A friend of mine was telling me about a story where a man clear cut a diverse ecosystem of plants in an area similar to size and shape of a small caldera (not necessarily a caldera itself). Eventually, he noticed other plants were sprouting up that no one has ever seen before, as they were ancient seeds dormant beneath the surface waiting for the perfect conditions to sprout.
I've searched the internet for this story or something like it, and can't seem to find it. All I found out is that some people have grown some plants from ancient seeds.
I was thinking if this were to happen on a large scale, globally speaking, I wonder if it could set the perfect conditions for ancient seeds to grow. Example, like some seeds of megaflora from the Mesozoic period buried deep within subsoil. With the proper amount of churning up of topsoil and subsoil, and the decimation of preexisting plant life, I'm fascinated with the idea of some prehistoric giant trees growing after the earth is fallow for a few centuries after such an event.
Picture shown for reference. Taken from this site. Although a similar topic, does not reflect the nature of this post.
For clarification, this question is posted in search for a more descriptive support to the background of a world in which this scenario did happen - a purely fictional world. Not necessarily relating to seeds from a specific prehistoric time period, but ancient nonetheless. As though it could happen... perhaps?