New findings of the female reproductive structures of Nagrenia Nosova (Ginkgoales) and the seeds of Ginkgo gomolitzkyana Nosova from the Middle Jurassic of Angren, Uzbekistan

Abstract

New findings of the female reproductive structures of Nagrenia (Ginkgoales) and the seeds of Ginkgo gomolitzkyana are reported from the Middle Jurassic Angren Formation (Angren, Uzbekistan). The investigation reveals the presence of hairs and papillae on the outer epidermis in the seeds of G. gomolitzkyana. An emended diagnosis for G. gomolitzkyana is given. The only species formally described so far is Nagrenia samylinae, also from the Angren Formation. Two new species, N. pilosa and N. leviana, are erected based on morphological and epidermal features. Reproductive structures of N. pilosa differ from the type species in having hairs and hollow papillae on the collar surface. Seeds of G. gomolitzkyana and reproductive structures of N. pilosa share a similar epidermal pattern and thus likely represent parts of the same plant. Unlike N. samylinae and N. pilosa, structures of N. leviana have a longer plicate pedicel, the inner surface of these collars is completely preserved with a conical protrusion in the center.