Back
Impagidinium manumii
Impagidinium manumii Matsuoka and Bujak, 1988
Holotype: Matsuoka and Bujak, 1988, pl.6,fig.5a-b, text-fig.10
Paratype: Matsuoka and Bujak, 1988
Locus typicus: Norton Sound COST No. 1 Well, Bering Sea
Stratum typicum: Hystrichophaeropsis uariabile Zone; Late Miocene
Original diagnosis: Matsuoka and Bujak, 1988, p.54
Intermediate proximate cyst with an ovoidal to ellipsoidal shape. Epicyst broadly triangular in dorso-ventral view, approximately equal to the hypocyst in size, and without an apical projection; hypocyst hemispherical without antapical horns. Cyst wall composed of a thick spongy periphragm and a thin smooth endophragm, adpressed except at the parasutural septa. Septa roughly undulate, somewhat membranous, low and granular, and clearly representing the paratabulation, 4", 6", 6c, 6""", 1p, 1"""", xs. The 4" paraplate is rectangular, similar to paraplate 1" in shape and size; paraplate 6" narrowly triangular; paraplate 1""" small, usually strongly reduced and narrowly rectangular. Paracingulum distinct and displaced laevorotary; parasulucus delimited by parasutural septa, and straight to slightly sigmoidal. Archeopyle precingular, formed by the loss of paraplate 3".
Original description: Matsuoka and Bujak, 1988, p.55
The central body is generally longer than broad, although specimens with a spherical endocyst rarely occur. The periphragm is spongy, 1.5 to 2Ám thick and forms parasutural septa which are undulate and well-developed over the entire cyst. Paraplate 6" is typically triangular and has parasutural crests that are lower in height than the other precingular paraplates. The 1""" paraplate is much reduced. The paracingulum is well-defined by parasutural septa and almost complete, laevoratary and displaced by half its own width. The parasulcus extends onto the epicyst, widens toward the antapex, and comprises paraplates as, ps, ls, rs. The archeopyle is trapezoidal, precingular and formed by the loss of paraplate 3.
Dimensions: Holotype; length of central body 54 µm, width 54 µm, height of parasutural septa ca, 4 µm, thickness of cyst wall ca, 2 µm. Range; length of cyst 54-56 µm, width 48-54 µm, height of parasutrral septa 5-6 µm. Number of specimens measured; 5.
Matsuoka and Bujak, 1988, p.55: Impagidinium manumii resembles I. sphaericum (Wall), but differs in having a thicker spongy periphragm and in lacking an apical boss. I. manumii is also similar to I. multiplexum (Wall and Dale) in possessing a granular periphragm, but differs in having lower parasutural septa (about one-third of the cyst diameter) and well-developed paracingular plates. I,eptodinium sp. IV of Manum (1976, pl. 1, fig. 18) and Impagidinium sp. of Wiggins (1986, pl. 2, fig. 1-2) may be conspecific with Impaginium manumii.
Wiggins (1986) noted that Impagidinium sp. has five precingular paraplates, because the paraplate which is equivalent to the 6" paraplate in Kofoidian terms appears to be missing. Based on observation of this species in the Bering Sea, the 6" paraplate is variable in shape, is sometimes not strongly reduced, and therefore the presence of this paraplate can be recognized from the topological relations in the parasulcus, paracingulum, the 5"" and 4" paraplate.
Holotype: Matsuoka and Bujak, 1988, pl.6,fig.5a-b, text-fig.10
Paratype: Matsuoka and Bujak, 1988
Locus typicus: Norton Sound COST No. 1 Well, Bering Sea
Stratum typicum: Hystrichophaeropsis uariabile Zone; Late Miocene
Original diagnosis: Matsuoka and Bujak, 1988, p.54
Intermediate proximate cyst with an ovoidal to ellipsoidal shape. Epicyst broadly triangular in dorso-ventral view, approximately equal to the hypocyst in size, and without an apical projection; hypocyst hemispherical without antapical horns. Cyst wall composed of a thick spongy periphragm and a thin smooth endophragm, adpressed except at the parasutural septa. Septa roughly undulate, somewhat membranous, low and granular, and clearly representing the paratabulation, 4", 6", 6c, 6""", 1p, 1"""", xs. The 4" paraplate is rectangular, similar to paraplate 1" in shape and size; paraplate 6" narrowly triangular; paraplate 1""" small, usually strongly reduced and narrowly rectangular. Paracingulum distinct and displaced laevorotary; parasulucus delimited by parasutural septa, and straight to slightly sigmoidal. Archeopyle precingular, formed by the loss of paraplate 3".
Original description: Matsuoka and Bujak, 1988, p.55
The central body is generally longer than broad, although specimens with a spherical endocyst rarely occur. The periphragm is spongy, 1.5 to 2Ám thick and forms parasutural septa which are undulate and well-developed over the entire cyst. Paraplate 6" is typically triangular and has parasutural crests that are lower in height than the other precingular paraplates. The 1""" paraplate is much reduced. The paracingulum is well-defined by parasutural septa and almost complete, laevoratary and displaced by half its own width. The parasulcus extends onto the epicyst, widens toward the antapex, and comprises paraplates as, ps, ls, rs. The archeopyle is trapezoidal, precingular and formed by the loss of paraplate 3.
Dimensions: Holotype; length of central body 54 µm, width 54 µm, height of parasutural septa ca, 4 µm, thickness of cyst wall ca, 2 µm. Range; length of cyst 54-56 µm, width 48-54 µm, height of parasutrral septa 5-6 µm. Number of specimens measured; 5.
Matsuoka and Bujak, 1988, p.55: Impagidinium manumii resembles I. sphaericum (Wall), but differs in having a thicker spongy periphragm and in lacking an apical boss. I. manumii is also similar to I. multiplexum (Wall and Dale) in possessing a granular periphragm, but differs in having lower parasutural septa (about one-third of the cyst diameter) and well-developed paracingular plates. I,eptodinium sp. IV of Manum (1976, pl. 1, fig. 18) and Impagidinium sp. of Wiggins (1986, pl. 2, fig. 1-2) may be conspecific with Impaginium manumii.
Wiggins (1986) noted that Impagidinium sp. has five precingular paraplates, because the paraplate which is equivalent to the 6" paraplate in Kofoidian terms appears to be missing. Based on observation of this species in the Bering Sea, the 6" paraplate is variable in shape, is sometimes not strongly reduced, and therefore the presence of this paraplate can be recognized from the topological relations in the parasulcus, paracingulum, the 5"" and 4" paraplate.