While the Higher Plants make up only one big branch of the
profusely branched phylogenetic tree of life, the term "Lower Plants"
is traditionally used as a receptacle for all the rest, with the
exception of the animals and sometimes of the
fungi. (It is recommended to look up phylogenetic
trees in the recent literature although they may more or less differ
among themselves and have to be repeatedly adjusted to latest
discoveries.) The enigmatic nematophytes, which are known as fossils
only and had not yet got a place on the phylogenetic tree, have
been placed near to the Rhodophyta, based on fossil evidence.
The traditional sorting into apparently obvious clades is not at all
adequate to the forms of life
with several fundamentally
different structures on the cellular level
but it may be justified for purposes like the present one.
The number of Lower Plant species
found in the Rhynie chert exceeds that of the Higher Plants found
will increase further. The
species described hitherto represent the following clades:
= Cyanophytes =
Yellow-Green Algae =
Lower Plants seem to be scarce in cherts from other locations.
There are several good reasons for the assumption that the Higher
Plants have evolved from some Green Alga.
Arbitrarily selected Lower Plants from the Rhynie chert:
- Higher Plant Horneophyton
disguised as a monster with a fluffy fur consisting of the cyanophyte
width of the picture 10mm,
- probably the first fossil xanthophyte as shown in Rhynie
Chert News 69 (no image here),
- Palaeonitella , one of the
most advanced Green Algae, a charophyte apparently related to extant Nitella,
seen here hollow in the chert,
- a recently discovered Green Alga with peculiar "flowers", possibly an unknown type of charophyte
as described in
Chert News 73, 89, 90, 93, width of the picture 1mm.