On a new species of the calamitalean fossil-genus Annularia from the Douro Basin (lower Gzhelian; NW Portugal)

ABSTRACT

This paper deals with a new species of the calamitalean fossil-genus Annularia von Sternberg, Annularia noronhai sp. nov., from the Douro Basin (lower Stephanian C/lower Gzhelian, Upper Pennsylvanian), in north-western Portugal. A. noronhai sp. nov. is distinguished mainly by its lanceolate leaves with acuminate to caudate apices, which are characterised by having a very elongate mucro. Among the known species of Annularia, Annularia spinulosa is the most similar. In this study, we also reassess the taxonomic status of A. spinulosa based on comparisons between its type specimen (holotype) and specimens from Douro Basin described to this fossil-species.

KEYWORDS:

• Annularia
• Calamitaceae
• Equisetales
• Douro Basin
• lower Gzhelian
• Portugal

Acknowledgments

The authors thank to Mihai Popa (University of Bucharest, Faculty of Geology and Geophysics, Laboratory of Paleontology, Bucharest, Romania) and to one anonymous reviewer for their constructive comments on the submitted manuscript. We also thank to the National Museum of Prague (M. Libertín, Czech Republic) for access permission to the holotype material of Annularia spinulosa illustrated in this study. This study was financially supported by Fundação Calouste Gulbenkian and by Fundação da Ciência e Tecnologia (QREN-POPH-Type 4.1-Advanced Training, subsidised by the European Social Fund and national funds MCTES) through a Ph.D. scholarship (SFRH/BD/78741/2011) granted to P. Correia.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Fundação Calouste Gulbenkian;Fundação da Ciência e Tecnologia (QREN-POPH-Type 4.1-Advanced Training, with subsidies from the European Social Fund and MCTES national funds) through by a Ph.D. scholarship (SFRH/BD/78741/2011).