Back
Dioxya extensa
Dioxya? extensa (Stover, 1974) Morgan, 1977
Now Gippsandia. Originally Deflandrea, subsequently Vozzhennikoia?, thirdly Dioxya?, fourthly Lentinia, fifthly (and now) Gippslandia.
Lentin and Williams, 1981, questionably retained this species in Vozzhennikovia Lentin and Williams, 1976.
At the time of the transfer, Morgan, 1977, questionably included this species in Dioxya.
Holotypus: Stover, 1974, pl.5, figs.4a-c
Locus typicus: Glencoe-4 well, Australia
Stratum typicum: Middle to Late Eocene
Original diagnosis: Stover, 1974, p.178: Deflandrea extensa
Outline of periphragm in dorso-ventral view is broadly elliptical to ovoid with evenly convex lateral margins. Apical margin more convex than lateral margins and has a short apical horn at its apex, antapical margin concave with small horns developed at each corner (the right antapical horn is the larger). Periphragm is less than 1 Ám thick, spinose, spines mostly pointed, occasionally with bifurcate tips, 3-9 Ám long and fairly evenly spaced, except in the cingulum and sulcus which lack spines or have a few scattered spines.
Endoblast in dorso-ventral view almost completely fills the pericoel. Endophragm, which is about 0.5 Ám thick and is close to the periphragm, has an outline conformable with that of the latter, deviating only slightly at the bases of the apical and antapical horns.
Archeopyle intercalary, large, wider than long, has a trapezoidal outline with the base being wider than the apical margin. Operculum free. Tabulation is commonly abscure although outlines of some precingular and postcingular plates can be identified by the alignrnent of the spines, particularly on the dorsal surface of the epitract.
Dimensions: Specimens are 66-81 Ám long (mean 74 Ám) and 59-66 Ám wide (mean 62 Ám). Holotype is 72 Ám long, 65 Ám wide. Measurement based on 25 specimens.
Now Gippsandia. Originally Deflandrea, subsequently Vozzhennikoia?, thirdly Dioxya?, fourthly Lentinia, fifthly (and now) Gippslandia.
Lentin and Williams, 1981, questionably retained this species in Vozzhennikovia Lentin and Williams, 1976.
At the time of the transfer, Morgan, 1977, questionably included this species in Dioxya.
Holotypus: Stover, 1974, pl.5, figs.4a-c
Locus typicus: Glencoe-4 well, Australia
Stratum typicum: Middle to Late Eocene
Original diagnosis: Stover, 1974, p.178: Deflandrea extensa
Outline of periphragm in dorso-ventral view is broadly elliptical to ovoid with evenly convex lateral margins. Apical margin more convex than lateral margins and has a short apical horn at its apex, antapical margin concave with small horns developed at each corner (the right antapical horn is the larger). Periphragm is less than 1 Ám thick, spinose, spines mostly pointed, occasionally with bifurcate tips, 3-9 Ám long and fairly evenly spaced, except in the cingulum and sulcus which lack spines or have a few scattered spines.
Endoblast in dorso-ventral view almost completely fills the pericoel. Endophragm, which is about 0.5 Ám thick and is close to the periphragm, has an outline conformable with that of the latter, deviating only slightly at the bases of the apical and antapical horns.
Archeopyle intercalary, large, wider than long, has a trapezoidal outline with the base being wider than the apical margin. Operculum free. Tabulation is commonly abscure although outlines of some precingular and postcingular plates can be identified by the alignrnent of the spines, particularly on the dorsal surface of the epitract.
Dimensions: Specimens are 66-81 Ám long (mean 74 Ám) and 59-66 Ám wide (mean 62 Ám). Holotype is 72 Ám long, 65 Ám wide. Measurement based on 25 specimens.