Back
Leberidocysta spinosa
From Fensome et al., 2019:
Leberidocysta spinosa Pestchevitskaya, 2009, p.110–111, pl.1, figs.5,7–9, text-fig.2C. Holotype: Pestchevitskaya, 2009, pl.1, fig,5. Age: Berriasian–early Valanginian.
---------------------------------------------------------------------------------------------------
Original description: [Pestchevitskaya, 2009] (translated from Russian):
Leberidocysta spinosa Pestchevitskaya sp. n.
Plate, figs. 5, 7–9; fig. 2, B
1995 Insertae sedis 2: Heilmann-Clausen et Thomas, p. 310, pl. 4, fi gs. 4–6
Origin of the name. From Latin spina (thorn), after the sculpture of the pericyst.
Holotype. Specimen No. 842/125.1-13 CSGM, pl. I, fig. 5; Nordvik Peninsula, outcrop 33, sample 43.1, prep. 125.1, Berriasian, Tollia tolli Zone.
Paratype. Specimen No. 842/125.1-5 CSGM, pl. I, fig. 8, Nordvik Peninsula, exp. 33, sample 43.1, 125.1, Berrias, Tollia tolli zone.
Diagnosis. Cyst proximate circumcavate; endocyst and pericyst from spherical to ellipsoidal (long axis has lateral position), endophragm rather thick sculptured by spines and granules; periphragm rather thin, transparent, sculptured by spines and granules; paratabulation may be expressed by parasutural features on the endocyst and fi ner on the pericyst; formula: 4’, 3a, 6’’, 6c, 5s, 6’’’, 1p, 1’’’’, archeopyle composed combination, type tAtI.
Material. 15 specimens in good and satisfactory preservation.
Description. The cyst is proximal, circumcised, the pericoel is usually uniformly developed, sometimes expanding in the antapical region. The endocyst is spherical or ellipsoid, in the latter case the long axis is located in the lateral direction. The endophragm is fairly dense, yellow in color, sculptured with medium-sized granules and columnar spines (0.3–0.8 μm) with flat tops. The granules are located fairly densely, the spines are much rarer and unevenly distributed. Sometimes only a few individual rare spines are observed. The pericyst is spherical, with a fairly thin transparent periphragm, which is often crumpled into various folds. The periphragm is sculptured in the same way as the endophragm, but the granules are smaller and more frequent, and the spines are somewhat longer (0.5–1.2 µm) and usually evenly spaced. Paratabulation is not always clearly visible, especially on the pericyst, where it is often poorly visible. It is expressed by parasutural lines, formula: 4’, 3a, 6’’, 6c, 5s, 6’’’, 1p, 1’’’’. The straight paracingulum and parasulcus are marked by parasutural lines, sometimes by folds of the periphragm. The archaeopile is compound, of the combined type (tAtI).
Dimensions (µm). Pericyst length is 40–54, endocyst length is 26–32, pericyst width is 30–52, endocyst width is 30–45, pericyst width in the cingular region is 4–6, in the antapical region is 4–9.
Variability. The sculpture of the periphragm and endophragm varies considerably: on many specimens, the spines are located relatively densely, while on others, only a few individual spines are present. This may be due to preservation. Variability is also observed in the pericyst width and the shape of the endocyst, which can be spherical or ellipsoid.
Comparison. The closest species is L. defl occata (Davey et Verdier) Stover et Evitt [Burger, 1980], which is similar in the shape of the endo- and pericyst, as well as the structure of the pericoel, but differs in a smooth, thinner periphragm and the absence of a clear paratabulation, which is expressed only by the archeopyle. The new species differs from the species L. ?pergamentacea (Burger) Burger [Ibid.] in a denser sculptured periphragm, which is crumpled into coarser folds, and a fairly clearly expressed paratabulation. The species L. chlamydata [Cookson,
Eisenack, 1962] has an oval endocyst (the long axis is located axially), as well as a smooth or pitted periphragm.
Location. Nordvik Peninsula, outcrop 33, layers 31–64, Berriasian–lower Valanginian, Surites analogus – Neotollia klimovskiensis zones; outcrop 35, layers 34–35, lower Valanginian, Euryptychites astieryptichys zone; outcrop 36, layer 11, lower Hauterivian, Homolsomites bojarkensis zone.
