Back
Sophismatia exouros
From Fensome et al., 2019:
Sophismatia ?exouros (Islam, 1983c, p.88, pl.3, figs.3–4) Williams et al., 2015, p.313. Holotype: Islam, 1983c, pl.3, fig.3. Originally Kisselevia tenuivirgula subsp. exouros, subsequently Charlesdowniea tenuivirgula subsp. exouros, thirdly (and now) Sophismatia? exouros. Questionable assignment: Williams et al. (2015, p.313). Age: Middle Eocene.
---------------------------------------------------------------------------------------------------
Original description [Islam, 1983c]:
Kisselovia tenuivirgula subsp. exouros n. ssp.
Plate 3, figures 3-4.
Derivation of name. Gk. exouros - ending in a tail; refers to its single antapical horn.
Diagnosis. Pericyst dorsoventrally compressed peridinioid with an apical, two paracingular and one antapical horns, thus assuming a more or less rhomboidal outline; endocyst rounded rhomboidal, generally lying close to and following epicyst ambitus; identical to K. tenuivirgula (Williams & Downie) Lentin & Williams 1976 but differ in possessing only one antapical horn.
Holotype. Slide C1745(2),N28.1; Middle Bagshot Member, Middle Eocene, Shapley Heath.
Paratype. Slide C1745(4),H44.2.
Dimensions. Holotype: pericyst 110 x 110 μm, length of processes 5-10 μm. Range: pericyst length 73 (94) 110 μm, breadth 62 (92) 110 μm, length of processes 5-12 μm. Specimens measured 10.
Occurrence. Shapley Heath: C1760 - C1745; Isle of Sheppey: S14 - S5.
Remarks. Most Kisselovia species show the tendency to reduce to one antapical horn and it seems possible that this tendency has a phyletic significance.
Sophismatia ?exouros (Islam, 1983c, p.88, pl.3, figs.3–4) Williams et al., 2015, p.313. Holotype: Islam, 1983c, pl.3, fig.3. Originally Kisselevia tenuivirgula subsp. exouros, subsequently Charlesdowniea tenuivirgula subsp. exouros, thirdly (and now) Sophismatia? exouros. Questionable assignment: Williams et al. (2015, p.313). Age: Middle Eocene.
---------------------------------------------------------------------------------------------------
Original description [Islam, 1983c]:
Kisselovia tenuivirgula subsp. exouros n. ssp.
Plate 3, figures 3-4.
Derivation of name. Gk. exouros - ending in a tail; refers to its single antapical horn.
Diagnosis. Pericyst dorsoventrally compressed peridinioid with an apical, two paracingular and one antapical horns, thus assuming a more or less rhomboidal outline; endocyst rounded rhomboidal, generally lying close to and following epicyst ambitus; identical to K. tenuivirgula (Williams & Downie) Lentin & Williams 1976 but differ in possessing only one antapical horn.
Holotype. Slide C1745(2),N28.1; Middle Bagshot Member, Middle Eocene, Shapley Heath.
Paratype. Slide C1745(4),H44.2.
Dimensions. Holotype: pericyst 110 x 110 μm, length of processes 5-10 μm. Range: pericyst length 73 (94) 110 μm, breadth 62 (92) 110 μm, length of processes 5-12 μm. Specimens measured 10.
Occurrence. Shapley Heath: C1760 - C1745; Isle of Sheppey: S14 - S5.
Remarks. Most Kisselovia species show the tendency to reduce to one antapical horn and it seems possible that this tendency has a phyletic significance.