Back
Piladinium
From Williams et al., 2017:
[Piladinium, Williams et al., 2015, p. 308–309
Type species: Kisselovia columna, Michoux, 1988 (pl.1, figs.2–3)]
Stratigraphic occurrence: Early Eocene (Ypresian) to Middle Eocene (?early Lutetian).
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Williams et al., 2015]:
Diagnosis:
Wetzelielloidean cysts with a latiepeliform archeopyle and pericyst with processes distally united by membranes (ectophragm).
Description:
Shape: Dorso-ventral outline of pericyst rhomboidal, horns weakly to moderately well developed.
Dorso-ventral outline of endocyst rounded to rhomboidal.
Wall structure: Periphragm moderately thick, ornamented with processes that tend to show alignment to sutures or may be marginally distributed; processes distally connected by membranes. Endophragm thin, smooth.
Pericoels: Cysts circumcavate to cornucavate.
Tabulation: Weakly to moderately delineated by the processes and possibly by ectophragmal membranes.
Archeopyle: Latiepeliform, with no or minimal extension into apical pericoel, operculum free. Endoarcheopyle of same size or smaller than periarcheopyle, operculum free.
Cingulum: may be expressed by single row of processes; sulcus devoid of processes.
Size: Intermediate to large.
Affinities/Discussion:
Other genera with latiepeliform archeopyles are Dracodinium, Petalodinium, Stichodinium and Kledodinium. The periphragm of Dracodinium has processes that are more or less uniform in distribution and distally free. Stichodinium also has distally free processes, but having a sutural or penitabular distribution. Petalodinium has a periphragm that is smooth or ornamented with features of low relief and more or less uniform distribution. Kledodinium has processes distally linked by trabeculae rather than membranes. Other wetzelielloidean genera with processes distally connected by membranes are Charlesdowniea and Talladinium, but these have equiepeliform and soleiform archeopyles, respectively. The holotype of Piladinium columna has a pericyst 121 μm long and 124 μm wide. The holotype of Piladinium edwardsii has a pericyst 96 μm long and 107 μm wide and an endocyst 50 μm long and 58 μm wide.
[Piladinium, Williams et al., 2015, p. 308–309
Type species: Kisselovia columna, Michoux, 1988 (pl.1, figs.2–3)]
Stratigraphic occurrence: Early Eocene (Ypresian) to Middle Eocene (?early Lutetian).
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Williams et al., 2015]:
Diagnosis:
Wetzelielloidean cysts with a latiepeliform archeopyle and pericyst with processes distally united by membranes (ectophragm).
Description:
Shape: Dorso-ventral outline of pericyst rhomboidal, horns weakly to moderately well developed.
Dorso-ventral outline of endocyst rounded to rhomboidal.
Wall structure: Periphragm moderately thick, ornamented with processes that tend to show alignment to sutures or may be marginally distributed; processes distally connected by membranes. Endophragm thin, smooth.
Pericoels: Cysts circumcavate to cornucavate.
Tabulation: Weakly to moderately delineated by the processes and possibly by ectophragmal membranes.
Archeopyle: Latiepeliform, with no or minimal extension into apical pericoel, operculum free. Endoarcheopyle of same size or smaller than periarcheopyle, operculum free.
Cingulum: may be expressed by single row of processes; sulcus devoid of processes.
Size: Intermediate to large.
Affinities/Discussion:
Other genera with latiepeliform archeopyles are Dracodinium, Petalodinium, Stichodinium and Kledodinium. The periphragm of Dracodinium has processes that are more or less uniform in distribution and distally free. Stichodinium also has distally free processes, but having a sutural or penitabular distribution. Petalodinium has a periphragm that is smooth or ornamented with features of low relief and more or less uniform distribution. Kledodinium has processes distally linked by trabeculae rather than membranes. Other wetzelielloidean genera with processes distally connected by membranes are Charlesdowniea and Talladinium, but these have equiepeliform and soleiform archeopyles, respectively. The holotype of Piladinium columna has a pericyst 121 μm long and 124 μm wide. The holotype of Piladinium edwardsii has a pericyst 96 μm long and 107 μm wide and an endocyst 50 μm long and 58 μm wide.