LesleyaLesquereux from the Pennsylvanian of the Iberian Massif: part of a dryland megaflora from the Variscan orogen, northwestern Portugal

Abstract

The Carboniferous – early Permian plant genus Lesleya is a characteristic component of “dryland floras” that occupied a wide range of moisture-stressed, well-drained environments in tropical regions of Euramerica. Fossil records of Lesleya are almost exclusively found in basinal lowlands. For example, occurrences in Early Pennsylvanian-age, seasonally dry, parautochthonous deposits in basinal lowlands of North America (e.g., Illinois Basin, USA) indicate that Lesleya lived in that region in low-altitude (lowland) paleoenvironments during dry climatic intervals. In this paper, we document the first occurrence of Lesleya during the Carboniferous on the Iberian Massif, in lower Gzhelian (Upper Pennsylvanian) strata of the Douro Carboniferous Basin, in northwestern Portugal. This newly discovered occurrence includes a new species, Lesleya iberiensis sp. nov., recognized on the basis of natural molds of leaves. The Portuguese Lesleya fossils are from upland intramontane deposits and occur between coal beds. Their fossil remains are preserved in mica-rich shales that were deposited between sandstone-dominated fluvial and shale-dominated lacustrine deposits, suggesting that this megaflora was deposited near freshwater bodies. These new data provide evidence that this megaflora grew in mountain riparian environments within the Variscan orogen, either in localized, well-drained areas or during drier climatic intervals in the Late Pennsylvanian.

Douropteris alvareziigen. nov., sp. nov., a new medullosalean pteridosperm from the Late Pennsylvanian of Portugal

“…The Douro Basin (Figure ) occurs within the Douro‐Beira Carboniferous Trough (DBCT) which is located within the Central Iberian Zone in the Iberian Massif of NW Portugal (e.g., Pinto de Jesus, ; Wagner & Lemos de Sousa, ). The Douro Basin strata are early Gzhelian (early Stephanian C) in age and represent continental intramontane syntectonic deposits occurring within a narrow range, with a width of less than 1 km tectonically induced by compressive stress, and showing 85 km length NW–SE‐striking lineament extending from São Pedro Fins (E Porto) to Janarde (E Arouca; e.g., Correia et al, ; Correia, Murphy, Sá, Domingos, & Flores, ; Correia, Šimůnek, Sá, & Flores, ; Domingos et al, ; Eagar, ; Fernandes, Pinto de Jesus, Teixeira, & Lemos de Sousa, ; Lemos de Sousa & Wagner, , ; Lemos de Sousa & Wagner, , ; Pinto de Jesus, , ; Wagner, ; Wagner & Lemos de Sousa, , ). These deposits comprise alluvial fan debris which are characterized by flow‐dominated sediment at the base, passing upwards into lacustrine–palustrine facies, overlain by strata deposited in a braided multistory–multichannel fluvial system (Pinto de Jesus, , ).…”

“…The fossil flora of the Douro Basin occurs essentially in parautochthonous deposits which are preserved in an upland intramontane basin within the Variscan mountain range (Correia et al, ; Correia et al, ).…”

“…The fossil flora of the Douro Basin occurs essentially in parautochthonous deposits which are preserved in an upland intramontane basin within the Variscan mountain range (Correia et al, 2016;Correia et al, 2018). includes the classification using fossil-families for medullosalean fronds proposed by Cleal and Shute (2003).…”

“…Geological map showing detailed geology of the São Pedro da Cova area. Modified from Correia et al (, figure 1) [Colour figure can be viewed at wileyonlinelibrary.com]…”

A new Late Pennsylvanian floral assemblage from the Douro Basin, Portugal

“…Geological map showing detailed geology of the São Pedro da Cova area. Modified from Correia, Sá, Murphy, Šimůnek, and Flores (, figure 1). DBCT = Douro‐Beira Carboniferous Trough [Colour figure can be viewed at wileyonlinelibrary.com]…”