Back
Soaniella guttiformis
From Fensome et al., 2019:
---------------------------------------------------------------------------------------------------
ORiginal description Vasilyeva, 2012:
The name comes from guttiformis (lat.) – drop-shaped.
Diagnosis. A medium-sized pericyst with cornucopia. The pericyst is round-oval, drop-shaped. The epicyst has a short apical horn in the form of a papilla. Antapical horns are absent. The periphragm is thin, granular. The endocyst is round-oval. The endophragm is thin. The paracingulum is flat, marked by a double suture of the slightly protruding periphragm on the dorsal and ventral sides of the cyst. The periarchaeopile is combined, type A3I3P (3' + 1a-3a + 3"-5"). The operculum – the middle dorsal intercalary plate (2a) – is free.
Diagnosis. Cornucavate peridiniaceans cysts of in-termediate size. Pericyst is rounded, Epicyst has short apical nipple-like horn. Antapical horns are absent. Periphragm is thin, and endocyst is rounded. Endophragm is thin.
Description. The pericyst is round-oval. The epicyst and hypocyst are equal. The epicyst has a small apical horn in the form of a papilla. The hypocyst is semicircular, without antapical horns. The absence of antapical horns and the papillary apical horn give the cyst a drop-shaped form. The periphragm is thin, granular. The contour of the cyst is distinct and smooth. The endocyst is oval, adjacent to the pericyst. A small pericoel is observed only in the area of the apical horn. The cyst is cornucopia. The endophragma is thin. The paracingulum is usually very weakly expressed, marked by a thin double suture on the dorsal and ventral surfaces of the cyst. The sulcus is limited by ridges on the ventral side of the cyst. Periarchaeopile combined, type A3I3P(3'+1a-3a+3"-5"). Operculum – middle intercalary plate – free. Paratabulation is expressed by the structure of archaeopile, cingulum and sulcus.
Holotype. Plate 1, Fig. 13, 14. Ref. K14/130–25A.
Location. Well K-14 (Komsomolskaya), Komsomolsky settlement, Khanty-Mansiysk Autonomous Okrug, Russia.
Dimensions (μm). Holotype: pericyst length – 66, pericyst width – 63. Other specimens (6 specimens): pericyst length – 62–69, pericyst width – 53–66.
Comparison. Soaniella guttiformis sp. ov. differs from other species of this genus by the absence of antapical horns, the characteristic teardrop shape of the cyst, and the comparatively thin periphragm.
Distribution. Russia, Western Siberia, upper reaches of the Konda River, Nyurol Formation. Eocene (Ypresian-Lutetian).
Notes: Cysts of Soaniella guttiformis sp. nov. often appear heavily destroyed. It is possible that postcingulate plates are additionally involved in the formation of the archeopyle. However, due to the relatively small sample, it is impossible to say whether such “cracked” forms are typical for the species or are the result of poor preservation of the material.
---------------------------------------------------------------------------------------------------
ORiginal description Vasilyeva, 2012:
The name comes from guttiformis (lat.) – drop-shaped.
Diagnosis. A medium-sized pericyst with cornucopia. The pericyst is round-oval, drop-shaped. The epicyst has a short apical horn in the form of a papilla. Antapical horns are absent. The periphragm is thin, granular. The endocyst is round-oval. The endophragm is thin. The paracingulum is flat, marked by a double suture of the slightly protruding periphragm on the dorsal and ventral sides of the cyst. The periarchaeopile is combined, type A3I3P (3' + 1a-3a + 3"-5"). The operculum – the middle dorsal intercalary plate (2a) – is free.
Diagnosis. Cornucavate peridiniaceans cysts of in-termediate size. Pericyst is rounded, Epicyst has short apical nipple-like horn. Antapical horns are absent. Periphragm is thin, and endocyst is rounded. Endophragm is thin.
Description. The pericyst is round-oval. The epicyst and hypocyst are equal. The epicyst has a small apical horn in the form of a papilla. The hypocyst is semicircular, without antapical horns. The absence of antapical horns and the papillary apical horn give the cyst a drop-shaped form. The periphragm is thin, granular. The contour of the cyst is distinct and smooth. The endocyst is oval, adjacent to the pericyst. A small pericoel is observed only in the area of the apical horn. The cyst is cornucopia. The endophragma is thin. The paracingulum is usually very weakly expressed, marked by a thin double suture on the dorsal and ventral surfaces of the cyst. The sulcus is limited by ridges on the ventral side of the cyst. Periarchaeopile combined, type A3I3P(3'+1a-3a+3"-5"). Operculum – middle intercalary plate – free. Paratabulation is expressed by the structure of archaeopile, cingulum and sulcus.
Holotype. Plate 1, Fig. 13, 14. Ref. K14/130–25A.
Location. Well K-14 (Komsomolskaya), Komsomolsky settlement, Khanty-Mansiysk Autonomous Okrug, Russia.
Dimensions (μm). Holotype: pericyst length – 66, pericyst width – 63. Other specimens (6 specimens): pericyst length – 62–69, pericyst width – 53–66.
Comparison. Soaniella guttiformis sp. ov. differs from other species of this genus by the absence of antapical horns, the characteristic teardrop shape of the cyst, and the comparatively thin periphragm.
Distribution. Russia, Western Siberia, upper reaches of the Konda River, Nyurol Formation. Eocene (Ypresian-Lutetian).
Notes: Cysts of Soaniella guttiformis sp. nov. often appear heavily destroyed. It is possible that postcingulate plates are additionally involved in the formation of the archeopyle. However, due to the relatively small sample, it is impossible to say whether such “cracked” forms are typical for the species or are the result of poor preservation of the material.