Back
Phoberocysta edgellii
Phoberocysta edgellii Helby, 1987
Tax. jr. synonym of Muderongia testudinaria Burger, 1980, according to Monteil, 1991
Holotype: Helby 1987, fig.12D-F
Locus typicus: Australia
Stratum typicum: Hauterivian
Original description: Helby, 1987, p. 309-310
Proximochorate cyst, dorsoventrally flattened with rhomboidal body outline
interrupted by an apical horn, 2 cingular horns and 2 antapical horns. Cingular horns as short, stout, lateral bosses projecting from the paracingulum. Right cingular horn often larger than the left cingular horn. Edges of the cingular horns irregular due to a concentration of parasutural spines. However, on some specimens parasutural ridges allow recognition of the plate series. Left antapical horn often larger than the right although in some specimens the antapical horns appear symmetrical, tapering irregularly from a relatively broad base. Cyst wall 2-layered, cornucavate, but with distinct cavation evident only at the horns. Endocyst rhomboidal with gentle protrusions at the horns, often with eccentric antapex due to longer left horn (Fig.13H). Periphragm smooth scabrate or granular (occasionally perforate at extremities) with numerous, long (up to 18µm), thin, solid, parasutural spines, commonly surmounting parasutural ridges. Nontabular spines are common. Endophragm is up to 1.5µm thick, granulate to coarsely verrucate (at horn locations). Paratabulation clearly indicated by archeopyle, by parasutural ridges with cresting spines, and by the paracinuulum. Archeopyle apical, type [tA], principal archeopyle suture zigzag with parasulcal notch set off to left side. Paracingulum expressed as transverse feature across dorsal surface clearly delineated by parasutural ridges and spines, not particularly well defined at lateral edge of cingular horns, markedly offset on ventral surface. Parasulcus sinuous offset from a midventral position on the hypocyst to a left ventral position on the epicyst. Sulcal paraplates not distinguished. Measurements.
Affinities:
Helby, 1987, p. 310: Phoberocysta edgellii is distinguished from P. burgeri by the distinctive, well-developed cingular horns of the latter form which also exhibits fewer, more widely spaced parasutural spines. Australian populations of P. neocomica lack well-developed right antapical horns, have distinctive Muderongia-style cingular horns and are characterized by having major gonal spines, with only limited intergonal spine development.
Tax. jr. synonym of Muderongia testudinaria Burger, 1980, according to Monteil, 1991
Holotype: Helby 1987, fig.12D-F
Locus typicus: Australia
Stratum typicum: Hauterivian
Original description: Helby, 1987, p. 309-310
Proximochorate cyst, dorsoventrally flattened with rhomboidal body outline
interrupted by an apical horn, 2 cingular horns and 2 antapical horns. Cingular horns as short, stout, lateral bosses projecting from the paracingulum. Right cingular horn often larger than the left cingular horn. Edges of the cingular horns irregular due to a concentration of parasutural spines. However, on some specimens parasutural ridges allow recognition of the plate series. Left antapical horn often larger than the right although in some specimens the antapical horns appear symmetrical, tapering irregularly from a relatively broad base. Cyst wall 2-layered, cornucavate, but with distinct cavation evident only at the horns. Endocyst rhomboidal with gentle protrusions at the horns, often with eccentric antapex due to longer left horn (Fig.13H). Periphragm smooth scabrate or granular (occasionally perforate at extremities) with numerous, long (up to 18µm), thin, solid, parasutural spines, commonly surmounting parasutural ridges. Nontabular spines are common. Endophragm is up to 1.5µm thick, granulate to coarsely verrucate (at horn locations). Paratabulation clearly indicated by archeopyle, by parasutural ridges with cresting spines, and by the paracinuulum. Archeopyle apical, type [tA], principal archeopyle suture zigzag with parasulcal notch set off to left side. Paracingulum expressed as transverse feature across dorsal surface clearly delineated by parasutural ridges and spines, not particularly well defined at lateral edge of cingular horns, markedly offset on ventral surface. Parasulcus sinuous offset from a midventral position on the hypocyst to a left ventral position on the epicyst. Sulcal paraplates not distinguished. Measurements.
Affinities:
Helby, 1987, p. 310: Phoberocysta edgellii is distinguished from P. burgeri by the distinctive, well-developed cingular horns of the latter form which also exhibits fewer, more widely spaced parasutural spines. Australian populations of P. neocomica lack well-developed right antapical horns, have distinctive Muderongia-style cingular horns and are characterized by having major gonal spines, with only limited intergonal spine development.