Back
Impletosphaeridium insolitum
Impletosphaeridium insolitum Eaton, 1976
Originally (and now) Impletosphaeridium, subsequently Cleistosphaeridium?.
Islam, 1993, reverted this species to Impletosphaeridium, following the redundancy of Cleistoshpaeridium.
Holotype: Eaton, 1976, pl.21, fig.5; Bujak et al., 1980, pl.5, fig.5
Locus typicus: Bracklesham Beds, Whitecliff Bay, Isle of Wight, England.
Stratum typicum: Early-Middle Eocene
Original diagnosis: Eaton, 1976, p. 308
Cyst body spherical or subspherical, with a smooth or finely granular surface. Processes numerous, slender and solid. They are simple or bifurcate, with small bulbous spherical or subspherical distal terminations, and may be thickened by the development of proximal membrane; membrane may also be present in the angle of bifurcation.
Dimensions: Holotype: diameter of cyst body 22 µm; length of processes up to 9 µm. Observed range: diameter of cyst body 15-24 µm; length of processes up to 9 µm (n = 10).
Affinities:
Eaton, 1976, p. 308: Most specimens have simple and bifurcate processes but a few have been observed in which all the processes are simple. The point of bifurcation usually occurs within the distal half of the process. The cyst body occasionally shows a polygonal opening, but no other indications of reflected tabulation have been observed. The unusual form of the processes distinguishes I. insolitum from all other described species of Impletosphaeridium.
Originally (and now) Impletosphaeridium, subsequently Cleistosphaeridium?.
Islam, 1993, reverted this species to Impletosphaeridium, following the redundancy of Cleistoshpaeridium.
Holotype: Eaton, 1976, pl.21, fig.5; Bujak et al., 1980, pl.5, fig.5
Locus typicus: Bracklesham Beds, Whitecliff Bay, Isle of Wight, England.
Stratum typicum: Early-Middle Eocene
Original diagnosis: Eaton, 1976, p. 308
Cyst body spherical or subspherical, with a smooth or finely granular surface. Processes numerous, slender and solid. They are simple or bifurcate, with small bulbous spherical or subspherical distal terminations, and may be thickened by the development of proximal membrane; membrane may also be present in the angle of bifurcation.
Dimensions: Holotype: diameter of cyst body 22 µm; length of processes up to 9 µm. Observed range: diameter of cyst body 15-24 µm; length of processes up to 9 µm (n = 10).
Affinities:
Eaton, 1976, p. 308: Most specimens have simple and bifurcate processes but a few have been observed in which all the processes are simple. The point of bifurcation usually occurs within the distal half of the process. The cyst body occasionally shows a polygonal opening, but no other indications of reflected tabulation have been observed. The unusual form of the processes distinguishes I. insolitum from all other described species of Impletosphaeridium.