New interpretation of seeds Grenana Samylina (Gymnospermae) from the Middle Jurassic of Angren, Uzbekistan

Abstract

The seeds described by Samylina (1990) from the Middle Jurassic of Angren (Uzbekistan) as Grenana angrenica are revised. Samylina also described under this name the ovuliferous organs and leaves found in the same locality in association with these seeds, selected a leaf specimen as a holotype, and interpreted G. angrenica as a peculiar seed fern. The revision shows that the seeds exhibit structure characteristic of the Ginkgoales. The seeds, leaves, and ovuliferous organs were not found in organic connection with one another. Therefore, they cannot be described under the same name, despite the considerable similarity in epidermal-cuticular features. The dispersed seeds of ginkgoalean affinity are usually attributed to the genus Allicospermum Harris. On the basis of reexamination of the Angren material, a new species, Allicospermum budantsevii sp. nov., is described.