Revision and significance of the Westphalian (Middle Pennsylvanian) arborescent lycopsid Bergeria dilatata (Lindley & Hutton) Álvarez-Vázquez & Wagner

Abstract

Bergeria dilatata (Lindley & Hutton) Álvarez-Vázquez & Wagner, a Middle Pennsylvanian lycopsid, is redescribed based on type material from England as well as 586 specimens from the Peñarroya-Belmez-Espiel Coalfield, Córdoba province, southern Spain. The species is characterized by longer than broad, smooth leaf cushions showing false leaf scars, and the presence of perennial, long, entire, single-veined leaves. A complete synonymy is presented and 21new species (two of them with doubts), previously placed in 6 diff erent genera, have been synonymized. Associated Flemingites-type cones, determined as Flemingites russelianus, yielded in situ spores of the Lagenoisporites rugosus type and microspores of the Microspinosporites type.

The nomenclature of fossil‐taxa representing different preservational states:Lepidodendronas a case‐study

“…Álvarez‐Vázquez & Wagner (2014) and Álvarez‐Vázquez & al. (2018) separated similar stems of arborescent lycophytes but with leaves still spirally attached into another genus, Bergeria Presl (in Sternberg, 1838; defined as “lycopsid stems covered with spirally arranged, rhomboidal leaf cushions, longer than broad, contiguous or separated by narrow grooves, and without a differentiated leaf scar. Leaves linear‐lanceolate, entire, single‐veined”).…”

“…As Álvarez‐Vázquez & al. (2018) pointed out, although these stems lack abscission leaf scars, the leaves were often lost either taphonomically or during collecting (e.g., when the rock was split) leaving a linear mark near the top of the leaf cushion; this is what Chaloner (1967, 1986a,b) described as a false leaf scar. Four new combinations were proposed for species previously attributed to Lepidodendron : Bergeria dilatata (Lindl.…”

“…Álvarez‐Vázquez & al. (2018) (≡ Lepidodendron lycopodioides Sternb. [Sternberg, 1821]) and Bergeria wingfieldense (Hemingway ex B.A.Thomas & Seyfullah) Álvarez‐Vázquez & al.…”

The distribution of plant fossils and their palaeoecology inDuckmantian(Bashkirian, Lower Pennsylvanian) strata atBrymbo, North Wales, UK

“…Álvarez-Vásquez and Wagner (2014) and Álvarez-Vásquez, Bek, Knight, and Wagner (2018) Bergeria which to us does not seem logical. Álvarez-Vásquez and Wagner (2014) added the comment that "the shape and size of the leaf scar to be due to the position of the leaf with regard to the leaf cushion and to the kind of leaf base, which may be either narrow or more laterally extensive."…”

“…Álvarez‐Vásquez and Wagner () and Álvarez‐Vásquez, Bek, Knight, and Wagner () transferred all leafy stems of arborescent lycophytes to the genus Bergeria Presl in Sternberg, , defining it as “lycopsid stems covered with spirally arranged, rhomboidal leaf cushions, longer than broad, contiguous or separated by narrow grooves, and without a differentiated leaf scar. Leaves linear‐lanceolate, entire, single‐veined.” They argued that commonly encountered species such as L .…”