Selaginella in Cretaceous amber from Myanmar

Selaginella (Selaginellales, Selaginellaceae) is the most speciose genus of lycophytes and, with approximately 750 recognized present-day species, also one largest genera vascular plants. However, evolutionary history this species richness remains largely unresolved. Recent research suggests that was diverse already in mid-Cretaceous and shows S. subg. Stachygynandrum dates back at least to incipient Angiosperm Terrestrial Revolution some 100 million years ago. Here, we describe 20 new fossil-species based on fertile shoots spores preserved Kachin amber from Myanmar emend previously described cretacea. Ten (S. ciliifera, cretacea, grimaldii, heterosporangiata, longifimbriata, minutissima, ohlhoffiorum, patrickmuelleri, villosa, wangxinii) represent because they possess anisophyllous strobili. The other eleven have isophyllous Two them isophylla, wunderlichiana) are tentatively assigned Ericetorum, whereas others amplexicaulis, aurita, heinrichsii, konijnenburgiae, obscura, ovoidea, pellucida, tomescui, wangboi) cannot be placed into any fossil or extant subgenus. fossils study nearly duplicate documented record free-sporing plants amber. abundance diversity cryptogams, along absence xerophytes among taxa, suggestive constantly high humidity understory source forests Citation: Schmidt A. R., Korall P., Krings M., Weststrand S., Bergschneider L., Sadowski E.-M., Bechteler J., Rikkinen J. & Regalado L. 2022: Cretaceous Myanmar. – Willdenowia 52: 179–245. Version first published online 22 September 2022 ahead inclusion August issue.