First record of Cyathocarpus (Marattiales) in Gondwana: A new species from the Permian of Patagonia, Argentina

Abstract

Marattialean ferns were key components of Paleozoic wetland ecosystems, yet their biogeographic history in Gondwana remains poorly resolved. While Cyathocarpus is well documented from Euramerica and Cathaysia, no species had been recognized in Gondwana—until now. We describe Cyathocarpus polinensis sp. nov. from the Guadalupian La Golondrina Formation of Patagonia, Argentina, representing the first Gondwanan record of the genus. The species exhibits a distinctive arrangement of synangial rows that do not contact the midvein or pinnule margins and are consistently absent from the apical and basal regions of the pinnules. The midvein is conspicuous, straight, and divides fanwise near the apex; lateral veins bifurcate once, close to the midvein. This discovery extends the paleogeographic range of Cyathocarpus and supports a dispersal scenario from Euramerica into southern Gondwana during the Cisuralian. These findings call for a critical reassessment of comparable Gondwanan taxa and underscore the role of southwestern Gondwana as a refugium and center of marattialean diversification during postglacial climatic recovery.