A new Late Cretaceous ginkgoalean reproductive structure Nehvizdyella gen. nov from the Czech Republic and its whole-plant reconstruction
A new Late Cretaceous ginkgoalean reproductive structure Nehvizdyella gen. nov from the Czech Republic and its whole-plant reconstruction
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DOI：
10.3732/ajb.92.12.1958
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发表时间：
2005-12-01
影响因子：
3
通讯作者：
Dasková, J
中科院分区：
文献类型：
--
作者：
Kvacek, J;Falcon-Lang, HJ;Dasková, J
在中生代，银杏树是一个广泛分布的多样性群体。在这里，我们描述了ginkgoalean化石在其相背景下，从晚白垩世（Cenomanian）秘鲁Korycany形成的捷克共和国，并提出了重建的树木结构和生态。本文报道了银杏目（Ginkgoales）银杏属（Nehvilzdyella bipartita gen. et sp. nov.）这胚珠器官包括一个分叉轴，终止于大杯状结构，可能同源于最近银杏的衣领。每个壳斗内藏一个直生胚珠。在早期发育阶段保存的标本中，整个胚珠和年轻的种子，除了珠孔区域，都嵌入壳斗中。成熟种子由种皮和肉种皮组成。发现苏铁类的单槽花粉粒粘附在种子上。虽然与银杏相似，在其大的尺寸和减少的种子数量方面，N。bipartita与现存属的不同之处在于胚珠完全包被在杯状结构中。N. bipartita与Eretmophyllum obtusum（Velenovsky）Kvacek，J.，Pecinovicladus kvacekii Falcon-Lang的银杏短枝和Ginkgoxylon gruettii脑桥和Vozenin-Serra的银杏树干木材在四个地理上遥远的地点的单优势的taphocoenoses表明，这些遗骸都属于一种植物。这是由不同器官之间的密切形态和解剖相似性支持的。植物组合的相分析表明，我们的白垩纪树木占据了水分胁迫沿海盐沼环境。因此，它代表了银杏目中第一个明确的盐生植物。
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, Nehvilzdyella 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 (Velenovsky) Kvacek, 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.