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Graptodinium inconditum
Graptodinium inconditum Clowes, 2013, p.318,321, pl.1, figs.1–6, pl.2, figs.1–12.
Holotype: Clowes, 2013, pl.1, figs.1–3.
Age: Lutetian–Chattian.
Original description: Clowes, 2013
Graptodinium inconditum sp. nov. Plate 1, figures 1–6; Plate 2, figures 1–12
Synonyms:
Microdinium sp. 1; Châteauneuf 1980, p. 143, pl. 26, figs. 5–7.
Corrudinium sp.; Wilson 1982a, pl. 1, fig. 6.
Histiocysta sp.; Goodman & Ford 1983, pl. 9, figs. 7–8.
Histiocysta sp.; Clowes & Morgans 1984, p. 32, pl. 2, fig. 3.
Microdinium sp. 1 of Châteauneuf; Edwards 1984, pl. 2, fig. 6.
Histiocysta sp.; Wilson 1985, p. 99, pl. 1, fig. 8.
Microdinium reticulatum Vozzhennikova 1967; De Coninck 1986, p. 16, pl. 6, figs. 1–7, pl. 7, figs.14–16.
Histiocysta spp. of Goodman and Ford, 1983; Head & Norris 1989, p. 530, pl. 3, figs. 5–9.
Histiocysta sp.; Brinkhuis 1992, pl. 17, figs. 12–14.
Histiocysta sp.; Stover & Hardenbol 1994, p. 32, pl. 2, figs. 13–14.
Microdinium sp. 1 of Châteauneuf (1980); Schiøler 2005, pl. 17, figs. 14–15.
Holotype. Specimen L16341/SM4946, Plate 1, figs. 1–3; sample I43/f093, Burnside Formation, Puketeraki core 45.90–45.85 m (Wilson & McMillan 1996, p. 15, 54–58; note that core measurements cited therein commence from the base of the core), Dunedin, New Zealand, grid ref. I43/2655 0313; Upper Bortonian– Kaiatan Stage (Bartonian–Priabonian). Overall length = 40 µm (excludes displaced operculum), breadth = 40 µm at widest point (posterior suture of cingulum), height of sutural septa = 4.5 µm at antapex.
Paratypes. Specimen L16341/SM4945 (Plate 1, figures 4–6); specimen L16341/SM4943 (Plate 2, figures 1–6); specimen L16341/SM4947 (Plate 2, figures 7, 8); specimen L16341/SM4944 (Plate 2, figure 9). All paratypes from sample I43/f093, Burnside Formation, Puketeraki core 45.90–45.85 m, Dunedin, New Zealand, grid ref. I43/2655 0313; Upper Bortonian–Kaiatan Stage (Bartonian–Priabonian).
Derivation of name. From the Latin inconditus, meaning irregular, with reference to the intratabular ornamentation.
Description. Cysts small, proximate, subspherical to slightly prolate, lacking horns; the epicyst somewhat or, more usually, considerably smaller than the hypocyst. Cyst walls apparently single-layered. Archaeopyle apical, type (tA); operculum free or, more commonly, attached. Processes lacking; ornament comprising low, solid sutural and intratabular septa. Sutural septa approximately 2.5 to 4.5 mm high, particularly distinct in equatorial view, forming a well-defined cladopyxiacean tabulation, ?4’, ?0a, 6’’, 6c, 6’’’, 1p, 1’’’’. Accessory septa comprising the irregular intratabular ornament forming an incomplete reticulum, sometimes continuous with the sutural septa, sometimes separated by a narrow clear area (Plate 1, figures 1, 6). The floors of the muri appear smooth. Cingulum and sulcus clearly delineated by the sutural septa; cingulum broad (5 mm) and typically subdivided, though seldom clearly.
Dimensions. Overall length = 28 (36) 45 µm (77 measurements); breadth at widest point = 30 (35) 40 µm (11 measurements).
