Adpression of medullosan prepollen-producing organs, their prepollen and cuticles (Westphalian, Intrasudetic Basin, Czech Republic)

Abstract

The adpression fossil record from the Westphalian of the Intrasudetic Basin (Czech Republic) contains diversified medullosan prepollen organs. Langsettian bell-shaped prepollen organs were found in the Lampertice Member in the Žacléř area: Whittleseya elegans Newberry, W. delphinae Stockmans et Willière, W. silesiaca Pacyna et Zdebska and Givesia media (Stockmans) Stockmans et Willière. These fructifications may have been produced by plants with fronds of the fossil-genera Neuralethopteris Cremer and Alethopteris Sternberg. Parent plants of small Langsettian Aulacotheca sp. are uncertain. Duckmantian medullosan male fructifications from the Malé Svatoňovice area are elongated capsules described as Aulacotheca idae Šimůnek sp. nov. and were produced by plants with Alethopteris idae Šimůnek fronds. The prepollen grains and cuticles were isolated from Whittleseya elegans, W. delphinae, Givesia media and Aulacotheca idae. All prepollen grains are oval with two longitudinal grooves and a monolete suture, and are classified as Monoletes ovatus Schopf. There is great overlap in the dimensions of the prepollen of Whittleseya elegans, W. delphinae and Givesia media – 155–230 μm long and 100–180 μm wide. Prepollen of Aulacotheca idae are much bigger – 330–375 μm long and 190–245 μm wide. The inner cuticular layer is gently cutinised with polygonal cells. Cuticles from the prepollen organ surface has elongated cells in Whittleseya elegans (with stomata) and Givesia media (with trichome bases), and has polygonal cells in Whittleseya delphinae (with periclinal cell wall thickenings) and Aulacotheca idae (with hollow papillae on periclinal cell walls). The question, as to whether Whittleseya elegans and W. delphinae are conspecific is discussed.