What can scientist infer about the period of very early Earth from the fossilized remains of trees found under a lake?

There is a theory that terrestrial plants evolved from aquatic plants through a process of natural selection. Thus, by finding fossils of plants under the river, scientists may conclude that this theory is correct and that these fossils represent the ancestors of terrestrial plants.

The emergence of plants that survive on earth is a very important milestone for the planet, it is believed that these plants have evolved from green algae called Chlorophyta that have survived in marshy areas that had alternating periods of flooding and drought. Then the discovery of these fossils, through scientific experiments may conclude that the theory is correct.