Green Algae
Contrary to common belief, Green Algae do not mainly appear as big
slimy lumps of filaments in ponds but also in drier habitats.
Paradoxically, they
even appear as red stain on tree trunks and rocks. It must be
mentioned that the Yellow-Green Algae
are not included here, and the Blue-Green Algae
are widely separated from the Green Algae on the
phylogenetic tree.
Filamentous Green Algae are rare in the Rhynie
chert [1] and not easily found. The
alga in the image on the right, frame width 0.2mm, differs from the few
species described earlier. It resembles a similar one recently
described but not named in [1]. See
Rhynie
Chert News 140 .
Much more conspicuous than the filamentous
Green Algae are the charophytes, which are most easily recognised when
they present themselves as stems with whorls of branches, as
illustrated here under the inclusive term Lower Plants
and in the image on the left (frame width 1.5mm).
A recently discovered early
charophyte type of Green
Alga
with peculiar "flowers" (frame
1.5mm) is described in Rhynie
Chert News 73,
89, 90,
93, 106,
129,
138,
139, 
169.
This discovery
is thought to be essential for the
phylogenetic tree of the charophytes whose details are
relevant for the
evolutionary path to the
Higher Plants.
Green Algae consisting of big tubes but without
whorls of branches are more problematic but probably
are charophytes as well:
Rhynie
Chert News 48,
141.
(Image on the far right, frame width 0.5mm.)
[1] C.H.
Wellmann, L.E. Graham, L.A. Lewis: Filamentous
green algae from the Early Devonian Rhynie chert. PalZ 93, 387–393
(2019).
2021