Leberidocysta spinosa Pestchevitskaya, 2009, p.110–111, pl.1, figs.5,7–9, text-fig.2C. Holotype: Pestchevitskaya, 2009, pl.1, fig,5. Age: Berriasian–early Valanginian.
---------------------------------------------------------------------------------------------------
Original description: [Pestchevitskaya, 2009] (translated from Russian):
Leberidocysta spinosa Pestchevitskaya sp. n.
Plate, figs. 5, 7–9; fig. 2, B
1995 Insertae sedis 2: Heilmann-Clausen et Thomas, p. 310, pl. 4, fi gs. 4–6
Origin of the name. From Latin spina (thorn), after the sculpture of the pericyst.
Holotype. Specimen No. 842/125.1-13 CSGM, pl. I, fig. 5; Nordvik Peninsula, outcrop 33, sample 43.1, prep. 125.1, Berriasian, Tollia tolli Zone.
Paratype. Specimen No. 842/125.1-5 CSGM, pl. I, fig. 8, Nordvik Peninsula, exp. 33, sample 43.1, 125.1, Berrias, Tollia tolli zone.
Diagnosis. Cyst proximate circumcavate; endocyst and pericyst from spherical to ellipsoidal (long axis has lateral position), endophragm rather thick sculptured by spines and granules; periphragm rather thin, transparent, sculptured by spines and granules; paratabulation may be expressed by parasutural features on the endocyst and fi ner on the pericyst; formula: 4’, 3a, 6’’, 6c, 5s, 6’’’, 1p, 1’’’’, archeopyle composed combination, type tAtI.
Material. 15 specimens in good and satisfactory preservation.
Description. The cyst is proximal, circumcised, the pericoel is usually uniformly developed, sometimes expanding in the antapical region. The endocyst is spherical or ellipsoid, in the latter case the long axis is located in the lateral direction. The endophragm is fairly dense, yellow in color, sculptured with medium-sized granules and columnar spines (0.3–0.8 μm) with flat tops. The granules are located fairly densely, the spines are much rarer and unevenly distributed. Sometimes only a few individual rare spines are observed. The pericyst is spherical, with a fairly thin transparent periphragm, which is often crumpled into various folds. The periphragm is sculptured in the same way as the endophragm, but the granules are smaller and more frequent, and the spines are somewhat longer (0.5–1.2 µm) and usually evenly spaced. Paratabulation is not always clearly visible, especially on the pericyst, where it is often poorly visible. It is expressed by parasutural lines, formula: 4’, 3a, 6’’, 6c, 5s, 6’’’, 1p, 1’’’’. The straight paracingulum and parasulcus are marked by parasutural lines, sometimes by folds of the periphragm. The archaeopile is compound, of the combined type (tAtI).
Dimensions (µm). Pericyst length is 40–54, endocyst length is 26–32, pericyst width is 30–52, endocyst width is 30–45, pericyst width in the cingular region is 4–6, in the antapical region is 4–9.
Variability. The sculpture of the periphragm and endophragm varies considerably: on many specimens, the spines are located relatively densely, while on others, only a few individual spines are present. This may be due to preservation. Variability is also observed in the pericyst width and the shape of the endocyst, which can be spherical or ellipsoid.
Comparison. The closest species is L. defl occata (Davey et Verdier) Stover et Evitt [Burger, 1980], which is similar in the shape of the endo- and pericyst, as well as the structure of the pericoel, but differs in a smooth, thinner periphragm and the absence of a clear paratabulation, which is expressed only by the archeopyle. The new species differs from the species L. ?pergamentacea (Burger) Burger [Ibid.] in a denser sculptured periphragm, which is crumpled into coarser folds, and a fairly clearly expressed paratabulation. The species L. chlamydata [Cookson,
Eisenack, 1962] has an oval endocyst (the long axis is located axially), as well as a smooth or pitted periphragm.
Location. Nordvik Peninsula, outcrop 33, layers 31–64, Berriasian–lower Valanginian, Surites analogus – Neotollia klimovskiensis zones; outcrop 35, layers 34–35, lower Valanginian, Euryptychites astieryptichys zone; outcrop 36, layer 11, lower Hauterivian, Homolsomites bojarkensis zone.