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Phoberocysta burgeri
Phoberocysta burgeri Helby, 1987
Tax. jr. synonym of Muderongia testudinaria Burger, 1980, according to Monteil, 1991.
Holotype: Helby, 1987, figs. 10A-C
Age: Latest Valanginian-Hauterivian
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Phoberocysta burgeri Helby, 1987. This species has two antapical horns, commonly symmetrical and is large, up to 225 microns. The paracingular horns are notched laterally, denoting the location of the cingular paraplates. It differs from Muderongia testudinaria in having well-developed parasutural features, particularly prominent spines. Phoberocysta neocomica differs in having a markedly reduced right antapical horn and in the absence or minor development of antapically inclined extensions of the postcingular paraplates on the cingular horns. Phoberocysta edgellii has very reduced cingular horns. According to Monteil (1991b), this is a taxonomic junior synonym of Muderongia testudinaria. Size: overall width 126-225 µm, width less horns 69-97, length loisthocyst 95-135 µm, length endocyst 67-87 µm, length cingular horns 25-33 µm.
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Holotype: Helby, 1987, figs10A-C
Locus typicus: Resolution-l well, 1976m, Australia
Stratum typicum: Valanginian-Hauterivian
Original description: Helby, 1987, p.307-308
Proximochorate cyst, dorsoventrally flattened, rhomboidal body outline with apical horn, 2 cingular horns and 2 antapical horns (in many specimens both the cingular horns and less commonly the antapical horns are essentially symmetrical). Cingular horns distinctive, projecting laterally from the paracingulum and comprised of parts of 2 laterally elongate paraplates from each of precingular and postcingular series and a very elongate 2c paraplate on the left side and 2 cingular paraplates (4c and 5c) on the right horn. Postcingular paraplates extending furthest from the cyst body, and lateral extension of these paraplates elongated and tapering away from plane of paracingulum, usually posteriorly although in some specimens these extensions may curl apically (Fig. 10F). Junction of paraplate series on paracingulal horns slightly ridged and expressed at lateral edge of horn boss by a pair of notches, one on each side of the paracingulum; lateral edges of cingular paraplates characteristically concave between these notches. Antapical horns variable in shape and length, usually tapered, and occasionally of equal length. If antapical horns unequal left horn usually longer. Apical horn usually long and gently tapered. Cyst wall 2-layered, cavation most obvious in the vicinity of the horns. Endocyst shape more or less rhomboidal, interrupted in some specimens by much reduced horn development (Fig.10C,D). Periphragm ornamentation variable; smooth, scabrate, granulate and perforate, with prominent parasutural, penitabular and intratabular spines (up to 1.5 µm in length). Endophragm smooth, scabrate or granulate. Paratabulation indicated by archeopyle, parasutural and penitabular ridging surmounted by long spines, and distinct paracingulum. In the middorsal regions, between 2'',3'' and 4'' and also between 2''', 3''', 4''', and 1'''' the ridges are clearly penitabular with separation up to 5 µm. Separation diminishing towards equator and onto ventral surface where the ridges appear to be parasutural. Ridges bordering the paracingulum also parasutural. Paratabulation formula 4', 6", 6c, 6''', 1p, 1'''' (Fig.11). Archeopyle apical, type [tA], principal archeopyle suture zigzag with offset parasulcal notch. Operculum free. Paracingulum indicated by cingular horns, and as transverse feature, particularly on the dorsal surface. Parasulcus often clear, sinuous, offset from midventral position on hypocyst to left ventral position on epicyst. Parasulcal paraplates occasionally evident.
Affinities:
Helby, 1987, p.309: Phoberocysta burgeri closely resembles M. testudinaria Burger 1980 but is distinguished by having well-developed parasutural features, particularly prominent spines. Phoberocysta neocomica is distinguished by the marked reduction of the right antapical horn, and by the absence or minor development of antapically inclined extensions of the postcingular paraplates on the cingular horns. Phoberocysta edgellii Iacks the distinctive, strongly developed, cingular horns and has larger, more numerous parasutural and intratabular spines.
