It is a perfect example of a natural selection.
(I'm not sure if this is the exact answer that you are looking for.)
Am certain that the factor that prevents us from finding fossils from the Precambian era is that Most rocks from that era are deeply buried. The precambrian is the informal name for the large expanse of time preceding the current Phanerozoic Eon. It began with the Earh's Formation about 4.5 billion years ago and lasted until the advent of multicellular life about 542 million years ago.
Answer:
I wouldn't know
Explanation:
I would love to answer this question for you, sadly you have not provided us with the diagram. So I am not able to see which type of plant experienced a drought.