Cryptogams through time evolutionary stability, ecological resilience, and bioindication in extreme environments

Abstract

Cryptogams - including bryophytes, lichens, pteridophytes, algae, and fungi - are primitive plant organisms that have persisted since the Paleozoic era, playing a central role in terrestrial colonization and the formation of early ecosystems. This research explores their ecological and evolutionary significance, as well as their potential as environmental bioindicators. Fossil records from Cretaceous and Mesozoic strata, along with Miocene neotropical amber, reveal morphological and functional stability, with lineages such as Frullania and Parmotrema occupying moist niches similar to those found today. Their lack of vascular tissues and spore-based reproduction illustrate a resilient basal lineage capable of thriving in diverse ecological contexts. Recent studies highlight their notable presence in overlooked environments - such as ephemeral wetlands, urban forests, and periglacial regions - where they function as structural vectors of biodiversity, microenvironmental sentinels, and support systems for specialized microfauna like nematodes and tardigrades. These findings underscore their role as models of evolutionary stability and strategic tools for ecological monitoring and the restoration of degraded landscapes.