Back
Senegalinium microgranulatum
Senegalinium microgranulatum (Stanley, 1965) Stover and Evitt, 1978
Originally Deflandrea, subsequently Alterbia (combination illegitimate), thirdly (and now) Senegalinium.
Holotype: Stanley, 1965, pl.19, figs.4-5
Locus typicus: South Dakota, USA
Stratum typicum: Paleocene
------------------------------------------------
Original description: Stanley, 1965, p.219: Deflandrea microgranulata
Outer cyst subcircular in dorso-ventral view; length 54-57 µm. width 45-48 µm; outer cyst wall smooth and thin. Apical horn conically shaped, length about 7 µm; apical horn appears to bear a pore at its distal end. Antapical horns unequal in length with left one being short (about 5 µm in length), whereas the right one is only slightly developed. Inner cyst completely fills outer cyst, pentagonally shaped with the postelior end flattened; small granulations with a diameter of about 0.3 µm ornament the membrane of the inner cyst. Girdle characterized by a wide band that is well developed on the dorsal side and blends into the furrow on the ventral side. Archeopyle often distinct with the anterior and posterior sides being about equal in length.
Affinities:
Stanley, 1965, p.219: Deflandrea microgranulata
Deflandrea microgranulata, closely resembles D. ventriosa Alberti, 1959. The only difference that could be determined from Alberti"s description and illustration is that D. microgranulata has a slightly smaller size and the apical horn bears a distal pore.
------------------------------------------------------------
Description: Kurita and McIntyre 1995, p. 132
Cysts compressed peridinioid. Ambital outline spherical to subspherical. Epicyst and hypocyst
equal in size. Endocyst spherical to subspherical, its length equal to or slightly greater than width. One short apical horn present. Antapical horns short, usually unequally developed with right antapical horn reduced or absent, or occasionally equally developed. Cysts cornucavate. Endophragm and periphragm appressed except in horns, where small pericoels are present. Periphragm smooth, or with faint, longitudinal wrinkles. Endophragm always finely to coarsely granulate. Paratabulation indicated only by archeopyle, paracingulum and accessory sutures. Archeopyle isodeltaform hexa 2a intercalary, average transverse archeopyle index 0.5. Operculum two layered, generally attached at posterior margin, rarely free. Accessory sutures along 1 a/3 ",3 "14",4"/5 " and 3a/5 " paraplate sutures commonly discernible. Paracingulum usually faintly expressed by two, low equatorial folds. Parasulcus indicated by absence of paracingular folds.
Dimensions:
Overall length 53 - 71 µm (average 63,um); overall width 42 - 61 µm (average 50 µm); apical horn length 3 -9 µm (average 6 µm); left antapical horn length 3 - 9 µm (average 7 µm); 20 specimens measured. Transverse archeopyle index 0.4 -0.6 (average 0.5); 8 specimens measured.
Remarks. Kurita and McIntyre 1995, p. 132
The species is characterized by a relatively large archeopyle with frequent development of accessory sutures, and by a granulate endophragm. It is similar to Senegalinium? asymmetricum (Wilson 1967) Stover & Evitt 1978 in having unequally developed antapical horns, but differs from the latter in lacking both a prominent apical horn and longitudinal, keel-like ridges on the epipericyst. The generic assignment of S. microgranulatum, as in S.? asymmetricum, is slightly inconsistent with the emended generic diagnosis of Stover and Evitt (1978), because of the frequent unequal development of the antapical horns.
Occurrence. S. microgranulatum was recorded rarely to commonly from the Peace Garden Member of the Turtle Mountain Formation. The species is common to abundant in the Cannonball Formation at Huff.
----------------------------------------------------
Originally Deflandrea, subsequently Alterbia (combination illegitimate), thirdly (and now) Senegalinium.
Holotype: Stanley, 1965, pl.19, figs.4-5
Locus typicus: South Dakota, USA
Stratum typicum: Paleocene
------------------------------------------------
Original description: Stanley, 1965, p.219: Deflandrea microgranulata
Outer cyst subcircular in dorso-ventral view; length 54-57 µm. width 45-48 µm; outer cyst wall smooth and thin. Apical horn conically shaped, length about 7 µm; apical horn appears to bear a pore at its distal end. Antapical horns unequal in length with left one being short (about 5 µm in length), whereas the right one is only slightly developed. Inner cyst completely fills outer cyst, pentagonally shaped with the postelior end flattened; small granulations with a diameter of about 0.3 µm ornament the membrane of the inner cyst. Girdle characterized by a wide band that is well developed on the dorsal side and blends into the furrow on the ventral side. Archeopyle often distinct with the anterior and posterior sides being about equal in length.
Affinities:
Stanley, 1965, p.219: Deflandrea microgranulata
Deflandrea microgranulata, closely resembles D. ventriosa Alberti, 1959. The only difference that could be determined from Alberti"s description and illustration is that D. microgranulata has a slightly smaller size and the apical horn bears a distal pore.
------------------------------------------------------------
Description: Kurita and McIntyre 1995, p. 132
Cysts compressed peridinioid. Ambital outline spherical to subspherical. Epicyst and hypocyst
equal in size. Endocyst spherical to subspherical, its length equal to or slightly greater than width. One short apical horn present. Antapical horns short, usually unequally developed with right antapical horn reduced or absent, or occasionally equally developed. Cysts cornucavate. Endophragm and periphragm appressed except in horns, where small pericoels are present. Periphragm smooth, or with faint, longitudinal wrinkles. Endophragm always finely to coarsely granulate. Paratabulation indicated only by archeopyle, paracingulum and accessory sutures. Archeopyle isodeltaform hexa 2a intercalary, average transverse archeopyle index 0.5. Operculum two layered, generally attached at posterior margin, rarely free. Accessory sutures along 1 a/3 ",3 "14",4"/5 " and 3a/5 " paraplate sutures commonly discernible. Paracingulum usually faintly expressed by two, low equatorial folds. Parasulcus indicated by absence of paracingular folds.
Dimensions:
Overall length 53 - 71 µm (average 63,um); overall width 42 - 61 µm (average 50 µm); apical horn length 3 -9 µm (average 6 µm); left antapical horn length 3 - 9 µm (average 7 µm); 20 specimens measured. Transverse archeopyle index 0.4 -0.6 (average 0.5); 8 specimens measured.
Remarks. Kurita and McIntyre 1995, p. 132
The species is characterized by a relatively large archeopyle with frequent development of accessory sutures, and by a granulate endophragm. It is similar to Senegalinium? asymmetricum (Wilson 1967) Stover & Evitt 1978 in having unequally developed antapical horns, but differs from the latter in lacking both a prominent apical horn and longitudinal, keel-like ridges on the epipericyst. The generic assignment of S. microgranulatum, as in S.? asymmetricum, is slightly inconsistent with the emended generic diagnosis of Stover and Evitt (1978), because of the frequent unequal development of the antapical horns.
Occurrence. S. microgranulatum was recorded rarely to commonly from the Peace Garden Member of the Turtle Mountain Formation. The species is common to abundant in the Cannonball Formation at Huff.
----------------------------------------------------