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Dinogymnium heterocostatum
Dinogymnium heterocostatum (Deflandre, 1935) Evitt et al., 1967
Originally Gvmnodinium, subsequently (and now) Dinogymnium.
Holotype: Deflandre, 1935, text-fie.6
Age: ?Senonian
Comment: Evit, Clarke and Verdier 1967, p. 19-20
This species resembles D. acuminatum in important respects but, for reasons given in the discussion of that species, it is presently impossible to determine whether they are conspecific, and it seems best to treat them as distinct species. The features of the holotype, which is from a chert pebble of uncertainly Senonian age, have been thoroughly described by Deflandre and reviewed in this paper in connection with D. acuminatum. A specimen of known Senonian age, figured by Deflandre in I943, is closely similar to the holotype. The illustrations of the single specimen from the Maastrichtian of Belgium (Lejeune-Carpentier, 1951) may represent the same species but the specimen is apparently somewhat distorted, as well as being obliquely oriented in chert, so that its features can only partly be seen. The cingulum is described as showing "un certain nombre de barres transversales," features not otherwise reported for the species. The reported occurrence of specimens in the German Turonian that can be compared with this species (Alberti, 1961) is not accompanied by an illustration or description that would permit further comment on their identification. A difference in size--the German specimens being larger than the holotype--apparently explains Alberti"s use of "cf." in the specific attribution. Specific identification of the two specimens from the Senonian of Australia that were compared to this species by Deflandre and Cookson (1955) and later referred to D. westralium by Cookson and Eisenack (1958) cannot be confirmed on the basis of published information. The single published illustration does not seem to show either the pustulate surface seemingly present in the holotype of D. westralium or the granulate surface of the holotype of D. heterocostatum. The reported characteristics of size and shape do not seem adequate either to ally these specimens with one of these species, or to differentiate them from D. cretaceum as suggested by Deflandre and Cookson.
This species is also figures as (synonym list):
Gymnodinium heterocostatum DEFLANDRE, Ig3sb, Bull. Biol. France Belgique, vol. 69, p. 225-26, text-fig. 6 (nomen nudum; Senonian?, France); DEFLANDRE, Ig36a, Les Flagelles fossiles, Actual. scient. et ind., no. 335, p. 59, text-fig. 93 (nomen nudum; copy of original illustration); DEFLANDRE, Ig36b, Ann. Paleont., vol. 25, p. I65-66, pl. I2, fig. 6 (first description; copy of original illustration); DEFLANDRE, 1943, Soc. Geol. Fr., Bull., ser. 5, vol. r3, text-fig. I0 (no text; illustration of specimen from another locality; Senonian, France); LEJEUNE-CARPENTIER, 195I, Soc. Geol. Belgique, Ann., vol. 74, p. B308-30g, text-fig. 2 (Maastrichtian, Belgium); DEFLANDRE, Igs2a, Traite de Zoologie, vol. I, text-fig. 30rE (no text; copy of original figure); EISENACK, I964, Katalog der fossilen Dinoflagellaten, etc., vol. 1, p. 431-32 (with copy of original il- lustration); DOWNIE & SARJEANT, I964 (I965), Geol. Soc. America, Mem. 94, p. II6 (bibl. ref. only); G. & M. DEFLANDRE, I966, Fichier Micropaleont. Gen., ser. 15, card 2926 (no text; copies of illustrations from Deflandre, 1935, Ig36b, 1943, plus two new photomicrographs of holotype), card 2927 (no text, copy of illustration from Lejeune-Carpentier, 1951).
Originally Gvmnodinium, subsequently (and now) Dinogymnium.
Holotype: Deflandre, 1935, text-fie.6
Age: ?Senonian
Comment: Evit, Clarke and Verdier 1967, p. 19-20
This species resembles D. acuminatum in important respects but, for reasons given in the discussion of that species, it is presently impossible to determine whether they are conspecific, and it seems best to treat them as distinct species. The features of the holotype, which is from a chert pebble of uncertainly Senonian age, have been thoroughly described by Deflandre and reviewed in this paper in connection with D. acuminatum. A specimen of known Senonian age, figured by Deflandre in I943, is closely similar to the holotype. The illustrations of the single specimen from the Maastrichtian of Belgium (Lejeune-Carpentier, 1951) may represent the same species but the specimen is apparently somewhat distorted, as well as being obliquely oriented in chert, so that its features can only partly be seen. The cingulum is described as showing "un certain nombre de barres transversales," features not otherwise reported for the species. The reported occurrence of specimens in the German Turonian that can be compared with this species (Alberti, 1961) is not accompanied by an illustration or description that would permit further comment on their identification. A difference in size--the German specimens being larger than the holotype--apparently explains Alberti"s use of "cf." in the specific attribution. Specific identification of the two specimens from the Senonian of Australia that were compared to this species by Deflandre and Cookson (1955) and later referred to D. westralium by Cookson and Eisenack (1958) cannot be confirmed on the basis of published information. The single published illustration does not seem to show either the pustulate surface seemingly present in the holotype of D. westralium or the granulate surface of the holotype of D. heterocostatum. The reported characteristics of size and shape do not seem adequate either to ally these specimens with one of these species, or to differentiate them from D. cretaceum as suggested by Deflandre and Cookson.
This species is also figures as (synonym list):
Gymnodinium heterocostatum DEFLANDRE, Ig3sb, Bull. Biol. France Belgique, vol. 69, p. 225-26, text-fig. 6 (nomen nudum; Senonian?, France); DEFLANDRE, Ig36a, Les Flagelles fossiles, Actual. scient. et ind., no. 335, p. 59, text-fig. 93 (nomen nudum; copy of original illustration); DEFLANDRE, Ig36b, Ann. Paleont., vol. 25, p. I65-66, pl. I2, fig. 6 (first description; copy of original illustration); DEFLANDRE, 1943, Soc. Geol. Fr., Bull., ser. 5, vol. r3, text-fig. I0 (no text; illustration of specimen from another locality; Senonian, France); LEJEUNE-CARPENTIER, 195I, Soc. Geol. Belgique, Ann., vol. 74, p. B308-30g, text-fig. 2 (Maastrichtian, Belgium); DEFLANDRE, Igs2a, Traite de Zoologie, vol. I, text-fig. 30rE (no text; copy of original figure); EISENACK, I964, Katalog der fossilen Dinoflagellaten, etc., vol. 1, p. 431-32 (with copy of original il- lustration); DOWNIE & SARJEANT, I964 (I965), Geol. Soc. America, Mem. 94, p. II6 (bibl. ref. only); G. & M. DEFLANDRE, I966, Fichier Micropaleont. Gen., ser. 15, card 2926 (no text; copies of illustrations from Deflandre, 1935, Ig36b, 1943, plus two new photomicrographs of holotype), card 2927 (no text, copy of illustration from Lejeune-Carpentier, 1951).