Back
Filisphaera microornata
Filisphaera microornata (Head et al., 1989) Head (ed.) 1993
Holotype: Head et al., 1989, pl.5, fig.1-3,5
Locus typicus: ODP leg 105, site 646
Stratum typicum: Early Pliocene
Original diagnosis: Head et al., 1989, p.458: Muraticysta microornata
Cysts spherical to ovoidal with a closely appressed biphragmal wall. Endophragm thinner than periphragm, which forms a smooth reticulate ornament of fine, delicate sinuous muri 2-3 Ám high that have slightly undulating crest tops. Lacunae have an irregular polygonal outline and are about 1.5-3.5 Ám wide. Archeopyle precingular Type P (presumably Type P3'') and large. Operculum free. There is no other indication of paratabulation.
Dimensions. Holotype: maximum diameter, 57 Ám. Range of maximum diameter, 53(58)62 Ám; muri 2-3 Ám high and 0.2-0.5 Ám wide. Nine specimens were measured.
Remarks. In all specimens where the archeopyle could be recognized, Type P was observed.
Affinities:
Head et al., 1989, p.458-459: This species is similar in size and shape to Filisphara filifera Bujak, 1984 and differs in having a finely reticulate periphragm, compared to the radially fibrous periphragm of F. filifera (Bujak, 1984, p. 185). However, these two species may appear similar under low magnification. F. filifera may also possess a small apical lobe, and the archeopyle may involve the loss of one or two precingular paraplates. It was not possible to determine whether a slight apical lobe is present in M. microornata n. sp. because of the folded condition of most specimens encountered.
Modified Description. Head (ed.) 1993, p. 237-238
Cysts spherical to ovoidal with a closely appressed biphragmal wall. Endophragm thinner than periphragm, which forms a smooth reticulate ornament of fine, delicate sinuous septa about 1.5-2.3 high that have straight to slightly undulating crest tops. Each specimen shows a range of lumen sizes from about 0.5Ám or less to a maximum of about 2.0-3.4Ám. Lumina range in shape from irregularly polygonal to narrow and sinuous, this range usually occurring on each specimen. Archeopyle precingular Type P (presumably Type P3) or possibly 2P, and large; angles pronounced. Operculum free. There are no other indications of paratabulation.
Dimensions (Revised). Holotype: maximum diameter (including periphragm), 59 Ám. Maximum diameter of largest lumina, ca. 2.9 Ám. Height of septa, ca. 1.7 Ám. Thickness of septa, ca.0.3Ám. Range: maximum diameter (including periphragm),49 (58.9) 65Ám. Maximum diameter of larger lumina, ca. 2.0-2.5 (rarely up to 3.4 Ám). Height of septa, ca. l .5-2.3 Ám. Thickness of septa, ca.0.2-0.3 Ám. Nine specimens were measured.
Remarks. Head (ed.) 1993, p. 237-238
Originally described under the name Muraticysta microornata Head et al. l 989, this species now falls within the genus Filisphaera as presently emended and is here transferred accordingly. Type specimens from the Upper Miocene or Lower Pliocene of the Labrador Sea (Samples ODP-105-646B-51X-2, 21-26 cm and -646B-SOX-1, 131-135 cm) have been re-examined and re-measured. Re-examination shows the septa to be somewhat lower (ca. 1.5-2.3 Ám) than originally estimated (2-3Ám high; Head et al.,1989a). The modified description takes account of this observation and expresses more precisely the shape and size distribution of lumina in the microreticulate periphragm. Despite difficulties caused by crumpled preservation of most specimens, a precingular archeopyle Type lP was determined for one at least one specimen; a Type 2P possibly occurs on others.
Comparison. Head (ed.) 1993, p. 237-238
Filisphaera microornata is distinguished from F. filifera in having coarser microreticulation of the periphragm: maximum diameter of larger lumina generally about 2.0-2.5Ám for F. microornata.versus about 2.0Ám or less for F. filifera. Filisphaera microornata usually also has fewer small (ca. 0.5 Ám) lumina than Filisphaera filifera.
