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Phelodinium
From Williams et al., 2017:
[Phelodinium, Stover and Evitt, 1978, p. 117–118; Emendation: Mao Shaozhi and Norris, 1988, p. 51–52.
Type species: originally as Deflandrea pentagonalis, Corradini, 1973 (pl.28, fig.3)] ; Phelodinium pentagonale, Stover and Evitt, 1978
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Original description: [Stover and Evitt, 1978]:
Synopsis:
Cysts proximate, typically cornucavate, compressed peridinioid, with short to long apical and antapical horns; paratabulation generally indicated by paracingulum and archeopyle only; later intercalary, Type I, typically with antapical margin close to paracingulum; archeopyle index 0.3 to 0.4.
Description:
Shape: Compressed peridinioid, normally with straight to concave sides except between antapical horns; horns short to long, tips narrowly rounded or pointed.
Wall relationships: Cysts typically cornucavate.
Wall features: No parasutural features. Endophragm and periphragm smooth or faintly ornamented, commonly folded, or wrinkled.
Paratabulation: Indicated by archeopyle only or by archeopyle and paracingulum.
Archeopyle: Intercalary, Type I (2a only); archeopyle index about o.3 - 0.4: archeopyle generally much narrower apically than antapically, and antapical margin close to paracingulum.
Paracingulum: Indicated at widest part of cyst by folds or by transverse ridges; paracingulum not indicated on some species.
Parasulcus: Generally not indicated.
Size: Large.
Affinities:
Phelodinium differs from Lejeunia in being cavate and in having a peridinioid outline with straight to concave sides. Lejeunia has an autophragm only, and its lateral margins are normally convex.
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Emended description:
Mao Shaozhi and Norris, 1988:
Diagnosis:
Cyst proximate, typically cornucavate, compressed peridinioid, subrhomboidal to pentagonal in ambital view. One apical and one or two antapical horns always present and usually pointed. Periphragm and endophragm smooth or with features of low relief; the former thinner than the latter. Endoblast slightly to strongly prominent at the bases of the three horns.
Pericoels typically small and narrow.
Cingulum always discernible, its margins being indicated by low ridges or folds.
Archeopyle intercalary, type (I), standard hexa 2a, typically with antapical margin close to the cingulum; AI 0.3 to 0.6.
Indications of tabulation, other than archeopyle and cingulum, absent.
The above-emended diagnosis of Phelodinium augments the information pertaining to the archeopyle. The archeopyle index of Phelodinium according to Stover and Evitt (1978, p.117) is 0.3 to 0.4. µm the present study, 30 specimens of Phelodinium were observed; these have the typical morphological features for Phelodinium but have an archeopyle index greater than 0.4 (usually 0.4 to 0.5, occasionally up to 0.6), the archeopyle being essentially of standard hexa style. Thus, the generic diagnosis is here extended to encompass such forms.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Phelodinium Stover and Evitt, 1978, emend. Mao Shaozhi and Norris, 1988. Mao Shaozhi and Norris (1988, p. 52) provided the following emendation for Phelodinium. Cyst proximate, typically cornucavate, compressed peridinioid, subrhomboidal to pentagonal in ambital view; One apical and one or two antapical horns always present and usually pointed. Periphragm and endophragm smooth or with features of low relief; the former thinner than the latter. Endoblast slightly to strongly prominent at the bases of the three horns. Pericoels typically small and narrow. Cingulum always discernible, its margins being indicated by low ridges or folds. Archeopyle intercalary, type (IF), standard hexa 2a, typically with antapical margin close to the cingulum. AI 0.3 to 0.6. Indications of tabulation, other than archeopyle and cingulum absent.
[Phelodinium, Stover and Evitt, 1978, p. 117–118; Emendation: Mao Shaozhi and Norris, 1988, p. 51–52.
Type species: originally as Deflandrea pentagonalis, Corradini, 1973 (pl.28, fig.3)] ; Phelodinium pentagonale, Stover and Evitt, 1978
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Original description: [Stover and Evitt, 1978]:
Synopsis:
Cysts proximate, typically cornucavate, compressed peridinioid, with short to long apical and antapical horns; paratabulation generally indicated by paracingulum and archeopyle only; later intercalary, Type I, typically with antapical margin close to paracingulum; archeopyle index 0.3 to 0.4.
Description:
Shape: Compressed peridinioid, normally with straight to concave sides except between antapical horns; horns short to long, tips narrowly rounded or pointed.
Wall relationships: Cysts typically cornucavate.
Wall features: No parasutural features. Endophragm and periphragm smooth or faintly ornamented, commonly folded, or wrinkled.
Paratabulation: Indicated by archeopyle only or by archeopyle and paracingulum.
Archeopyle: Intercalary, Type I (2a only); archeopyle index about o.3 - 0.4: archeopyle generally much narrower apically than antapically, and antapical margin close to paracingulum.
Paracingulum: Indicated at widest part of cyst by folds or by transverse ridges; paracingulum not indicated on some species.
Parasulcus: Generally not indicated.
Size: Large.
Affinities:
Phelodinium differs from Lejeunia in being cavate and in having a peridinioid outline with straight to concave sides. Lejeunia has an autophragm only, and its lateral margins are normally convex.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended description:
Mao Shaozhi and Norris, 1988:
Diagnosis:
Cyst proximate, typically cornucavate, compressed peridinioid, subrhomboidal to pentagonal in ambital view. One apical and one or two antapical horns always present and usually pointed. Periphragm and endophragm smooth or with features of low relief; the former thinner than the latter. Endoblast slightly to strongly prominent at the bases of the three horns.
Pericoels typically small and narrow.
Cingulum always discernible, its margins being indicated by low ridges or folds.
Archeopyle intercalary, type (I), standard hexa 2a, typically with antapical margin close to the cingulum; AI 0.3 to 0.6.
Indications of tabulation, other than archeopyle and cingulum, absent.
The above-emended diagnosis of Phelodinium augments the information pertaining to the archeopyle. The archeopyle index of Phelodinium according to Stover and Evitt (1978, p.117) is 0.3 to 0.4. µm the present study, 30 specimens of Phelodinium were observed; these have the typical morphological features for Phelodinium but have an archeopyle index greater than 0.4 (usually 0.4 to 0.5, occasionally up to 0.6), the archeopyle being essentially of standard hexa style. Thus, the generic diagnosis is here extended to encompass such forms.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Phelodinium Stover and Evitt, 1978, emend. Mao Shaozhi and Norris, 1988. Mao Shaozhi and Norris (1988, p. 52) provided the following emendation for Phelodinium. Cyst proximate, typically cornucavate, compressed peridinioid, subrhomboidal to pentagonal in ambital view; One apical and one or two antapical horns always present and usually pointed. Periphragm and endophragm smooth or with features of low relief; the former thinner than the latter. Endoblast slightly to strongly prominent at the bases of the three horns. Pericoels typically small and narrow. Cingulum always discernible, its margins being indicated by low ridges or folds. Archeopyle intercalary, type (IF), standard hexa 2a, typically with antapical margin close to the cingulum. AI 0.3 to 0.6. Indications of tabulation, other than archeopyle and cingulum absent.