Back
Phthanoperidinium bennettii
Phtanoperidinium bennettii Matsuoka and Bujak, 1988
Holotype: Matsuoka and Bujak. 1988, pl.9, fig.4; text-fig.13a-b
Paratype: Matsuoka and Bujak, 1988
Locus typicus: Navarin Basin COST No. 1 Well, 12740-12750ft, Navarin Basin, Bering Sea
Stratum typicum: Early Oligocene
Original diagnosis: Matsuoka and Bujak, 1988, p.66
Small to intermediate proximate cyst with an ovoidal to roundly hexagonal shape. Epicyst roundly pentagonal in dorsoventral view, always larger than hypocyst and bearing a small apical horn; hypocyst truncated, possessing two small asymmetrical antapical horns. Cyst wall comprising psilate to granulate periphragm, and thick and smooth endophragm. Paratabulation clearly defined as 4", 3a, 7", 6c (?), 5""", 0p, 2"""", xs by low and smooth parasutural crests. Paraplate 2a iso- to lati-theta form, forming the intercalary archeopyle. Paracingulum displaced in half of its width. Parasulcus wide, shallow and almost straight, extending deeply onto both of epi- and hyprocysts.
Original description: Matsuoka and Bujak, 1988, p.67
The proximate cyst comprises a periphragm and endophragm which are mostly adpressed. The periphragm is relatively thin, psilate to granulate, and the endophragm is thick and smooth. The epicyst is convexly conical with a short blunt or rounded apical horn. The hypocyst possesses two very small and asymmetrical antapical horns, the right antapical horn always being reduced. Parasutures are represented by low smooth crests without distal ornament. The paratabulation of 4", 3a, 7", 6c(?), 5""", 2"""", and xs is well defined. Paraplate 1" is pentagonal and contacts paraplates 2", 4", 1", 7" and the anterior sulcal paraplates. The 2a paraplate is iso- to lati-thetaform (hexagonal). The paracingulum is laevorotary and the cingular paraplates may be obscure because the paracingulum is narrow and often deformed. The parasulcus is wide and extends deeply onto the epicyst and hypocyst. The parasuture between the sulcus and the first apical paraplate is well developed. An archeopyle is formed by the loss of paraplate 2a. Dimensions: Holotype; length of cyst 56 µm, width 49 µm, height of antapical horn 2.8 µm, width of paracingulum 6 µm. Range; length of cyst 44-56 µm, width 40-53 µm, height of antapical horn 1-3 µm, width of paracingulum 5-6 µm. Number of specimens measured; 10. Thecal affinity: P. benettii is attributable to the Peridinioid lineage based on its paratabulation.
Affinities:
Matsuoka and Bujak, 1988, p.67: Phthanoperidinium benettii differs from other species of Phthanoperidinium in having a broad sulcus and an epicyst which is much larger than the hypocyst.
Holotype: Matsuoka and Bujak. 1988, pl.9, fig.4; text-fig.13a-b
Paratype: Matsuoka and Bujak, 1988
Locus typicus: Navarin Basin COST No. 1 Well, 12740-12750ft, Navarin Basin, Bering Sea
Stratum typicum: Early Oligocene
Original diagnosis: Matsuoka and Bujak, 1988, p.66
Small to intermediate proximate cyst with an ovoidal to roundly hexagonal shape. Epicyst roundly pentagonal in dorsoventral view, always larger than hypocyst and bearing a small apical horn; hypocyst truncated, possessing two small asymmetrical antapical horns. Cyst wall comprising psilate to granulate periphragm, and thick and smooth endophragm. Paratabulation clearly defined as 4", 3a, 7", 6c (?), 5""", 0p, 2"""", xs by low and smooth parasutural crests. Paraplate 2a iso- to lati-theta form, forming the intercalary archeopyle. Paracingulum displaced in half of its width. Parasulcus wide, shallow and almost straight, extending deeply onto both of epi- and hyprocysts.
Original description: Matsuoka and Bujak, 1988, p.67
The proximate cyst comprises a periphragm and endophragm which are mostly adpressed. The periphragm is relatively thin, psilate to granulate, and the endophragm is thick and smooth. The epicyst is convexly conical with a short blunt or rounded apical horn. The hypocyst possesses two very small and asymmetrical antapical horns, the right antapical horn always being reduced. Parasutures are represented by low smooth crests without distal ornament. The paratabulation of 4", 3a, 7", 6c(?), 5""", 2"""", and xs is well defined. Paraplate 1" is pentagonal and contacts paraplates 2", 4", 1", 7" and the anterior sulcal paraplates. The 2a paraplate is iso- to lati-thetaform (hexagonal). The paracingulum is laevorotary and the cingular paraplates may be obscure because the paracingulum is narrow and often deformed. The parasulcus is wide and extends deeply onto the epicyst and hypocyst. The parasuture between the sulcus and the first apical paraplate is well developed. An archeopyle is formed by the loss of paraplate 2a. Dimensions: Holotype; length of cyst 56 µm, width 49 µm, height of antapical horn 2.8 µm, width of paracingulum 6 µm. Range; length of cyst 44-56 µm, width 40-53 µm, height of antapical horn 1-3 µm, width of paracingulum 5-6 µm. Number of specimens measured; 10. Thecal affinity: P. benettii is attributable to the Peridinioid lineage based on its paratabulation.
Affinities:
Matsuoka and Bujak, 1988, p.67: Phthanoperidinium benettii differs from other species of Phthanoperidinium in having a broad sulcus and an epicyst which is much larger than the hypocyst.