Tax. jr. synonym of Muderongia testudinaria Burger, 1980, according to Monteil, 1991.
Holotype: Helby, 1987, figs. 10A-C
Age: Latest Valanginian-Hauterivian
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Phoberocysta burgeri Helby, 1987. This species has two antapical horns, commonly symmetrical and is large, up to 225 microns. The paracingular horns are notched laterally, denoting the location of the cingular paraplates. It differs from Muderongia testudinaria in having well-developed parasutural features, particularly prominent spines. Phoberocysta neocomica differs in having a markedly reduced right antapical horn and in the absence or minor development of antapically inclined extensions of the postcingular paraplates on the cingular horns. Phoberocysta edgellii has very reduced cingular horns. According to Monteil (1991b), this is a taxonomic junior synonym of Muderongia testudinaria. Size: overall width 126-225 µm, width less horns 69-97, length loisthocyst 95-135 µm, length endocyst 67-87 µm, length cingular horns 25-33 µm.
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Holotype: Helby, 1987, figs10A-C
Locus typicus: Resolution-l well, 1976m, Australia
Stratum typicum: Valanginian-Hauterivian
Original description: Helby, 1987, p.307-308
Proximochorate cyst, dorsoventrally flattened, rhomboidal body outline with apical horn, 2 cingular horns and 2 antapical horns (in many specimens both the cingular horns and less commonly the antapical horns are essentially symmetrical). Cingular horns distinctive, projecting laterally from the paracingulum and comprised of parts of 2 laterally elongate paraplates from each of precingular and postcingular series and a very elongate 2c paraplate on the left side and 2 cingular paraplates (4c and 5c) on the right horn. Postcingular paraplates extending furthest from the cyst body, and lateral extension of these paraplates elongated and tapering away from plane of paracingulum, usually posteriorly although in some specimens these extensions may curl apically (Fig. 10F). Junction of paraplate series on paracingulal horns slightly ridged and expressed at lateral edge of horn boss by a pair of notches, one on each side of the paracingulum; lateral edges of cingular paraplates characteristically concave between these notches. Antapical horns variable in shape and length, usually tapered, and occasionally of equal length. If antapical horns unequal left horn usually longer. Apical horn usually long and gently tapered. Cyst wall 2-layered, cavation most obvious in the vicinity of the horns. Endocyst shape more or less rhomboidal, interrupted in some specimens by much reduced horn development (Fig.10C,D). Periphragm ornamentation variable; smooth, scabrate, granulate and perforate, with prominent parasutural, penitabular and intratabular spines (up to 1.5 µm in length). Endophragm smooth, scabrate or granulate. Paratabulation indicated by archeopyle, parasutural and penitabular ridging surmounted by long spines, and distinct paracingulum. In the middorsal regions, between 2'',3'' and 4'' and also between 2''', 3''', 4''', and 1'''' the ridges are clearly penitabular with separation up to 5 µm. Separation diminishing towards equator and onto ventral surface where the ridges appear to be parasutural. Ridges bordering the paracingulum also parasutural. Paratabulation formula 4', 6", 6c, 6''', 1p, 1'''' (Fig.11). Archeopyle apical, type [tA], principal archeopyle suture zigzag with offset parasulcal notch. Operculum free. Paracingulum indicated by cingular horns, and as transverse feature, particularly on the dorsal surface. Parasulcus often clear, sinuous, offset from midventral position on hypocyst to left ventral position on epicyst. Parasulcal paraplates occasionally evident.
Affinities:
Helby, 1987, p.309: Phoberocysta burgeri closely resembles M. testudinaria Burger 1980 but is distinguished by having well-developed parasutural features, particularly prominent spines. Phoberocysta neocomica is distinguished by the marked reduction of the right antapical horn, and by the absence or minor development of antapically inclined extensions of the postcingular paraplates on the cingular horns. Phoberocysta edgellii Iacks the distinctive, strongly developed, cingular horns and has larger, more numerous parasutural and intratabular spines.