Two groups of fossil floras can be distinguished:
I. floras representing marsh vegetations
II. floras representing vegetations growing outside the actual
As to the second group plant remains deposited via a river in
a lake or delta come to mind.
The known floras of the Upper Carboniferous belong nearly all
to the first group, those of the Permian mainly to the second one. The
possibilities for fossilisation in the first group were much better than
those in the second group. The beautifully preserved and abundant coal fossils
In the second group the plant remains covered a long distance in the water
before they were deposited in the sediment. That is the reason they are often
The sediment with the Lodève flora is a lake deposition. Especially
the tough plant remains, like branches of conifers are well represented.
Ferns are very rare: these could obviously not stand the transportation.
Small conifer twigs could have been blown into the water during storms.
The floras of the Carboniferous generally grew in
a very humid environment. The conifer dominated Permian floras represent
a completely different environment. Generally speaking: the number of humidity
loving vegetations decreased strongly in the course of time and the vegetations
adapted to dryer circumstances came more and more to the forefront in the