miniature football from the Rhynie
looks here like a ball stitched together from polygonal patches is
really a solid sphere made of tightly fitting polyhedral alga cells. It
serves as the base of a whorl of charophyte branches.
polyhedral cells differ strongly from the big tube-like cells of the
branches. A few of the possibly 7 branches of this
whorl vanish in
the depth of the picture, hence Fig.1 is a tilted view from below. Apparently the
stem bearing the whorl has been cut off, thus is not seen here.
Fig.1: Multicellular globular base, 0.24mm,
of a charophyte whorl with branches
consisting of big cells, seen on a cut face of
a chert sample. Image height 1mm.
the charophyte algae in the Rhynie chert it is known that their stem
and branch segments consist of only one cell, like with extant Nitella, after
which the name Palaeonitella
had been coined . As pointed out before , this might not have
been an apt choice because some or even all of the algae
called Palaeonitella are
wide apart from Nitella
and all known charophytes in a phylogenetic
sense. (See also Rhynie
Chert News 93 .)
ball in Fig.1 is not a unique phenomenon. There are more of such but
less beautiful ones, as in Figs.2,3 (same scale as Fig.1).
Fig.2 (left): Charophyte whorl base
exposed as a cross-section,
seen from below, on
the raw sample surface.
Fig.3 (below): Multicellular base of a
charophyte whorl as seen just below the
raw sample surface, poorly preserved, no
Image height 0.25mm.
as with Fig.1, the well-preserved branches of the whorl seen from below
in Fig.2 are directed upward (into the
picture plane). The segmentation of the globule is faintly indicated.
Despite of the missing branches in Fig.3, this object, too, is
doubtless a charophyte whorl base.
These globules do not seem to be compatible with the detailed images of whorl bases in .
All pictures have been taken from a chert sample of 0.28kg found in
2003, labelled Rh9/86.
 R. Kidston, W.H. Lang:
On Old Red Sandstone plants … Part V,
Trans. Roy. Soc. Edinburgh 52(1921),
xanthophyte and new charophyte in the Rhynie chert.
87th Annual Conference of the
Paläontologische Gesellschaft, Dresden 2016.