Back
Impagidinium eugubinum
Impagidinium eugubinum Biffi and Manum, 1988
Holotype: Biffi and Manum, 1988, pl. 12, fig. 18
Locus typicus: Schlier Fm., Ca" Tosi section, Marche region, Italy
Stratum typicum: Early Miocene
Original description: Biffi and Manum, 1988, p. 206
Diagnosis: A species of Impagidinium characterized by an ornamentation of closely spaced dome-shaped to nipple-like prominences up to 2 µm high and approximately 2 µm across.
Dimensions: Holotype: cyst length 72 µm, breadth 54 µm. Mean values (bracketed) and extremes (n = 8): cyst length 50(66)72 µm, breadth 42(52)60 µm.
Description (annotated): Promimate cyst of ovoidal shape, epicyst and hypocyst approximately equal. Cyst wall composed of an unstructured inner layer c. 0.5 µ thick and an outer, slightly thicker spongy layer with dome-shaped to nipple-like prominences up to 2 µ high and approximately 2 µ across. Almost hyaline parasutural crests, 2-3 µ high, show the paratabulation 4", 6"", 6c, 5""", 1p, 1"""", ps. Archeopyle formed by loss of paraplate 3"". The crests are formed by closely appressed twin layers as can be seen from the median line separating the two layers at the crest base when the wall is observed in surface view. Unlike the outer wall layer, the crests are not spongy. Paraplate 6"" is subtriangular with a very brief contact with 4". Paraplates 1" and 4" are of nearly same size and shape, being narrow and elongate.
Affinities:
Biffi and Manum, 1988, p. 206
Impagidinium eugubinum is easily recognized by its surface features, which differentiate it from all previously described species of the genus.
Holotype: Biffi and Manum, 1988, pl. 12, fig. 18
Locus typicus: Schlier Fm., Ca" Tosi section, Marche region, Italy
Stratum typicum: Early Miocene
Original description: Biffi and Manum, 1988, p. 206
Diagnosis: A species of Impagidinium characterized by an ornamentation of closely spaced dome-shaped to nipple-like prominences up to 2 µm high and approximately 2 µm across.
Dimensions: Holotype: cyst length 72 µm, breadth 54 µm. Mean values (bracketed) and extremes (n = 8): cyst length 50(66)72 µm, breadth 42(52)60 µm.
Description (annotated): Promimate cyst of ovoidal shape, epicyst and hypocyst approximately equal. Cyst wall composed of an unstructured inner layer c. 0.5 µ thick and an outer, slightly thicker spongy layer with dome-shaped to nipple-like prominences up to 2 µ high and approximately 2 µ across. Almost hyaline parasutural crests, 2-3 µ high, show the paratabulation 4", 6"", 6c, 5""", 1p, 1"""", ps. Archeopyle formed by loss of paraplate 3"". The crests are formed by closely appressed twin layers as can be seen from the median line separating the two layers at the crest base when the wall is observed in surface view. Unlike the outer wall layer, the crests are not spongy. Paraplate 6"" is subtriangular with a very brief contact with 4". Paraplates 1" and 4" are of nearly same size and shape, being narrow and elongate.
Affinities:
Biffi and Manum, 1988, p. 206
Impagidinium eugubinum is easily recognized by its surface features, which differentiate it from all previously described species of the genus.