New evidence of the reproductive organs of Glossopteris based on permineralized fossils from Queensland, Australia: II. Pollen-bearing organ Ediea gen. nov
Nishida, H. ((Chuo University, Bunkyo-ku, Tokyo (Japan). Department of Biological Sciences, Faculty of Science and Engineering), (University of Tokyo, Tokyo (Japan). Graduate School of Science)) | Pigg, K.B. | Kudo, K. | Rigby, J.F.
Ediea homevalensis H. Nishida, Kudo, Pigg and Rigby gen. et sp. nov. is proposed for permineralized pollen-bearing structures from the Late Permian Homevale Station locality of the Bowen Basin, Queensland, Australia. The taxon represents unisexual fertile shoots bearing helically arranged leaves on a central axis. The more apical leaves are fertile microsporophylls bearing a pair of multibranched stalks on their adaxial surfaces that each supports a cluster of terminally borne pollen sacs. Proximal to the fertile leaves there are several rows of sterile scale-like leaves. The pollen sacs (microsporangia) have thickened and dark, striate walls that are typical of the Arberiella type found in most pollen organs presumed to be of glossopterid affinity. An examination of pollen organs at several developmental stages, including those containing in situ pollen of the Protohaploxypinus type, provides the basis for a detailed analysis of these types of structures, which bear similarities to both compression/impression Eretmonia-type glossopterid microsporangiate organs and permineralized Eretmonia macloughlinii from Antarctica. These fossils demonstrate that at least some Late Permian pollen organs were simple microsporophyll-bearing shoot systems and not borne directly on Glossopteris leaves.
Показать больше [+] Меньше [-]