Selaginella can be regarded as an evolutionary advanced Pteridophyte because of

Step-by-step solution

Heterospory is the occurrence of two types of spore, smaller microspore, and larger macrospore. Heterospory has led to the evolution of seed habit in plants. Heterospory first evolved in Pteridophyta in which megaspore was retained on parent sporophyte which is considered as a precursor to seed habit.