A new araucarian pollen cone with in situ Cyclusphaera Elsik from the Aptian of Patagonia, Argentina
A new araucarian pollen cone with in situ Cyclusphaera Elsik from the Aptian of Patagonia, Argentina
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DOI：
10.1016/j.cretres.2005.04.005
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发表时间：
2005-10-01
影响因子：
2.1
通讯作者：
Archangelsky, S
中科院分区：
文献类型：
--
作者：
Del Fueyo, GM;Archangelsky, S
描述了采自阿根廷圣克鲁斯省阿普梯阶Anfiteatro de Tico组（Baquero群）的一种新的南洋杉花粉锥Alkastrobuspeltatus gen.etsp.nov.。雄球花多为扁平状，其小孢子囊中含有著名的Cyclusphaera Elsik花粉。在光学显微镜、扫描电镜和透射电镜下观察了沿着花粉粒分布的雄球花的形态、解剖和超微结构。根据小孢子叶解剖学和形态学，以及与其他南洋杉花粉粒的比较，建立了与南洋杉科的亲缘关系。在白垩纪的巴塔哥尼亚，产生Araucariacites、Balmeiopsis和Cyclusphaera花粉的植物生活在一起。所有三种类型的花粉都存在于小孢子囊内。Araucariacites是现存的Araucaria和Agathis属中唯一存活至今的类型。这个新属证实了南洋杉科在冈瓦纳西部早白垩世时期所获得的广泛多样性。(C)2005爱思唯尔有限公司保留所有权利。
A new araucarian pollen cone Alkastrobus peltatus gen. et sp. nov. is described from the Anfiteatro de Tico Formation (Baquero Group) of Aptian age ill Santa Cruz province, Argentina. The pollen cones are mostly compressions and their microsporangia contain the well-known Cyclusphaera Elsik pollen. The morphology, anatomy and ultrastructure of the pollen cones along with the pollen grains were examined under light, scanning and transmission electron microscopy. An affinity with the Araucariaccae is established on the basis of microsporophyll anatomy and morphology, and comparison of Cyclusphaera with other araucarian pollen grains. In Patagonia during the Cretaceous Period, plants producing Araucariacites, Balmeiopsis and Cyclusphaera pollen lived together. All three types of pollen are found inside microsporangia. Araucariacites, the only type that has survived to the present day, is found in the extant genera Araucaria and Agathis. The new genus confirms the broad diversity that Araucariaccae attained during the Early Cretaceous within western Gondwana. (C) 2005 Elsevier Ltd. All rights reserved.