Leaf Cuticle Anatomy and the Ultrastructure ofGinkgoites ticoensisArchang. from the Aptian of Patagonia

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. The leaf cuticle of the Ginkgoites ticoensis Archang. type material from the Aptian Anfiteatro de Ticó Formation in Patagonia, Argentina, is fully characterized with additional scanning and transmission electron microscopic observations. Many new anatomical and ultrastructural cuticular features are identified in the four-lobed leaf of G. ticoensis: the leaf shows a hypostomatic and papillate laminae, straight and pitted anticlinal and granulate periclinal walls, actinocytic stomata with between five and seven papillate, striate subsidiary cells, and guard cells with anticlinal smooth walls. The TEM studies on ordinary epidermal cells, papillae, subsidiary cells, and guard cells reveal general ultrastructural features of Ginkgoaceae: an outer polylamellate layer A made with A1 and a granular inner layer A2; A1 with an upper part A1U with continuous and straight translucent lamellae; a lower part A1L with significantly disrupted and waving translucent lamellae; and the fibrillar cuticular layer B1 as the innermost part. Ten ultrastructural characters are detailed and ranked by the use of confidence intervals based on 30 statistical measurements. A threedimensional reconstruction of the cuticle is also provided. Because of the anatomical and ultrastructural fine details shown in the G. ticoensis cuticle, new elements are given to suggest its probable family affinity and to enhance the specificities of Ginkgo and Ginkgoites.

Method for ultrastructural fine details of plant cuticles by transmission electron microscopy

“…The method allows, for fossil plants belonging to very various taxa observed until now (Coniferales, Ginkgoales, Czekanowskiales, Pteridosperrmales, Cycadales…) and from various geological periods [ [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] – 18 , [21] , [22] , [23] , [24] , [25] , [26] , [27] – 28 ], also for living plants as angiosperms and gymnosperms [ 19 , 20 ], a very satisfying observation of the cuticles through transmission electron microscope. These sections are very flat (the efficient infiltration of resin makes no disruption between cuticle and Epon resin, mainly thanks to the long embedding procedure of one week), high numbers of sections can be obtained as a routine, over a few hundreds for some taxa, enabling statistical measurements.…”

“…Very homogeneous granules of B2 layer, lowermost part of the cuticle; Pseudofrenelopsis gansuensis (Coniferales, Cheirolepidiaceae), Mesozoic (Lower Cretaceous), OEC. For other photos of these cuticle taxa, see [21] for Gingkoites ticoensis) , Guignard et al. [25] for Pseudofrenelopsis gansuensis, Carrizo et al.…”

Cuticle ultrastructure in Brachyphyllum garciarum sp. nov (Lower Cretaceous, Argentina) reveals its araucarian affinity

“…In Brachyphyllum garciarum sp. nov. ultrastructure features are not identical to those present in other fossil families and orders such as: other Coniferales (Cheirolepidiaceae, Guignard et al, 1998, Yang et al, 2009, Guignard et al, 2017, Yang et al, 2018fossil Miroviaceae, Nosova et al, 2016; living Pinaceae, Bartiromo et al, 2012); Ginkgoales (Baiera-Sphenobaiera cuticle group of Ginkgoales above mentioned; Wang et al, 2005; Ginkgo-Ginkgoites-Pseudotorellia group; Guignard and Zhou, 2005;Del Fueyo et al, 2006, Del Fueyo et al, 2013Guignard et al, 2016, Nosova et al, 2019; Czekanowskiales (Zhou and Guignard, 1998); Pteridospermales (Guignard et al, 2001;Thévenard et al, 2005;Carrizo et al, 2014) including Corystospermaceae (Guignard et al, 2004); Bennettitales (Villar de Seoane, 1999Seoane, , 2001Seoane, , 2003; cycadalean cuticles (Archangelsky et al, 1995;Artabe et al, 1991;Passalia et al, 2010).…”

Ginkgoites patagonica(Berry) comb. nov. from the Eocene of Patagonia, Last Ginkgoalean Record in South America

“…Interestingly, they were never the dominant component in any plant community (Del Fueyo et al 2013).…”

“…Their origin has been associated with Permian families such as the Trichopytiaceae and the Dicranophyllaceae, from which true ginkgoaleans are thought to have evolved during the Mesozoic (Archangelsky and Cúneo 1990;Stewart and Rothwell 1993;Villar de Seoane 1997;Del Fueyo and Archangelsky 2001;Crane 2013;Del Fueyo et al 2013).…”