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Lanterna saturnalis
Lanterna? saturnalis Brideaux and Fisher, 1976
NOW Epiplosphaera. Originally Lanterna, subsequently Lanterna?, thirdly Pandadinium, fourthly (and now) Epiplosphaera. Questionable assignment: Stover and Evitt (1978, p.59).
Holotype: Brideaux and Fisher, 1976, pl.6, figs.1-7
Locus typicus: Elf Horton River, District of Franklin, Canada
Stratum typicum: Late Oxfordian-Late Kimmeridgian
Original diagnosis: Brideaux and Fisher, 1976, p. 24
Cyst length slightly greater than width; outline roughly truncated biconical. Periphragm and endophragm closely appressed throughout; periphragm produced into a densely spaced intratabular sculpture of varying process types, generally anastomosing basally and forming an irregular meshwork, but occasionally discrete. Archeopyle apical, formed by the loss of the reflected apical plate series in both wall layers; operculum simple, composed of both wall layers, occasionally partly attached, but generally detached. Reflected tabulation scheme determined as 4", 6", 0c, ?6""" , ?1p, ?1"""". Reflected cingulum outlined by parallel rows of processes of greater length than the intratabular processes; cingulum offset from one-half to three-quarters of the cingulum width. Sulcus generally indistinct; where discernible, following a relatively straight course from the antapex and reaching onto the epitract, terminating at the posterior edge of reflected plate 1".
Original description: Brideaux and Fisher, 1976, p. 24
The length of the cyst is slightly greater than the maximum width. The maximum width occurs at the latitude of the reflected cingulum, the cyst tapering and rounded at the apices to give a truncated biconical outline. The cyst outline probably explains the preferred apical-antapical orientation of most specimens. The periblast and endoblast are closely appressed and in contact throughout. The periphragm is thin, about 1.0 Ám thick in optical section and is produced into a dense cover of processes: the processes are intratabular and occasionally distinctly peritabular in position. They anastomose basally to form an irregular, perfect to imperfect reticulum or, less commonly, irregularly converging arcuate patterns. Occasionally, the processes are discrete and more widely spaced. The processes also may form irregular peritabular ridges by anastomosing basally and indistinctly or, rarely, distinctly, outlining reflected tabulation in part. Individual sculpture elements include simple, tapering spines, bifid or bifurcating processes, and flattened, irregularly foliate processes, 6-8 Ám in length, but longer, 7-12 Ám, at the antapex and along the reflected cingular ledges. The endophragm is thin, less than 1.0 Ám thick in optical section, and smooth. The archeopyle is apical and formed by the loss of four reflected apical plates in both layers. The operculum is simple, formed of both wall layers, and on some specimens remains partly attached. Isolated opercula have not been recognized. The outline of the archeopyle, the shape of the partly attached operculum and the presence of secondary archeopyle sutures indicate that the reflected epitractal tabulation comprises four apical reflected plates and six pre-cingular reflected plates. The reflected tabulation of the hypotract is less distinct. Arrangement of the processes and the occasional presence of peritabular ridges suggest, but do not confirm, a reflected hypotractal tabulation of 6", 1p, 1"""".
The reflected cingulum is defined by parallel rows of processes joined basally to form cingular ridges. The process elements are similar to those arising from intratabular and peritabular areas, except that they are slightly longer. The width of the reflected cingulum is about 5.0Á on specimens suitably oriented for measurement and the ventral terminations of the reflected cingulum are offset from one-half to three-quarters of the cingulum width. The reflected sulcus is indistinctly outlined on a few specimens by a broad lineation formed of the anastomosing bases of the hypotractal processes. The sulcus is set on the median line joining apex and antapex and terminates at the base of the reflected apical plate 1". On specimens preserved in apical orientation, the position of the sulcus is indicated in outline by an absence of cingular processes. This indentation corresponds, in several suitably oriented specimens, with the part of the rim of the primary archeopyle suture marking the posterior margin of reflected plate 1".
Dimensions: Cyst length, 70-80 µm; cyst width, 57-82 µm.
Affinities:
Brideaux and Fisher, 1976, p. 25: Lanterna saturnalis most closely resembles Lanterna sportula Dodekova (1969, p. 18, Pl. 3, figs. 4, 7, 10, 11), of previously described species of the genus. The two species are of similar size and general construction, but Lanterna saturnalis differs in having an imperfect to perfect reticulum formed by the anastomosing bases of processes compared with the rugulate to rugulo-reticulate pattern exhibited by L. sportula. Lanterna saturnalis also exhibits a truncated biconical outline and possesses distinctly longer processes at the antapex and along the cingular sutures. Lanterna sportula is more equidimensional.
