Reduviasporonites catenulatus
Reduviasporonites catenulatus
Wilson 1962
1967 Reduviasporonites catenulatus Wilson 1962 - Morgan;
pl. 1, fig. 1
Description
(Also see Wilson, 1962)
Microfossil, usually forming chains, but also present
as pairs of cells or single dispersed cells. Cell outline subcircular
or subrectangular; probably originally sub-spherical before compression.
Outer cell wall approximately 1µm thick, smooth; may be irregularly
thickened at the margins; no inner body or cell material has been
observed. Cells in a chain, and particularly single unattached cells,
have regular concentric or subpolygonal fold patterns. Method of
cell-to-cell attachment not known, though some chains appear to
indicate that the convexity of part of a given cell fits into a
corresponding hemispherical concavity in an adjacent cell. No terminal
rims are present.
Remarks
See Foster et al. (in prep.).
Dimensions
See details of specimens.
Range
Permian (for full discussion see Foster et al., in prep.).
Reduviasporonites chalastus
Reduviasporonites chalastus
(Foster) Elsik 1999
1979 Chordecystia chalasta Foster: p. 109-110; pl. 41, figs.
3-9; text-fig. 22
Diagnosis
(From Foster, 1979).
Microfossils occurring in chains of two to six
individuals or, more commonly as discrete cells. Median members
of chain are cylindrical with an elongate rectangular outline in
surface view. Terminal members are ellipsoidal to club-shaped. Termini
of cells intact; invaginated or convex depending upon position in
chain; often slightly thicker and narrower at points of interconnection.
Wall one-layered; usually 2µm thick (rarely 1µm). A single fold
often extends over the full length of cell; it appears to be a compressional
feature. One or two narrow clefts or grooves, each 1–2 µm in width,
are apparent on most individuals. The clefts, which may delimit
a dehiscence area, extend diagonally between termini of cell or
from one end to approximately midway along opposite wall of cell
(surface view).
Description
(From Foster, 1979).
Microfossil, usually forming chains but also present
as pairs of cells or single dispersed cells. Cell outline subrectangular,
rarely oval, irregular or 'Y' shaped, though most cells were probably
originally cylindrical in shape before compression. Outer cell wall
approximately 0.5µm to 1.5µm thick, smooth; may be slightly thickened
in the regions of the terminal rims. The inner body commonly has
the same shape as the outer cell and may be adpressed to the inner
surface of the main cell so that it is difficult to distinguish
optically. The inner body may also occupy a smaller part of the
cell cavity (?through shrinkage) and may be twisted. Detachment
of the two walls appears first to occur in the middle parts; usually
the termini of the inner body are firmly attached to the inner surface
of the terminal rim, though detachment at these points may also
occur. Wall of inner body 0.5 to 1µm thick where observed, smooth,
sometimes hyaline in appearance. Dark 'cell material' of amorphous
or granulate appearance occurs in many specimens and is often enveloped
by the delicate, shrunken inner body. Cell has a number of characteristic
folding patterns. The diagonal folding pattern noted by Foster (1979)
is caused by twisting of the cell body about the long axis of the
cell. Other folds, in either of the cell walls, commonly delineate
rectilinear shapes and these may represent areas of residual attachment
of the inner and outer cell walls. Commonly, short lunate folds,
orientated perpendicular to the long axis of the cell, occur close
to the margins of ovoid cells. These are believed to result from
the attachment of the termini of the inner body to the inner surface
of the outer body and as such may represent parts of a poorly developed
terminal rim.
Remarks
See Foster et al. (in prep.).
Dimensions
See details of specimens.
Range
Permian-Triassic (for full discussion see Foster et al., in
prep.).
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