Back
Cribroperidinium colum
From Fensome et al., 2019:
Cribroperidinium colum Duxbury, 2001, p.103–104, fig.5, nos.1–4. Holotype: Duxbury, 2001, fig.5, nos.1–2. NIA. Age: late Hauterivian–middle Barremian.
---------------------------------------------------------------------------------------------------
Original description (Duxbury, 2001):
Cribroperidinium colum n. sp.
Holotype: Figures 5.1, 5.2.
Type Locality: Well 13/24 a-4 at 5730 ft (ditch cuttings), Middle Barremian. E.F. U23.2.
Derivation of Name: From the Latin colum, a sieve, strainer - in reference to the perforate cyst wall.
Diagnosis: A small, thin-walled, spheroidal dinocyst species which possesses a short, solid apical projection. The epicyst and hypocyst are of
approximately equal length, and the former tapers sharply towards the apex.
Typical gonyaulacacean paratabulation is outlined by low ridges. The entire cyst is perforate, with perforations varying significantly in size between specimens, and sometimes in individual specimens; individual perforations can be as large as 5 μm. The archeopyle is formed by detachment of paraplate 3".
Dimensions: Holotype: 60 x 53 μm
Overall: 89 (76) 60 x 83 (68) 53 μm
Specimens Measured – 11
Comments: Cribroperidinium colum n. Sp. differs from all other species of this genus in its distinctive, perforate cyst wall. Other species of Cribroperidinium NEALE & SARJEANT, 1962 display perforate walls, most notably C. confossum (DUXBURY, 1977) HELENES, 1984. However, the last species is much larger than C. colum n. sp., with a very long apical horn and smaller, denser perforations. This species is restricted to the Middle Barremian to Late Hauterivian interval and, although it is consistently present, it tends to be rare.
Cribroperidinium colum Duxbury, 2001, p.103–104, fig.5, nos.1–4. Holotype: Duxbury, 2001, fig.5, nos.1–2. NIA. Age: late Hauterivian–middle Barremian.
---------------------------------------------------------------------------------------------------
Original description (Duxbury, 2001):
Cribroperidinium colum n. sp.
Holotype: Figures 5.1, 5.2.
Type Locality: Well 13/24 a-4 at 5730 ft (ditch cuttings), Middle Barremian. E.F. U23.2.
Derivation of Name: From the Latin colum, a sieve, strainer - in reference to the perforate cyst wall.
Diagnosis: A small, thin-walled, spheroidal dinocyst species which possesses a short, solid apical projection. The epicyst and hypocyst are of
approximately equal length, and the former tapers sharply towards the apex.
Typical gonyaulacacean paratabulation is outlined by low ridges. The entire cyst is perforate, with perforations varying significantly in size between specimens, and sometimes in individual specimens; individual perforations can be as large as 5 μm. The archeopyle is formed by detachment of paraplate 3".
Dimensions: Holotype: 60 x 53 μm
Overall: 89 (76) 60 x 83 (68) 53 μm
Specimens Measured – 11
Comments: Cribroperidinium colum n. Sp. differs from all other species of this genus in its distinctive, perforate cyst wall. Other species of Cribroperidinium NEALE & SARJEANT, 1962 display perforate walls, most notably C. confossum (DUXBURY, 1977) HELENES, 1984. However, the last species is much larger than C. colum n. sp., with a very long apical horn and smaller, denser perforations. This species is restricted to the Middle Barremian to Late Hauterivian interval and, although it is consistently present, it tends to be rare.