Xenoxylon junggarensis sp nov., a new gymnospermous fossil wood from the Norian (Triassic) Huangshanjie Formation in northwestern China, and its palaeoclimatic implications
Xenoxylon junggarensis sp nov., a new gymnospermous fossil wood from the Norian (Triassic) Huangshanjie Formation in northwestern China, and its palaeoclimatic implications
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Xenoxylon junggarensis sp。
DOI：
10.1016/j.palaeo.2015.10.021
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发表时间：
2016
影响因子：
3
通讯作者：
Jun Wang
中科院分区：
文献类型：
--
作者：
Ming-Li Wan;Wei-Ming Zhou;Peng Tang;Lu-Jun Liu;Jun Wang
一种过矿化裸子植物木材，非洲木，Xenoxylon junggarensissp.十一月，新疆吉木萨尔县大龙口剖面诺利期（上三叠统）黄山街组中发现了一个新的化石。密木由厚壁管胞和薄壁射线组成。其特征是通常圆形到非常压缩，连续或有时分开单列，偶尔圆形和交替双列放射状凹坑和一个或两个简单的大凹坑在每个交叉领域。化石木属XenonGothan被认为是中生代北半球较冷和/或较湿气候的指示。该化石产于准噶尔盆地黄山街组，结合古植物和孢粉资料，表明诺利期北方新疆地区气候温暖湿润。22个年轮分析的平均灵敏度为0.36，表明对气候的季节性反应。化石木的生长轮很大（平均2.3毫米，最大5.44毫米），代表着更长的生长季节或更有利的生长条件，包括容易获得的水和更高的温度。根据大量的早材和少量的晚材以及一些间接证据，推测黄杨木的生长与晚材的生长有关。晚三叠世高纬度准噶尔盆地的准噶尔盆地活动受光照水平的限制。
A permineralized gymnospermous wood,Xenoxylon junggarensissp. nov., is described from the Norian (upper Triassic) Huangshanjie Formation in Dalongkou Section, Jimsar County, Xinjiang Uygur Autonomous Region, northwestern China. The pycnoxylic wood consists of thick-walled tracheids and thin-walled rays. It is characterized by commonly rounded to very compressed, contiguous or sometimes separated uniseriate, occasionally rounded and alternate biseriate radial pits and one or two simple, large pits in each cross-field.. The fossil wood genusXenoxylonGothan is known to be an indicator of cooler and/or wetter climates in the boreal hemisphere during the Mesozoic. Its occurrence in the Huangshanjie Formation from Junggar Basin, together with the palaeobotanical and palynological data, indicates that a wet and temperate climate prevailed in the northern Xinjiang during the Norian interval. The mean sensitivity of analysis of 22 growth rings is 0.36, suggesting a seasonal response to climate. Growth rings in the fossil woods are large (2.3 mm average with a maximum of 5.44 mm), representing either a longer growing season or more favorable conditions for growth, including readily available water and higher temperature. Based on a considerable amount of earlywood and a small percentage of latewood and some indirect evidence, it is hypothesized that growth ofX. junggarensisin the high-latitude Junggar Basin in the late Triassic was limited by light levels.