|
|
||||||||
Paleobotany |
í Kva
ek2,5
ina Da
ková42National Museum, Prague, Václavské nám. 68, 115 79 Praha 1, Czech Republic; 3Department of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK; 4Academy of Sciences, Rozvojová 135, 165 00 Praha 6, Lysolaje, Czech Republic
During the Mesozoic Era, gingkoaleans comprised a diverse and widespread group. Here we describe ginkgoalean fossils in their facies context from the Late Cretaceous (Cenomanian) Peruc-Korycany Formation of the Czech Republic and present a reconstruction of tree architecture and ecology. Newly described in this study is the ovuliferous reproductive structure, Nehvizdyella bipartita gen. et sp. nov. (Ginkgoales). This ovuliferous organ consists of a bifurcating axis, terminated by large cupule-like structures, probably homologous to the collar of the recent Ginkgo. Each cupule encloses an orthotropous ovule. In specimens with the early developmental stages preserved, the entire ovule and young seed, with the exception of the micropylar area, is embedded in the cupule. Mature seeds consist of sclerotesta and sarcotesta. Monosulcate pollen grains of Cycadopites-type are found adhering to the seeds. Although similar to Ginkgo in terms of its large size and reduced number of seeds, N. bipartita differs from the extant genus in having ovules completely enclosed in a cupule-like structure. The co-occurrence of N. bipartita with ginkgoalean leaves of Eretmophyllum obtusum (Velenovsk
) Kva
ek, J., ginkgoalean short shoots of Pecinovicladus kvacekii Falcon-Lang, and ginkgoalean trunk wood of Ginkgoxylon gruettii Pons and Vozenin-Serra in monodominant taphocoenoses at four geographically distant localities suggests that these remains all belong to one plant. This is supported by the close morphological and anatomical similarity between the different organs. Facies analysis of plant assemblages indicates that our Cretaceous tree occupied a water-stressed coastal salt marsh environment. It therefore represents the first unequivocal halophyte among the Ginkgoales.
Key Words: Cenomanian Cycadopites Eretmophyllum Ginkgoales Ginkgoxylon Late Cretaceous Nehvizdyella Pecinovicladus
This article has been cited by other articles:
![]() |
C. Coiffard, B. Gomez, and F. Thevenard Early Cretaceous Angiosperm Invasion of Western Europe and Major Environmental Changes Ann. Bot., September 1, 2007; 100(3): 545 - 553. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |