RESEARCH ARTICLE Douropteris alvarezii gen. nov., sp. nov., a new medullosalean pteridosperm from the Late Pennsylvanian of Portugal Pedro Correia 1,5 | Zbynĕk Šimůnek 2 | Christopher J. Cleal 3 | Artur A. Sá 4,5 1 Institute of Earth Sciences of University of Porto, Porto, Portugal 2 Czech Geological Survey, Prague, Czech Republic 3 Department of Natural Sciences, National Museum Wales, Cardiff, UK 4 Department of Geology, University of Trás‐os‐Montes e Alto Douro, Vila Real, Portugal 5 Geosciences Centre, University of Coimbra, Coimbra, Portugal Correspondence P. Correia, Institute of Earth Sciences, Pole of the Faculty of Sciences, University of Porto, Rua do Campo Alegre, 687, 4169‐007 Porto, Portugal. Email: pedro.correia@fc.up.pt Funding information Fundação da Ciência e Tecnologia, Grant/ Award Number: SFRH/BD/78741/2011; Fundação Calouste Gulbenkian; National Museum Wales Research Program, Grant/ Award Number: NS49; Czech Geological Sur- vey, Grant/Award Number: CGS 323100 Handling Editor: Ian D. Somerville A new plant fossil‐genus, Douropteris alvarezii gen. nov., sp. nov., is described from the Douro Basin (lower Stephanian C [lower Gzhelian], Upper Pennsylvanian) in north‐ western Portugal. Douropteris alvarezii has a remarkable morphology characterized by an unusual combination of features seen in several different fossil‐genera belong- ing to ferns and pteridosperms. Its unique and distinguishing features place it nearest to the medullosalean pteridosperms Margaritopteris and Callipteridium, suggesting close affinities with the fossil‐family Cyclopteridaceae. Morphologically, Margaritopteris is the closest relative with basis on the strong resemblance to the veining pattern of Douropteris gen. nov. Here, Douropteris represents a potential “Lazarus taxon” or evolutionary descendant from the Margaritopteris lineage. KEYWORDS Douro Basin, Douropteris alvarezii gen. nov., Late Pennsylvanian, Medullosales, Portugal, pteridosperm, sp. nov. 1 | INTRODUCTION The medullosalean pteridosperms (Medullosales) are a group of extinct seed‐bearing plants characterized by fern‐like foliage that flourished widely in tropical habitats of Euramerica and China during the late Carboniferous to early Permian (e.g., Cleal, 2008; Cleal & Popa, 2015; Cleal & Shute, 2003, 2012; Mapes & Rothwell, 1980; Seyfullah, Hilton, Wang, & Galtier, 2009; Taylor & Eggert, 1967). They occupied mainly wetland habitats but during the Moscovian occurred more abundantly in better drained clastic substrate habitats (Cleal, 2008). These habitats generally were located in lowland and upland intramontane basins (e.g., Cleal, 2008; Cleal & Popa, 2015; Šimůnek & Cleal, 2004). The first medullosalean forms appeared dur- ing the late Mississippian (Cleal & Shute, 2012; Dunn et al., 2003; Laveine, Lemoigne, & Shanzhen, 1993; Mapes & Rothwell, 1980; Taylor & Eggert, 1967), but they were especially abundant and diverse in Westphalian and Stephanian times (Cleal & Shute, 2012). The last representatives of the medullosalean pteridosperms became extinct in Euramerica and China (Amerosinian Realm) in the Asselian (early Permian; Cleal & Shute, 2012; Rößler et al., 2012; Seyfullah et al., 2009). Most medullosalean taxa were monoaxial shrubs and small trees (e.g., Cleal & Shute, 2012; Retallack & Dilcher, 1988; Wnuk & Pfefferkorn, 1984), with fronds that ranged in length from 1 to 7 m (e.g., Cleal & Shute, 1991; Cleal & Shute, 2012; Laveine, 1986; Laveine & Belhis, 2007), although some Stephanian–early Permian taxa (e.g., Lescuropteris Schimper and Odontopteris [Brongniart] Sternberg) have developed a scrambling/climbing or lianescent growth habit (described as vine‐ and liana‐like pterido- sperms), with axillary branches arising from the stems and having non‐arborescent forms with small fronds usually less than 0.5 m (Cleal & Shute, 2012; Hamer & Rothwell, 1988; Krings et al., 2006; Krings & Kerp, 1997; Krings, Kerp, Taylor, & Taylor, 2003). The medullosaleans generally produced large ovules and had complex pol- len‐organs, consisting of elongate pollen sacs (sporangial tubes) arranged in a ring or aggregated into concentric rings (e.g., Anderson, Anderson, & Cleal, 2007; Beck & Wight, 1988; Cleal, 2008). Received: 8 December 2017 Revised: 4 May 2018 Accepted: 5 May 2018 DOI: 10.1002/gj.3251 Geological Journal. 2018;1–11. Copyright © 2018 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/gj 1