Working from deep geologic strata toward shallow geologic strata, what is the sequence in which fossils of these groups should make their first appearance?
1. charophytes
2. single-celled green algae
3. hornworts
4. plants with a dominant sporophyte
These are macrophytes that grow entire in the freshwater and become fossilized by the calcification oozes, going back to the Paleozoic era about 250 million years ago.
And they are unicellular to multi-cellular organisms also found in moist terrestrial habitats.