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Batiacasphaera compta
Batiacasphaera compta, Drugg, 1970
Holotype: Drugg, 1970, fig.6A-B
Locus typicus: Jackson, on west side of U. S. Highway 43, Little Stave Creek, Clarke County, Alabama, USA
Stratum typicum: Late Eocene
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Original description: [Drugg, 1970, p. 813-814]:
Description:
Tract spherical with an apical archeopyle. The operculum is several sided in outline (see Fig. 6 C) and probably represents four plates. Rarely there is a weakly developed central thickening on the operculum. The operculum detaches leaving a characteristic zigzag line of separation suggesting the presence of six precingular plates and a sulcus. Crushed specimens often exhibit splits extending downward from the archeopyle which suggest rudimentary plate formation (see Fig. 7 A).
Very rarely a narrow indistinct cingulum is suggested.
The wall is thin and is distinctively ornamented with a fine reticulum composed of low (about 2 µm) small rod-shaped elements (see Fig. 7 B). The muri are usually formed by one to three rows of rods. The lumens are polygonal to rounded and average 1-2 µm in diameter. A few specimens do not exhibit much of a reticulum but instead have the rod-shaped elements arranged without any noticeable organization. At the other end of the spectrum, a few specimens have low, broad, seemingly solid, muri which give the tract a foveolate appearance. Perhaps these end forms could be considered as separate species but at present I consider them as variants of Batiacasphaera compta. The tract diameter ranges from 49-80 µm, most being about 65 µm.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Batiacasphaera compta Drugg, 1970b, has a thin wall, which is distinctively ornamented with a fine reticulum composed of low (about 2 µm), small, rod-shaped elements. The lumina are polygonal to rounded and average 1 to 2 µm in diameter. Some specimens have the rod-shaped elements arranged in no particular pattern. Some extreme forms have low, broad, seemingly solid muri, which give the test a foveolate appearance.
Size: 49-80 µm.
Holotype: Drugg, 1970, fig.6A-B
Locus typicus: Jackson, on west side of U. S. Highway 43, Little Stave Creek, Clarke County, Alabama, USA
Stratum typicum: Late Eocene
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Drugg, 1970, p. 813-814]:
Description:
Tract spherical with an apical archeopyle. The operculum is several sided in outline (see Fig. 6 C) and probably represents four plates. Rarely there is a weakly developed central thickening on the operculum. The operculum detaches leaving a characteristic zigzag line of separation suggesting the presence of six precingular plates and a sulcus. Crushed specimens often exhibit splits extending downward from the archeopyle which suggest rudimentary plate formation (see Fig. 7 A).
Very rarely a narrow indistinct cingulum is suggested.
The wall is thin and is distinctively ornamented with a fine reticulum composed of low (about 2 µm) small rod-shaped elements (see Fig. 7 B). The muri are usually formed by one to three rows of rods. The lumens are polygonal to rounded and average 1-2 µm in diameter. A few specimens do not exhibit much of a reticulum but instead have the rod-shaped elements arranged without any noticeable organization. At the other end of the spectrum, a few specimens have low, broad, seemingly solid, muri which give the tract a foveolate appearance. Perhaps these end forms could be considered as separate species but at present I consider them as variants of Batiacasphaera compta. The tract diameter ranges from 49-80 µm, most being about 65 µm.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Batiacasphaera compta Drugg, 1970b, has a thin wall, which is distinctively ornamented with a fine reticulum composed of low (about 2 µm), small, rod-shaped elements. The lumina are polygonal to rounded and average 1 to 2 µm in diameter. Some specimens have the rod-shaped elements arranged in no particular pattern. Some extreme forms have low, broad, seemingly solid muri, which give the test a foveolate appearance.
Size: 49-80 µm.