Back
Oligosphaeridium heilongjiangense
Oligosphaeridium heilongiiangense Yu Jingxian, 1982
Holotype: Yu Jingxian, 1982, pl.5, fig.4
Age: Valanginian-Hauterivian
Description: Cysts circular to elliptical in outline. Periphragm and endophragm. Endophragm thicker than periphragm. Surface granulate or reticulate. Complete specimens have 18 processes. Processes of two types. One type is tubular, hollow, dilated at ends to appear like inverted funnel and split on sides to form fine spines. This type of process is 26 - 34 µm long, 6 -10 µm wide at base and 22 - 24 µm wide at ends. The other type of process is finely branched, 3 - 4 µm wide at base, expanding at ends to 12 - 22 µm and splitting to appear digitate. Paratabulation is 4", 5-6"", 6""", 1p, 1""". Apical archeopyle, formed by loss of apical processes 1- 4".
Size: Cysts 50 - 56 µm in diameter not including processes).
Comparison: The new species has some resemblance to O. albertense in its cyst outline and two types of processes but is distinguished from the latter by the fact that its endophragm is thicker than its periphragm and the large processes split into small spines at the ends while the small processes are branched, with deep splits at the ends that create a digitate appearance.
Holotype: Yu Jingxian, 1982, pl.5, fig.4
Age: Valanginian-Hauterivian
Description: Cysts circular to elliptical in outline. Periphragm and endophragm. Endophragm thicker than periphragm. Surface granulate or reticulate. Complete specimens have 18 processes. Processes of two types. One type is tubular, hollow, dilated at ends to appear like inverted funnel and split on sides to form fine spines. This type of process is 26 - 34 µm long, 6 -10 µm wide at base and 22 - 24 µm wide at ends. The other type of process is finely branched, 3 - 4 µm wide at base, expanding at ends to 12 - 22 µm and splitting to appear digitate. Paratabulation is 4", 5-6"", 6""", 1p, 1""". Apical archeopyle, formed by loss of apical processes 1- 4".
Size: Cysts 50 - 56 µm in diameter not including processes).
Comparison: The new species has some resemblance to O. albertense in its cyst outline and two types of processes but is distinguished from the latter by the fact that its endophragm is thicker than its periphragm and the large processes split into small spines at the ends while the small processes are branched, with deep splits at the ends that create a digitate appearance.