Comparison. The ornamentation of Graptodinium inconditum sp. nov. comprises discontinuous ridges and isolated granules, as opposed to the fullydeveloped reticulum of Graptodinium omnireticulatum sp. nov. Both taxa exhibit a range of morphologies which are quite distinct at their mid-points in the samples examined as part of this study, though some intermediate specimens are less easy to classify.
Distribution. Representative occurrences, with emphasis on New Zealand, are listed in Table 1. Two other possible occurrences deserve mention: firstly, some of the forms described from the Eocene of Western Siberia by Tamara F. Vozzhennikova (Vozzhennikova 1967, p. 96–97, pl. 37, figs. 2–5; Lentin & Vozzhennikova 1990, p. 107–108), particularly Microdinium reticulatum Vozzhennikova 1967, appear somewhat similar to Graptodinium gen. nov. Unfortunately these illustrations do not permit assignment to either of the species described herein, and the Siberian type material has been lost. Secondly, Askin (1988) illustrated an apparently similar form from the Early Palaeocene of Seymour Island. If confirmed this occurrence would represent the most southerly and, by a considerable margin, the oldest record of Graptodinium inconditum sp. nov. With or without these uncertain records, Graptodinium inconditum sp. nov. is apparently cosmopolitan, having been reported from Spitsbergen (Head & Norris 1989) to the Falkland Plateau (Goodman & Ford 1983). Graptodinium inconditum sp. nov. may first occur in the Heretaungan (Early Lutetian) of New Zealand (Erica Crouch, personal communication). The oldest specimens studied by the present author are from the lower part of the Hampton Beach section, and are of Late Porangan to Early Bortonian (Middle to Late Lutetian) age. The oldest reported occurrence may be from the Lutetian of Ocean Drilling Program (ODP) Leg 105, in the Labrador Sea (Head & Norris 1989), or possibly, if the Seymour Island material does prove to be conspecific, from the Early Palaeocene of the northeastern Antarctic Peninsula (Askin 1988). The youngest presently known occurrence is from the Late Whaingaroan (Rupelian to Chattian) Chalky Island Formation, Fiordland, New Zealand (Wilson 1982a).
Holotype: Clowes, 2013, pl.1, figs.1–3.
Age: Lutetian–Chattian.
Original description: Clowes, 2013
Graptodinium inconditum sp. nov. Plate 1, figures 1–6; Plate 2, figures 1–12
Synonyms:
Microdinium sp. 1; Châteauneuf 1980, p. 143, pl. 26, figs. 5–7.
Corrudinium sp.; Wilson 1982a, pl. 1, fig. 6.
Histiocysta sp.; Goodman & Ford 1983, pl. 9, figs. 7–8.
Histiocysta sp.; Clowes & Morgans 1984, p. 32, pl. 2, fig. 3.
Microdinium sp. 1 of Châteauneuf; Edwards 1984, pl. 2, fig. 6.
Histiocysta sp.; Wilson 1985, p. 99, pl. 1, fig. 8.
Microdinium reticulatum Vozzhennikova 1967; De Coninck 1986, p. 16, pl. 6, figs. 1–7, pl. 7, figs.14–16.
Histiocysta spp. of Goodman and Ford, 1983; Head & Norris 1989, p. 530, pl. 3, figs. 5–9.
Histiocysta sp.; Brinkhuis 1992, pl. 17, figs. 12–14.
Histiocysta sp.; Stover & Hardenbol 1994, p. 32, pl. 2, figs. 13–14.
Microdinium sp. 1 of Châteauneuf (1980); Schiøler 2005, pl. 17, figs. 14–15.
Holotype. Specimen L16341/SM4946, Plate 1, figs. 1–3; sample I43/f093, Burnside Formation, Puketeraki core 45.90–45.85 m (Wilson & McMillan 1996, p. 15, 54–58; note that core measurements cited therein commence from the base of the core), Dunedin, New Zealand, grid ref. I43/2655 0313; Upper Bortonian– Kaiatan Stage (Bartonian–Priabonian). Overall length = 40 µm (excludes displaced operculum), breadth = 40 µm at widest point (posterior suture of cingulum), height of sutural septa = 4.5 µm at antapex.
