Why Modern ferns horsetails and club misses are smaller than they were millions years ago Why might these plants be smaller?

Modern ferns, horsetails, and clubmosses are generally smaller than their prehistoric relatives due to significant changes in environmental conditions, including climate, soil composition, and competition with flowering plants. During the Carboniferous period, these plants thrived in a warm, humid climate, allowing for larger growth. As ecosystems evolved and conditions became less favorable for such large forms, these plants adapted to smaller sizes, which may also enhance their survival and reproductive success in diverse habitats. Additionally, genetic and evolutionary factors have played a role in shaping their current sizes.