Five independent contrasts were made of sister groups where one of the groups was associated with gymnospermous
plants and the other with angiosperms, all yielding a positive difference in favor of the hypothesis that feeding on angiosperms is associated with enhanced taxonomic diversity (Farrell, 1998).
Initially, he distinguished "scalariform tissues" interpreted as belonging to lycopsids from "discigenous wood-cells" interpreted as gymnospermous
(Dawson 1859, p.
Four main ecological sporomorph groups characterize the samples: (1) gymnospermous
inaperturates and saccates; (2) angiospermous monocotyledons and (3) dicotyledons; and (4) pteridophytic fern spores.
The facies context of the only well provenanced Artisophyton specimen indicates that it grew on a well drained, seasonally dry landscape dominated by fire-prone gymnospermous
vegetation (Falcon-Lang 2003).
2006), "The typical gymnospermous
seed coat comprises three layers: and outer fleshy parenchymatous layer (sarcotesta), a middle sclerenhymatous (stony) layer (sclerotesta) and an innermost parenchymatous layer (endotesta) which generally collapses at maturity and fonns a thin membranous layer".
Madagascar does not have any endemic gymnospermous