Ultrastructure of the "cuticular membrane" in two Late Triassic corystospermaceous taxa from India

Abstract

Ultrastructure of the cuticular membrane in two types of corystospermaceous pinnae, referred to Dicroidium gouldii (= D. corlaceum sensu Pal 1984) and Dicroidium sp. (= D. zuben sensu Pal 1984) has been studied. It is observed that while the epidermal pattern in the two species shows only minor variation, at the ultrastructure level the cuticular membranes of the two species show significant differences.

New dimensions in palaeobotanical research: ultrastructural studies on plant fossils

“…Cuticle ultrastructure may also be used as a taxonomic feature as the fossil cuticles are the most widespread unaltered plant remains that retain morphology (cellular pattern) diagnostic for the taxon (Maheshwari & Bajpai, 1996b). For example, Cheirolepidiaceae, a family of Mesozoic fossil conifers, considered to be (i) transitional between Voltziales and Taxodiaceae (Jung, 1968), or (ii) related to Araucariaceae on the basis of organisation of the ovule-producing organ (Krassilov, 1982) or (iii) related to Araucariaceae and Taxodiaceae on the basis of organisation of the foliar stomata (Clement-Westerhof & van Konijnenburg-van Cittert, 1991), has been found to show close similarity in cuticle ultrastructure to that in Taxodiaceae (de Seoane, 1998).…”

“…In the inner zone the fibrillae acquire a "herring bone" pattern, a stress character. x 62,000 (from Maheshwari & Bajpai, 1996b). 6.…”

“…Uninfected cuticular membrane of Thinfeldia indica showing amorphous nature. x 22,000 (from Maheshwari & Bajpai, 1996b). -< a::l examine the preservation of the particulate organic matter and palynofossils to understand the depositional environment of sediments.…”