Portuguese historical palaeobotanical collections reveal a new species of late Palaeozoic marattialean fern

A new Late Pennsylvanian marattialean species, Cyathocarpus felicianoi sp. nov., is described and illustrated from the Douro Carboniferous Basin, northwestern Portugal, from Stephanian C (upper Gzhelian, Upper Pennsylvanian) deposits. The studied fossil material is composed of penultimate and ultimate sterile ‘pecopterid’ frond fragments preserved as adpressions and belongs to the Carlos Teixeira's collection, an invaluable palaeobotanical collection from the Portuguese geological surveys. The description of this new fern fossil-species based on historical palaeobotanical collections, highlights the importance of natural history collections for the advancement of science, especially regarding the knowledge about diversity and richness of marattialean ferns of Euramerican Carboniferous. • A new species of the extinct marattialean fern fossil-genus Cyathocarpus is described from the Douro Carboniferous Basin (Upper Pennsylvanian; Portugal). • The new Cyathocarpus species is erected based on an adpression fossil housed in the Carlos Teixeira's collection, an invaluable palaeobotanical collection from the Portuguese Geological Surveys. • Cyathocarpus felicianoi sp. nov. shows broadly lingulate pinnules with slightly crenulate margins, and generally simple and very-spaced veins. • New discoveries based on historical palaeontological collections, highlights the importance of natural history collections for the advancement of science.