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Impletosphaeridium lorum
Impletosphaeridium lorum Wrenn and Hart, 1988, p.357, fig.26, nos.1-2.
Holotype: Wrenn and Hart, 1988, fig.26, nos.1-2. N.I.A.
Age: Paleocene-Eocene.
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Impletosphaeridium lorum sp.
Figure 26.1-2
Diagnosis. A species of Impletosphaeridium characterized by acuminate, whip-like solid, but highly flexible, processes.
Description.
Shape: The central body is subspherical to ellipsoidal.
Phragma: The central body is less than 1 μm thick and is composed of an autophragm or closely appressed periphragm and endophragm. The surface texture of the central body is shagreenate to granular. The 50 to 100 nontabular processes are solid, whip-like, and distally acuminate. The processes appear to be highly flexible.
Paratabulation: None evident.
Paracingulum: None evident.
Parasulcus: None evident.
Archeopyle: None evident.
Dimensions. Observed range (four specimens): length, 21 to 33 (mean, 27 μm); width, 21 to 25 μm (mean, 22 μm): processes, 10 to 15
μm; autophragm, less than 1 μm thick.
Discussion and Comparison with Other Species. Although I. lorum sp. nov. superficially resembles I. ligospinosum (De Coninck) Islam, 1983, the former is characterized by whip-like acuminate processes. The processes of I. ligospinosum, on the other hand, are quite stiff, and their
terminations are bifid or capitate. I. lorum sp. nov. has fewer, longer processes (as much as 15 μm long) than Micrhystridium sp. A. The latter
has a dense covering of processes less than 8 μm long.
Holotype. Slide 8496, W/8, 114.2 x 20.7 (W19). Sample 8496, Section 16, Cross Valley Formation, early late Paleocene, Seymous Island, Antarctica.
Derivation of Name. Latin, lorum, whip or scourge, with reference to the whip-like processes.
Stratigraphic Occurrence. Cross Valley Formation (Section 12-13, Paleocene; Sections 15 and 16, early late Paleocene); La Meseta Formation
(Section 3, Eocene; Sections 17, 18, and 19, Eocene).
Holotype: Wrenn and Hart, 1988, fig.26, nos.1-2. N.I.A.
Age: Paleocene-Eocene.
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Impletosphaeridium lorum sp.
Figure 26.1-2
Diagnosis. A species of Impletosphaeridium characterized by acuminate, whip-like solid, but highly flexible, processes.
Description.
Shape: The central body is subspherical to ellipsoidal.
Phragma: The central body is less than 1 μm thick and is composed of an autophragm or closely appressed periphragm and endophragm. The surface texture of the central body is shagreenate to granular. The 50 to 100 nontabular processes are solid, whip-like, and distally acuminate. The processes appear to be highly flexible.
Paratabulation: None evident.
Paracingulum: None evident.
Parasulcus: None evident.
Archeopyle: None evident.
Dimensions. Observed range (four specimens): length, 21 to 33 (mean, 27 μm); width, 21 to 25 μm (mean, 22 μm): processes, 10 to 15
μm; autophragm, less than 1 μm thick.
Discussion and Comparison with Other Species. Although I. lorum sp. nov. superficially resembles I. ligospinosum (De Coninck) Islam, 1983, the former is characterized by whip-like acuminate processes. The processes of I. ligospinosum, on the other hand, are quite stiff, and their
terminations are bifid or capitate. I. lorum sp. nov. has fewer, longer processes (as much as 15 μm long) than Micrhystridium sp. A. The latter
has a dense covering of processes less than 8 μm long.
Holotype. Slide 8496, W/8, 114.2 x 20.7 (W19). Sample 8496, Section 16, Cross Valley Formation, early late Paleocene, Seymous Island, Antarctica.
Derivation of Name. Latin, lorum, whip or scourge, with reference to the whip-like processes.
Stratigraphic Occurrence. Cross Valley Formation (Section 12-13, Paleocene; Sections 15 and 16, early late Paleocene); La Meseta Formation
(Section 3, Eocene; Sections 17, 18, and 19, Eocene).