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Ctenidodinium chondrum
Ctenodinium? chondrum Drugg, 1978
Now Dichadogonyaulax. Originally Ctenidodinium, subsequently Ctenidodinium?, thirdly (and now) Dichadogonyaulax.
Woollam, 1983, considered this to be a provisionally accepted species of Ctenidodinium.
Holotype: Drugg, 1978, pl.1, fig.10
Paratypes: Drugg, 1978
Locus typicus: Octeville, Normandy, France
Stratum typicum: Early Kimmeridgian
Original description: Drugg, 1978, p. 66.
Oblate cyst with a gonyaulacoid paratabulation. A low fuzzy apical projection is sometimes present. The wall is thin and finely granulate. Often the grana are arranged so as to from a crude microreticulum with lumina from 1 to 2 Ám across. The parasutures are low but distinct. The paratabulation of the epicyst is 1 pr, 4", 6"". Paraplate 4" lies above paraplate 6"" and 1" lies above an anterior sulcal paraplate. Both 1" and 4" are quite elongate and they are juxtaposed. Paraplate 6"" is quite small and is juxtaposed to the anterior sulcal paraplate which is about the same size. The paracingulum is about 4 Ám wide and is composed of 6 paraplates. The paratabulation of the hypocyst has not been seen in optimum orientation but is apparently 6""", 1p, 1"""". The archeopyle is epicystal with the line of separation occurring just anterior to the paracingulum. The cyst height ranges from 55 to 80 Ám and the width from 70 to 95 Ám. Size range based on measurement 14 specimens.
Affinities:
Drugg, 1978, p. 66
This species resembles C. pachydermum (Deflandre) Gocht, 1970, to the extent that both exhibit low parasutural crests. However the wall of C. chondrum is thin whereas that of C. pachydermum is thick. Furthermore the shape of C. chondrum is oblate as opposed to the more or less spheroidal shape of C. pachydermum. All other described species of Ctenodinium exhibit relatively high and ornate parasutural crests.
Now Dichadogonyaulax. Originally Ctenidodinium, subsequently Ctenidodinium?, thirdly (and now) Dichadogonyaulax.
Woollam, 1983, considered this to be a provisionally accepted species of Ctenidodinium.
Holotype: Drugg, 1978, pl.1, fig.10
Paratypes: Drugg, 1978
Locus typicus: Octeville, Normandy, France
Stratum typicum: Early Kimmeridgian
Original description: Drugg, 1978, p. 66.
Oblate cyst with a gonyaulacoid paratabulation. A low fuzzy apical projection is sometimes present. The wall is thin and finely granulate. Often the grana are arranged so as to from a crude microreticulum with lumina from 1 to 2 Ám across. The parasutures are low but distinct. The paratabulation of the epicyst is 1 pr, 4", 6"". Paraplate 4" lies above paraplate 6"" and 1" lies above an anterior sulcal paraplate. Both 1" and 4" are quite elongate and they are juxtaposed. Paraplate 6"" is quite small and is juxtaposed to the anterior sulcal paraplate which is about the same size. The paracingulum is about 4 Ám wide and is composed of 6 paraplates. The paratabulation of the hypocyst has not been seen in optimum orientation but is apparently 6""", 1p, 1"""". The archeopyle is epicystal with the line of separation occurring just anterior to the paracingulum. The cyst height ranges from 55 to 80 Ám and the width from 70 to 95 Ám. Size range based on measurement 14 specimens.
Affinities:
Drugg, 1978, p. 66
This species resembles C. pachydermum (Deflandre) Gocht, 1970, to the extent that both exhibit low parasutural crests. However the wall of C. chondrum is thin whereas that of C. pachydermum is thick. Furthermore the shape of C. chondrum is oblate as opposed to the more or less spheroidal shape of C. pachydermum. All other described species of Ctenodinium exhibit relatively high and ornate parasutural crests.