1 well.
Stratigraphical distribution. Wanaea verrucosa is confined to the Bathonian Wanaea verrucosa Zone (subzones 7ciaiii-7ciai) (Figs 11, 12; Foster, this volume; Helby & Partridge, in prep.)