Paratypes. Specimen L16341/SM4945 (Plate 1, figures 4–6); specimen L16341/SM4943 (Plate 2, figures 1–6); specimen L16341/SM4947 (Plate 2, figures 7, 8); specimen L16341/SM4944 (Plate 2, figure 9). All paratypes from sample I43/f093, Burnside Formation, Puketeraki core 45.90–45.85 m, Dunedin, New Zealand, grid ref. I43/2655 0313; Upper Bortonian–Kaiatan Stage (Bartonian–Priabonian).
Derivation of name. From the Latin inconditus, meaning irregular, with reference to the intratabular ornamentation.
Description. Cysts small, proximate, subspherical to slightly prolate, lacking horns; the epicyst somewhat or, more usually, considerably smaller than the hypocyst. Cyst walls apparently single-layered. Archaeopyle apical, type (tA); operculum free or, more commonly, attached. Processes lacking; ornament comprising low, solid sutural and intratabular septa. Sutural septa approximately 2.5 to 4.5 mm high, particularly distinct in equatorial view, forming a well-defined cladopyxiacean tabulation, ?4’, ?0a, 6’’, 6c, 6’’’, 1p, 1’’’’. Accessory septa comprising the irregular intratabular ornament forming an incomplete reticulum, sometimes continuous with the sutural septa, sometimes separated by a narrow clear area (Plate 1, figures 1, 6). The floors of the muri appear smooth. Cingulum and sulcus clearly delineated by the sutural septa; cingulum broad (5 mm) and typically subdivided, though seldom clearly.
Dimensions. Overall length = 28 (36) 45 µm (77 measurements); breadth at widest point = 30 (35) 40 µm (11 measurements).
Comparison. The ornamentation of Graptodinium inconditum sp. nov. comprises discontinuous ridges and isolated granules, as opposed to the fullydeveloped reticulum of Graptodinium omnireticulatum sp. nov. Both taxa exhibit a range of morphologies which are quite distinct at their mid-points in the samples examined as part of this study, though some intermediate specimens are less easy to classify.
Distribution. Representative occurrences, with emphasis on New Zealand, are listed in Table 1. Two other possible occurrences deserve mention: firstly, some of the forms described from the Eocene of Western Siberia by Tamara F. Vozzhennikova (Vozzhennikova 1967, p. 96–97, pl. 37, figs. 2–5; Lentin & Vozzhennikova 1990, p. 107–108), particularly Microdinium reticulatum Vozzhennikova 1967, appear somewhat similar to Graptodinium gen. nov. Unfortunately these illustrations do not permit assignment to either of the species described herein, and the Siberian type material has been lost. Secondly, Askin (1988) illustrated an apparently similar form from the Early Palaeocene of Seymour Island. If confirmed this occurrence would represent the most southerly and, by a considerable margin, the oldest record of Graptodinium inconditum sp. nov. With or without these uncertain records, Graptodinium inconditum sp. nov. is apparently cosmopolitan, having been reported from Spitsbergen (Head & Norris 1989) to the Falkland Plateau (Goodman & Ford 1983). Graptodinium inconditum sp. nov. may first occur in the Heretaungan (Early Lutetian) of New Zealand (Erica Crouch, personal communication). The oldest specimens studied by the present author are from the lower part of the Hampton Beach section, and are of Late Porangan to Early Bortonian (Middle to Late Lutetian) age. The oldest reported occurrence may be from the Lutetian of Ocean Drilling Program (ODP) Leg 105, in the Labrador Sea (Head & Norris 1989), or possibly, if the Seymour Island material does prove to be conspecific, from the Early Palaeocene of the northeastern Antarctic Peninsula (Askin 1988). The youngest presently known occurrence is from the Late Whaingaroan (Rupelian to Chattian) Chalky Island Formation, Fiordland, New Zealand (Wilson 1982a).