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1. chinaXiv:201812.00009 [pdf]

The posterior cranial portion of the earliest known Tetrapodomorph Tungsenia paradoxa and the early evolution of tetrapodomorph endocrania

LU Jing; YOUNG Gavin; HU Yu-Zhi; QIAO Tuo; ZHU Min
分类: 生物学 >> 生物学其他学科

Abstract Here the posterior cranial portion of the tetrapodomorph Tungsenia from the Lower Devonian (Pragian, ~409 million years ago) of Yunnan, southwest China, is reported for the first time. The pattern of posterior skull roof and the morphology of the otoccipital region of the neurocranium are described in detail, providing precious insight into the combination of cranial characters of the earliest known tetrapodomorph to date. The posterior cranium of Tungseniadisplays a mosaic of features previously linked either to basal dipnomorphs such as Youngolepis(e.g., the well-developed subjugular ridge, the strong adotic process, and the poorly developed fossa bridgei) or to typical tetrapodomorphs (e.g., the lateral dorsal aortae commenced from the median dorsal aorta postcranially). The independent ventral arcual plate is also found in the advanced tetrapodomorph Eusthenopteron. The new endocranial material of Tungsenia further fills in the morphological gap between Tetrapodomorpha (tetrapod lineage) and Dipnomorpha (lungfish lineage) and unveils the sequence of character acquisition during the initial diversification of the tetrapod lineage. The new phylogenetic analysis strongly supports the basalmost position of Tungsenia amongst the tetrapod lineage.

提交时间: 2018-12-04 来自合作期刊:《古脊椎动物学报》 点击量340下载量158 评论 0

2. chinaXiv:201812.00010 [pdf]

Discovery of Omeisaurus (Dinosauria: Sauropoda) in the Middle Jurassic Shaximiao Formation of Yunyang, Chongqing, China

TAN Chao; DAI Hui; HE Jian-Jun; ZHANG Feng; HU Xu-Feng; YU Hai-Dong; LI Ning; WEI Guang-Biao; PENG Guang-Zhao; YE Yong; ZHANG Qian-Nan; REN Xin-Xin; YOU Hai-Lu
分类: 生物学 >> 生物学其他学科

A cervical vertebra recovered from the Middle Jurassic Lower Member of the Shaximiao Formation in Town of Puan, Yunyang County, Chongqing is assigned to an species undeterminata of the sauropod dinosaur Omeisaurus based on morphological and comparative study. The centrum of this mid-cervical is much hollower than solider with extremely developed fossa/foramen complex and has a high ratio (5.05) of its anteroposterior length excluding the articular ball divided by the mean value of the posterior articular surface mediolateral width and dorsoventral height. Additional features of this cervical include central length about twice the total vertebral height, a prominent midline keel on the central ventral surface, deep and long cavities bounded by centroprezygapophyseal lamina/ intraprezygapophyseal lamina and centropostzygapophyseal lamina/intrapostzygapophyseal lamina, respectively, a coel on the dorsal half of the postzygapophyseal centrodiapophyseal fossa, long prone epipophysis extending beyond the postzygapophysis facet, anteroposteriorly length of the neural spine about half the length of the centrum, and concavities on the anterior one third lateral surface of the neural spine. Therefore, this discovery reveals new morphological information on Omeisaurus, and this Omeisaurus-bearing Puan dinosaur quarry represents the easternmost occurrence of this genus.

提交时间: 2018-12-04 来自合作期刊:《古脊椎动物学报》 点击量286下载量148 评论 0

3. chinaXiv:201810.00167 [pdf]

土体水分潜在蒸发确定方法研究进展

夏琼; 王旭; 窦顺; 付晓丹
分类: 生物学 >> 生物学其他学科

以相关领域关于土体蒸发模型研究成果为基础,结合岩土工程蒸发过程的特点,对确定土体潜在蒸发量方法的发展及现状进行介绍,并对每种理论模型的适用条件及参数的确定等进行分析。得出以下认识:(1)特定的地区、气候条件下,通过多种理论模型对比分析,确定相对合适的理论模型估算潜在蒸发量是必要的。(2)气象参数的区域性很明显,即使是具有相似气候特征的小区域,不同的气象站提供的气象资料反演的气象参数也不相同,故根据气象资料反演得到的气象参数要进行修正。(3)现有蒸发测量技术应用于岩土工程的蒸发测量中有待进一步深入研究发展。提出该课题在岩土工程领域今后的研究方向,包括土体稳定蒸发阶段蒸发机制、蒸发的滞后效应、夜间土体水分变化对蒸发的影响、通用蒸发模型的建立及实测蒸发量的尺度效应等。

提交时间: 2018-10-23 来自合作期刊:《干旱区地理》 点击量766下载量151 评论 0

4. chinaXiv:201808.00145 [pdf]

New progress on the correlation of Chinese terrestrial Permo-Triassic strata

LIU Jun
分类: 生物学 >> 生物学其他学科

This paper reviews recent works on the age of Chinese terrestrial Permo-Triassic strata, mainly based on the isotopic dating and the tetrapod correlation. For the application of U-Pb dating methods for the stage-level division of Permo-Triassic strata, the best method is the Thermal Ionization Mass Spectrometer (TIMS), while the Secondary Ion Mass Spectroscopy (SIMS) can be used for many cases; however, the most popular Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS), which has nearly 4% error (>8 Myr), is of little use (Li et al., 2015).

提交时间: 2018-07-18 来自合作期刊:《古脊椎动物学报》 点击量1114下载量160 评论 0

5. chinaXiv:201808.00143 [pdf]

New ootype prismatoolithids from the Late Cretaceous, Laiyang Basin and its significance

WANG Qiang; LI Yu-Guang; ZHU Xu-Feng; FANG Kai-Yong; WANG Xiao-Lin
分类: 生物学 >> 生物学其他学科

Here we discribe a new ootypes of prismatoolithids found from the Late Cretaceous Jiangjunding Formation in the Laiyang Basin, Shandong Province. On the basis of characters such as elongate ovoids, smooth eggshell surface, relatively thinner eggshell thickness, prismatic eggshell units, slender pores in radial section of eggshell and little pores with round or irregular shapes in tangeital section of eggshell, we erect one new oogenus and one new oospecies: Laiyangoolithus lixiangensis oogen. et oosp. nov. The discovery of L. lixiangensis not only enriches the diversity and composition of the Laiyang Dinosaur Egg Fauna, but the paleogeographic distribution of primatoolithids as well. In addition, it provides more paleontological materials for the study of the diversity and paleogeographic distribution of troodontids in China.

提交时间: 2018-07-18 来自合作期刊:《古脊椎动物学报》 点击量1137下载量152 评论 0

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