NOW Epiplosphaera. Originally Lanterna, subsequently Lanterna?, thirdly Pandadinium, fourthly (and now) Epiplosphaera. Questionable assignment: Stover and Evitt (1978, p.59).
Holotype: Brideaux and Fisher, 1976, pl.6, figs.1-7
Locus typicus: Elf Horton River, District of Franklin, Canada
Stratum typicum: Late Oxfordian-Late Kimmeridgian
Original diagnosis: Brideaux and Fisher, 1976, p. 24
Cyst length slightly greater than width; outline roughly truncated biconical. Periphragm and endophragm closely appressed throughout; periphragm produced into a densely spaced intratabular sculpture of varying process types, generally anastomosing basally and forming an irregular meshwork, but occasionally discrete. Archeopyle apical, formed by the loss of the reflected apical plate series in both wall layers; operculum simple, composed of both wall layers, occasionally partly attached, but generally detached. Reflected tabulation scheme determined as 4", 6", 0c, ?6""" , ?1p, ?1"""". Reflected cingulum outlined by parallel rows of processes of greater length than the intratabular processes; cingulum offset from one-half to three-quarters of the cingulum width. Sulcus generally indistinct; where discernible, following a relatively straight course from the antapex and reaching onto the epitract, terminating at the posterior edge of reflected plate 1".
Original description: Brideaux and Fisher, 1976, p. 24
The length of the cyst is slightly greater than the maximum width. The maximum width occurs at the latitude of the reflected cingulum, the cyst tapering and rounded at the apices to give a truncated biconical outline. The cyst outline probably explains the preferred apical-antapical orientation of most specimens. The periblast and endoblast are closely appressed and in contact throughout. The periphragm is thin, about 1.0 Ám thick in optical section and is produced into a dense cover of processes: the processes are intratabular and occasionally distinctly peritabular in position. They anastomose basally to form an irregular, perfect to imperfect reticulum or, less commonly, irregularly converging arcuate patterns. Occasionally, the processes are discrete and more widely spaced. The processes also may form irregular peritabular ridges by anastomosing basally and indistinctly or, rarely, distinctly, outlining reflected tabulation in part. Individual sculpture elements include simple, tapering spines, bifid or bifurcating processes, and flattened, irregularly foliate processes, 6-8 Ám in length, but longer, 7-12 Ám, at the antapex and along the reflected cingular ledges. The endophragm is thin, less than 1.0 Ám thick in optical section, and smooth. The archeopyle is apical and formed by the loss of four reflected apical plates in both layers. The operculum is simple, formed of both wall layers, and on some specimens remains partly attached. Isolated opercula have not been recognized. The outline of the archeopyle, the shape of the partly attached operculum and the presence of secondary archeopyle sutures indicate that the reflected epitractal tabulation comprises four apical reflected plates and six pre-cingular reflected plates. The reflected tabulation of the hypotract is less distinct. Arrangement of the processes and the occasional presence of peritabular ridges suggest, but do not confirm, a reflected hypotractal tabulation of 6", 1p, 1"""".
The reflected cingulum is defined by parallel rows of processes joined basally to form cingular ridges. The process elements are similar to those arising from intratabular and peritabular areas, except that they are slightly longer. The width of the reflected cingulum is about 5.0Á on specimens suitably oriented for measurement and the ventral terminations of the reflected cingulum are offset from one-half to three-quarters of the cingulum width. The reflected sulcus is indistinctly outlined on a few specimens by a broad lineation formed of the anastomosing bases of the hypotractal processes. The sulcus is set on the median line joining apex and antapex and terminates at the base of the reflected apical plate 1". On specimens preserved in apical orientation, the position of the sulcus is indicated in outline by an absence of cingular processes. This indentation corresponds, in several suitably oriented specimens, with the part of the rim of the primary archeopyle suture marking the posterior margin of reflected plate 1".
Dimensions: Cyst length, 70-80 µm; cyst width, 57-82 µm.
Affinities:
Brideaux and Fisher, 1976, p. 25: Lanterna saturnalis most closely resembles Lanterna sportula Dodekova (1969, p. 18, Pl. 3, figs. 4, 7, 10, 11), of previously described species of the genus. The two species are of similar size and general construction, but Lanterna saturnalis differs in having an imperfect to perfect reticulum formed by the anastomosing bases of processes compared with the rugulate to rugulo-reticulate pattern exhibited by L. sportula. Lanterna saturnalis also exhibits a truncated biconical outline and possesses distinctly longer processes at the antapex and along the cingular sutures. Lanterna sportula is more equidimensional.