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Palaecysta palmula
Palaecysta palmula (Davey, 1982b, p.11–12, pl.1, figs.1–4) Williams and Fensome, 2016, p.140.
Originally Systematophora, subsequently (and now) Palaecysta.
This combination was not validly published in Chen (2013, p.293), since that author did not fully reference the basionym.
Chen (2013, p.293) listed some of his illustrations as paratypes; however, since Chen's paper does not constitute the protologue for this species, and as the illustations do not purport to be from Davey's (1982b) original study, they are not paratypes.
Holotype: Davey, 1982b, pl.1, figs.1–3; Fauconnier and Masure, 2004, pl.76, figs.11–13
Age: Ryazanian–Valanginian.
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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.
Systematophora palmula Davey, 1982b. Diagnosis from Davey (1982b, p.11-12). The body was originally spheroidal with only minor dorso-ventral flattening. The cyst wall is of moderate thickness and is apparently two-layered, the two layers being closely appressed except where the periphragm alone forms the processes. It is smooth to scabrate. The processes are smooth and may have internal vacuoles. The processes are basically of two types; the pre- and postcingular and antapical annulate processes being membranous and the apical, parasulcal and paracingular processes being simple. The proximal ridges of the annulate complexes tend to be arcuate and, in the pre- and postcingular series, are best developed on the side away from the paracingulum. The single membranous process arising from this arcuate ridge divides medially into two or more branches; additional branching may be present and the distal termination is a small bifurcation. The parasulcal processes are unbranched and solid; they gradually taper-distally to terminate with a small bifurcation. The apical processes are similar or slightly membranous. The paracingular processes occur in pairs, two per paraplate and each pair may be linked proximally by a ridge. Archeopyle apical type [tA]. Size: body diameter, excluding processes, length with archeopyle developed, 34-53 µm, width 39-48 µm, process length 18-38.
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Original diagnosis: Davey, 1982, p. 12-13
Shape: The body was originally spheroidal with only minor dorso-ventral flattening.
Wall: The cyst wall is of moderate thickness and is apparently two-layered, the two layers being closely appressed except where the periphragm alone forms the processes. It is smooth to scabrate. The processes are smooth and may have internal vacuoles.
Processes: These are basically of two types - the pre-, postcingular and antapical annulate processes being membranous and the apical, parasulcal and paracingular processes being simple. The proximal ridges of the annulate complexes tend to be arcuate and, in the pre- and postcingular series. are best developed on the side away from the paracingulum. The single membranous process arising from this arcuate ridge divides medially into two or more branches; additional branching may be present and the distal termination is a small bifurcation. The parasulcal processes are unbranched and solid: they gradually taper-distally to terminate with a small bituration. The apical processes are similar or slightly membranous. The paracingular processes occur in pairs, two per paraplate. and each pair may be linked proximally by a ridge.
Archaeopyle: An apical archaeopyle always appears to be developed by the detachment of the apical paraplates as a unit (Type A) It has a strongly zigzag margin.
Original description: Davey, 1982, p. 13
The width of the membranous processes varies considerably upon an individual specimen and from specimen to specimen. The largest ones, in the antapical and dorsal postcingular positions, divide medially into four to seven subparallel branches; the remaining postcingular processes and the precingular processes are less divided, typically two to four branches, and the division may commence in the lower part of the process.
Originally Systematophora, subsequently (and now) Palaecysta.
This combination was not validly published in Chen (2013, p.293), since that author did not fully reference the basionym.
Chen (2013, p.293) listed some of his illustrations as paratypes; however, since Chen's paper does not constitute the protologue for this species, and as the illustations do not purport to be from Davey's (1982b) original study, they are not paratypes.
Holotype: Davey, 1982b, pl.1, figs.1–3; Fauconnier and Masure, 2004, pl.76, figs.11–13
Age: Ryazanian–Valanginian.
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Systematophora palmula Davey, 1982b. Diagnosis from Davey (1982b, p.11-12). The body was originally spheroidal with only minor dorso-ventral flattening. The cyst wall is of moderate thickness and is apparently two-layered, the two layers being closely appressed except where the periphragm alone forms the processes. It is smooth to scabrate. The processes are smooth and may have internal vacuoles. The processes are basically of two types; the pre- and postcingular and antapical annulate processes being membranous and the apical, parasulcal and paracingular processes being simple. The proximal ridges of the annulate complexes tend to be arcuate and, in the pre- and postcingular series, are best developed on the side away from the paracingulum. The single membranous process arising from this arcuate ridge divides medially into two or more branches; additional branching may be present and the distal termination is a small bifurcation. The parasulcal processes are unbranched and solid; they gradually taper-distally to terminate with a small bifurcation. The apical processes are similar or slightly membranous. The paracingular processes occur in pairs, two per paraplate and each pair may be linked proximally by a ridge. Archeopyle apical type [tA]. Size: body diameter, excluding processes, length with archeopyle developed, 34-53 µm, width 39-48 µm, process length 18-38.
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Original diagnosis: Davey, 1982, p. 12-13
Shape: The body was originally spheroidal with only minor dorso-ventral flattening.
Wall: The cyst wall is of moderate thickness and is apparently two-layered, the two layers being closely appressed except where the periphragm alone forms the processes. It is smooth to scabrate. The processes are smooth and may have internal vacuoles.
Processes: These are basically of two types - the pre-, postcingular and antapical annulate processes being membranous and the apical, parasulcal and paracingular processes being simple. The proximal ridges of the annulate complexes tend to be arcuate and, in the pre- and postcingular series. are best developed on the side away from the paracingulum. The single membranous process arising from this arcuate ridge divides medially into two or more branches; additional branching may be present and the distal termination is a small bifurcation. The parasulcal processes are unbranched and solid: they gradually taper-distally to terminate with a small bituration. The apical processes are similar or slightly membranous. The paracingular processes occur in pairs, two per paraplate. and each pair may be linked proximally by a ridge.
Archaeopyle: An apical archaeopyle always appears to be developed by the detachment of the apical paraplates as a unit (Type A) It has a strongly zigzag margin.
Original description: Davey, 1982, p. 13
The width of the membranous processes varies considerably upon an individual specimen and from specimen to specimen. The largest ones, in the antapical and dorsal postcingular positions, divide medially into four to seven subparallel branches; the remaining postcingular processes and the precingular processes are less divided, typically two to four branches, and the division may commence in the lower part of the process.