Occurrence. Filisphaera microornata was described in deposits of Late Pliocene (Baldauf et al., 1989) or Early Miocene (Aksu and Kaminski, 1989) age from the Ocean Drilling Program Hole 646B, Labrador Sea (Head et al., 1989a) where it occurs within Nannofossil zone NN12 (Knuttel et al., 1989). It has also been recorded from the Lower? Pliocene, Upper Pliocene, and Lower Pleistocene? of Baffin Bay (Samples ODP-105-645B-30X, CC through -645B-22X-4; 109-111 cm, and 645D-1 lR-4; 78-80 cm through 645D-2R-4; 83-85 cm; as Filisphaera sp. cf. F. microornata in Anstey, 1992).
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Filisphaera microornata (Head et al., 1989b) Head, 1994b. According to Head (1994b, p.237) has cysts that are spherical to ovoidal with closely appressed biphragmal wall. Endophragm thinner than periphragm, which forms a smooth reticulate ornament of fine, delicate sinuous septa about 1.5-2.3 µm high that have straight to slightly undulating crest tops. Each specimen shows a range of lumen sizes from about 0.5 µm or less to a maximum of about 2.0-3.4 µm. Lumina range in shape from irregularly polygonal to narrow and sinuous, this range usually occurring on each specimen. Archeopyle precingular type P or possibly 2P, and large. Angles pronounced. Operculum free. This species differs from F. filifera in having coarser microreticulation of the periphragm: maximum diameter of larger lumina generally about 2.0-2.5 µm for F. microornata versus about 2.0 µm or less for F. filisphaera. F. microornata usually also has fewer small (ca. 0.5 µm) lumina than F. filisphaera. Dimensions: maximum diameter 49-65 µm, maximum diameter of larger lumina 2-2.5 µm, rarely 3.4 µm., height of septa 1.5-2.3 µm. Thickness of septa ca 0.2-0.3 µm.
Holotype: Head et al., 1989, pl.5, fig.1-3,5
Locus typicus: ODP leg 105, site 646
Stratum typicum: Early Pliocene
Original diagnosis: Head et al., 1989, p.458: Muraticysta microornata
Cysts spherical to ovoidal with a closely appressed biphragmal wall. Endophragm thinner than periphragm, which forms a smooth reticulate ornament of fine, delicate sinuous muri 2-3 Ám high that have slightly undulating crest tops. Lacunae have an irregular polygonal outline and are about 1.5-3.5 Ám wide. Archeopyle precingular Type P (presumably Type P3'') and large. Operculum free. There is no other indication of paratabulation.
Dimensions. Holotype: maximum diameter, 57 Ám. Range of maximum diameter, 53(58)62 Ám; muri 2-3 Ám high and 0.2-0.5 Ám wide. Nine specimens were measured.
Remarks. In all specimens where the archeopyle could be recognized, Type P was observed.
Affinities:
Head et al., 1989, p.458-459: This species is similar in size and shape to Filisphara filifera Bujak, 1984 and differs in having a finely reticulate periphragm, compared to the radially fibrous periphragm of F. filifera (Bujak, 1984, p. 185). However, these two species may appear similar under low magnification. F. filifera may also possess a small apical lobe, and the archeopyle may involve the loss of one or two precingular paraplates. It was not possible to determine whether a slight apical lobe is present in M. microornata n. sp. because of the folded condition of most specimens encountered.
Modified Description. Head (ed.) 1993, p. 237-238
Cysts spherical to ovoidal with a closely appressed biphragmal wall. Endophragm thinner than periphragm, which forms a smooth reticulate ornament of fine, delicate sinuous septa about 1.5-2.3 high that have straight to slightly undulating crest tops. Each specimen shows a range of lumen sizes from about 0.5Ám or less to a maximum of about 2.0-3.4Ám. Lumina range in shape from irregularly polygonal to narrow and sinuous, this range usually occurring on each specimen. Archeopyle precingular Type P (presumably Type P3) or possibly 2P, and large; angles pronounced. Operculum free. There are no other indications of paratabulation.
