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Valvaeodinium hirsutum
From Fensome et al., 2019:
Valvaeodinium hirsutum Bucefalo Palliani and Riding, 1997a, p.202,204, pl.1, figs.10–12; text-figs.9A–B.
Holotype: Bucefalo Palliani and Riding, 1997a, pl.1, fig.10.
Age: early Toarcian.
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Original description (Bucefalo Palliani and Riding, 1997a):
Valvaeodinium hirsutum sp. nov. Plate 1, figs. 10-12, Text-Figure 9
Holotype. Slide PO 3.60 (3), England Finder coordinate N19/4 (Plate 1, fig. 10). Length 33 µm, width 23 µm, average length of spines 6 µm.
Repository. Department of Earth Sciences, University of Perugia, Italy.
Type Locality. Pozzale section, sample PO 3.60,3.60 m from the base, Marne di Monte Serrone Formation, central Italy.
Stratigraphic Horizon. Lower Jurassic, lower Toarcian, middle part of the D. tenuicostatum Zone. The stratigraphic range is between the first occurrences of calcareous nannofossils Carinolithus superbus (Deflandre 1954)Prins in Griin et al., 1974 and Discorhabdus ignotus.
Derivatio Nominis. From the numerous hair-like spines arising from the cyst.
Diagnosis. Ellipsoidal, proximochorate, acavate small dinoflagellate cysts. Autophragm microscabrate, ornamented by non-tabular solid homomorphic spines. Archeopyle is of combination apical/intercalary type (Type 1A+1I).
Description. Subspherical to elongate ellipsoidal, proximochorate, acavate dinoflagellate cysts (Text-Figure 9). Size is generally less than 50 µm (i.e. "small" of Stover and Evitt, 1978 p. 5). Autophragm thin, microscabrate, ornamented by nontabular solid, straight, tapering spines, with acuminate or oblate tips. On each cyst the spines are homomorphic. Archeopyle is of combination apical/intercalary type (Type 1A+1I). Paracingulum indicated by an extensive equatorial area which has rare, randomly inserted spines. Epicyst and hypocyst equal in size. Overall length of cyst: minimum 23 µm, mean 27 µ, maximum 32 µm. Overall width of cyst: minimum 20 µm, mean 21 µm, maximum 23 µm. Length of spines: minimum 3 µm, mean 6 µm, maximum 9 µm (22 specimens measured).
Discussion. Valvaeodiniumarmatum (Morgenroth 1970) Below 1987 is larger than V. hirsutum and has a granulate autophragm with parasutural features. Moreover, in V. armatum, spines are present only within the paraplates and are basally branched and distally bi- tri- and polyfurcate or cauliflorate. Valvaeodinium koessenium (Morbey 1975) Below 1987 differs from V. hirsutum by the presence of intratabular and/or parasutural processes and a smooth paracingular area. Valvaeodinium hirsutum resembles Valvaeodinium stipulatum (Wille & Gocht 1979) Below 1987 in having nontabular processes; however, in V. stipulatum the processes are distally rounded, whereas in V. hirsutum the processes are conical, with acuminate or oblate tips. Valvaeodinium hirsutum has been recorded in Lefkas Island (northwest Greece) and the Umbria-Marche area (central Italy).
Valvaeodinium hirsutum Bucefalo Palliani and Riding, 1997a, p.202,204, pl.1, figs.10–12; text-figs.9A–B.
Holotype: Bucefalo Palliani and Riding, 1997a, pl.1, fig.10.
Age: early Toarcian.
---------------------------------------------------------------------------------------------------
Original description (Bucefalo Palliani and Riding, 1997a):
Valvaeodinium hirsutum sp. nov. Plate 1, figs. 10-12, Text-Figure 9
Holotype. Slide PO 3.60 (3), England Finder coordinate N19/4 (Plate 1, fig. 10). Length 33 µm, width 23 µm, average length of spines 6 µm.
Repository. Department of Earth Sciences, University of Perugia, Italy.
Type Locality. Pozzale section, sample PO 3.60,3.60 m from the base, Marne di Monte Serrone Formation, central Italy.
Stratigraphic Horizon. Lower Jurassic, lower Toarcian, middle part of the D. tenuicostatum Zone. The stratigraphic range is between the first occurrences of calcareous nannofossils Carinolithus superbus (Deflandre 1954)Prins in Griin et al., 1974 and Discorhabdus ignotus.
Derivatio Nominis. From the numerous hair-like spines arising from the cyst.
Diagnosis. Ellipsoidal, proximochorate, acavate small dinoflagellate cysts. Autophragm microscabrate, ornamented by non-tabular solid homomorphic spines. Archeopyle is of combination apical/intercalary type (Type 1A+1I).
Description. Subspherical to elongate ellipsoidal, proximochorate, acavate dinoflagellate cysts (Text-Figure 9). Size is generally less than 50 µm (i.e. "small" of Stover and Evitt, 1978 p. 5). Autophragm thin, microscabrate, ornamented by nontabular solid, straight, tapering spines, with acuminate or oblate tips. On each cyst the spines are homomorphic. Archeopyle is of combination apical/intercalary type (Type 1A+1I). Paracingulum indicated by an extensive equatorial area which has rare, randomly inserted spines. Epicyst and hypocyst equal in size. Overall length of cyst: minimum 23 µm, mean 27 µ, maximum 32 µm. Overall width of cyst: minimum 20 µm, mean 21 µm, maximum 23 µm. Length of spines: minimum 3 µm, mean 6 µm, maximum 9 µm (22 specimens measured).
Discussion. Valvaeodiniumarmatum (Morgenroth 1970) Below 1987 is larger than V. hirsutum and has a granulate autophragm with parasutural features. Moreover, in V. armatum, spines are present only within the paraplates and are basally branched and distally bi- tri- and polyfurcate or cauliflorate. Valvaeodinium koessenium (Morbey 1975) Below 1987 differs from V. hirsutum by the presence of intratabular and/or parasutural processes and a smooth paracingular area. Valvaeodinium hirsutum resembles Valvaeodinium stipulatum (Wille & Gocht 1979) Below 1987 in having nontabular processes; however, in V. stipulatum the processes are distally rounded, whereas in V. hirsutum the processes are conical, with acuminate or oblate tips. Valvaeodinium hirsutum has been recorded in Lefkas Island (northwest Greece) and the Umbria-Marche area (central Italy).