Florinanthus bussacensis sp. nov., a new cordaitalean cone from the Upper Pennsylvanian of Portugal

Abstract

A new species of adpression cordaitalean cone is described from the Stephanian C (Upper Pennsylvanian) Vale da Mó “Formation” of the Buçaco Carboniferous Basin, central western Portugal. The macro- and micro-morphology of the new species, named Florinanthus bussacensis sp. nov., is described and its ontogenetic and palaeoecological significance assessed. The new cone species is erected on the basis of three primary axes with secondary fertile shoots with fimbriate apices. The number, linear-filiform shape and small size of the structures preserved on the distal parts of the scales suggests they represent pollen sacs, thus the new species F. bussacensis is considered to represent a male fructification. The new species is characterized by pollen sacs grouped in 4 to 5 clusters, composed of 4–7 basally fused sacs, and ovate to lanceolate-shaped sterile scales. The new cone seems to present different maturation states (mature to overmature) of its shoots, and its association with Cordaites leaves and Carpolites and Cardiocarpus seeds/ovules, suggests the new species was probably produced by the same parent plant species. The morphological and taxonomic diversity of the Pennsylvanian Cordaitaceae fructifications in western Variscan Euramerica remains largely unclear, due to the difficult recognition of these structures in the fossil record. This is the second record of a cordaitalean cone in the Carboniferous of Portugal, despite the abundance of cordaitalean remains (mainly of leaves, seeds, stems and roots) in its sequences. The difficult recognition of these structures in poor preservation conditions can easily make them go unnoticed and is more likely to be this the cause of their poor knowledge than a hypothetical limited record.