New species of Zamites from the Cenomanian of the Bohemian Cretaceous Basin

Abstract

Zamites pateri J.Kvaček is described as a new member of the Bennettitales from the Cenomanian of the Peruc-Korycany Formation, Bohemian Cretaceous Basin in the Czech Republic. It comes from fluvial sediments exposed in the Pecínov quarry. It is compared to Zamites bayeri J.Kvaček from the Peruc-Korycany Formation, from which it differs in having pinnae attached to the dorsal part of the rachis and in cuticular details, particularly in having costal zones narrower than intercostal zones, stomata orientated always perpendicularly to the leaf margins and a thinner adaxial cuticle. Epidermal characters, particularly sunken stomata and numerous papillae underpin the mesophytic/xerophytic nature of the plant fossil.

Stomatal development and orientation: a phylogenetic and ecophysiological perspective

“…4A–D ), typically associated with distinctive GC thickenings and undulating anticlinal walls on intercostal epidermal cells ( Florin, 1933 ; Sincock and Watson, 1988 ; Watson and Sincock, 1992 ; Rudall et al , 2013 ; Rudall and Bateman, 2019 ). For example, Zamites (Bennettitales) had compound leaves with strap-shaped pinnae bearing transverse stomata in axial cell files ( Kvaček, 2022 ). Stomatal orientation can vary from random to transverse across a single pinna in bennettite leaves ( Rudall and Bateman, 2019 ).…”