Dimensions (Revised). Holotype: maximum diameter (including periphragm), 59 Ám. Maximum diameter of largest lumina, ca. 2.9 Ám. Height of septa, ca. 1.7 Ám. Thickness of septa, ca.0.3Ám. Range: maximum diameter (including periphragm),49 (58.9) 65Ám. Maximum diameter of larger lumina, ca. 2.0-2.5 (rarely up to 3.4 Ám). Height of septa, ca. l .5-2.3 Ám. Thickness of septa, ca.0.2-0.3 Ám. Nine specimens were measured.
Remarks. Head (ed.) 1993, p. 237-238
Originally described under the name Muraticysta microornata Head et al. l 989, this species now falls within the genus Filisphaera as presently emended and is here transferred accordingly. Type specimens from the Upper Miocene or Lower Pliocene of the Labrador Sea (Samples ODP-105-646B-51X-2, 21-26 cm and -646B-SOX-1, 131-135 cm) have been re-examined and re-measured. Re-examination shows the septa to be somewhat lower (ca. 1.5-2.3 Ám) than originally estimated (2-3Ám high; Head et al.,1989a). The modified description takes account of this observation and expresses more precisely the shape and size distribution of lumina in the microreticulate periphragm. Despite difficulties caused by crumpled preservation of most specimens, a precingular archeopyle Type lP was determined for one at least one specimen; a Type 2P possibly occurs on others.
Comparison. Head (ed.) 1993, p. 237-238
Filisphaera microornata is distinguished from F. filifera in having coarser microreticulation of the periphragm: maximum diameter of larger lumina generally about 2.0-2.5Ám for F. microornata.versus about 2.0Ám or less for F. filifera. Filisphaera microornata usually also has fewer small (ca. 0.5 Ám) lumina than Filisphaera filifera.
Occurrence. Filisphaera microornata was described in deposits of Late Pliocene (Baldauf et al., 1989) or Early Miocene (Aksu and Kaminski, 1989) age from the Ocean Drilling Program Hole 646B, Labrador Sea (Head et al., 1989a) where it occurs within Nannofossil zone NN12 (Knuttel et al., 1989). It has also been recorded from the Lower? Pliocene, Upper Pliocene, and Lower Pleistocene? of Baffin Bay (Samples ODP-105-645B-30X, CC through -645B-22X-4; 109-111 cm, and 645D-1 lR-4; 78-80 cm through 645D-2R-4; 83-85 cm; as Filisphaera sp. cf. F. microornata in Anstey, 1992).
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Filisphaera microornata (Head et al., 1989b) Head, 1994b. According to Head (1994b, p.237) has cysts that are spherical to ovoidal with closely appressed biphragmal wall. Endophragm thinner than periphragm, which forms a smooth reticulate ornament of fine, delicate sinuous septa about 1.5-2.3 µm high that have straight to slightly undulating crest tops. Each specimen shows a range of lumen sizes from about 0.5 µm or less to a maximum of about 2.0-3.4 µm. Lumina range in shape from irregularly polygonal to narrow and sinuous, this range usually occurring on each specimen. Archeopyle precingular type P or possibly 2P, and large. Angles pronounced. Operculum free. This species differs from F. filifera in having coarser microreticulation of the periphragm: maximum diameter of larger lumina generally about 2.0-2.5 µm for F. microornata versus about 2.0 µm or less for F. filisphaera. F. microornata usually also has fewer small (ca. 0.5 µm) lumina than F. filisphaera. Dimensions: maximum diameter 49-65 µm, maximum diameter of larger lumina 2-2.5 µm, rarely 3.4 µm., height of septa 1.5-2.3 µm. Thickness of septa ca 0.2-0.3 µm.