Ginkgoalean woods from the Jurassic of Argentina: Taxonomic considerations and palaeogeographical distribution
Ginkgoalean woods from the Jurassic of Argentina: Taxonomic considerations and palaeogeographical distribution
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DOI：
10.1016/j.geobios.2011.01.007
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发表时间：
2012-03-01
期刊：
影响因子：
1.6
通讯作者：
Gnaedinger, Silvia
中科院分区：
文献类型：
--
作者：
Gnaedinger, Silvia
详细描述了阿根廷圣克鲁斯省早侏罗世罗卡布兰卡组（Roca Blanca Formation）的一个新种Baieroxylon rocablanquense nov. sp.和中侏罗世拉马蒂尔德组（La Matilde Formation）的一个新种Ginkgomyeloxylon tanzanii Giraud和Hankel。形态属Baieroxylon的鉴定是基于次生木质部特征（横场管胞纹孔、横场和射线特征），而银杏髓木的鉴定是基于髓、初生木质部和次生木质部特征。Ginkgoalean木材的合成，结合诊断解剖证据与数据有关的地层和古地理分布。在此基础上，提出了一个属级鉴定检索表，并提出了一个新属-银杏属。这些结果被用来阐明全球的历史分布在地质时间的过程中的模式。在冈瓦纳大陆，中生代，特别是晚三叠世，出现了多种多样的“混合型”森林。相比之下，在劳亚大陆的混合型的多样性较低的记录为古生代和中生代，增加了“松香型”木材-类似于现存的银杏-发生在白垩纪初。在侏罗纪和早白垩世，在劳亚大陆和冈瓦纳大陆，混合型和冷杉型木材共存，说明木材解剖学的重要演变发生在中生代（侏罗纪-白垩纪）。(c)2011年Elsevier Masson SAS。All rights reserved.
A specimen of Baieroxylon rocablanquense nov. sp. from the Roca Blanca Formation (Early Jurassic), and a specimen of Ginkgomyeloxylon tanzanii Giraud and Hankel from the La Matilde Formation (Middle Jurassic), both located in the Santa Cruz province, Argentina, are described in detail. Identification of the morphogenus Baieroxylon is based upon secondary xylem characteristics (cross-field tracheid pitting, cross-fields and ray characters), while identification of Ginkgomyeloxylon is based upon pith, primary xylem and secondary xylem features. A synthesis of Ginkgoalean woods is presented, which combines diagnostic anatomical evidence with data related to stratigraphic and paleogeographical distributions. Based on the results of this analysis, a key for genus-level identification is provided and a new genus, Ginkgopitys, is proposed. These results are used to elucidate global patterns of historical distribution over the course of geological time. In Gondwana, a great diversity of "mixed-type" woods was present during the Mesozoic, especially during the Late Triassic. In contrast, in Laurasia a lower diversity of the mixed-type is recorded for the Paleozoic and Mesozoic, with increases in "abietinoid-type" wood - similar to extant Ginkgo - taking place at the beginning of the Cretaceous. During the Jurassic and Early Cretaceous in both Laurasia and Gondwana, mixed-type and abietinoid-type woods co-existed, illustrating that important evolutionary changes in wood anatomy occurred during the Mesozoic (Jurassic-Cretaceous). (c) 2011 Elsevier Masson SAS. All rights reserved.