分类： 地球科学 >> 地质学 提交时间： 2017-09-28 合作期刊: 《古脊椎动物学报》
MAO Fang-Yuan
LI Chuan-Kui
MENG Jin
LI Qian
BAI Bin
WANG Yuan-Qing
ZHANG Zhao-Qun
ZHAO Ling-Xia
WANG Ban-Yue
摘要： Tooth enamel is composed of elongated, hexagonal crystallites of hydroxyapatite. Some crystallites are arranged into various regual structures and futher formed a composite structure in a hierarchical manner. The hierarchical system can provide a basis for analysis different levels of structural complexity from varitaiton of particular crystallite strucutes to variation of structural types throughout a individual’s dentition. The size, orientation, distribution and the packing patterns of crystallites are gene-comtrolled and have limited range of intraspecific variability. Thus, these microstructures provide considerable and reliable morphological characters that help understanding of external dental morphology in context of both phylogeny and function in vertebrates. Because teeth are highly resistant to weathering, mainly owing to their enamel covering, so that they were commonly preserved as fossils. This organic system, particularly their microstructures, has attracted more and more attention from vertebrate paleontologists and other morphologists. However, as already recognized by many previous studies, some terminologies of the enamel microstructures have been complex and used inconsistently. Although considerable effort has been made to study enamel microstructures in China during the last few decades, a standard terminology of enamel microstructures in Chinese has not be formally brought into line with that in English literatures. Here we intend to introduce and systematize the relevant terminology used in the study of enamel microstructures and translate them into Chinese, in hoping that this systematic effort will enhance researches of enamel microstructures in China. 脊椎动物牙齿釉质显微结构具丰富的形态学特征，承载着系统发育和生物力学等方面的信息。本文在前人的研究基础上，试图系统地介绍牙釉质显微结构的基本内容，提出牙釉质研究中相关术语的中文译名建议，并对一些重要术语做了简要解释，供相关研究者参考，以期促进牙釉质显微结构研究的进一步发展。
分类： 地球科学 >> 地质学 提交时间： 2017-08-02 合作期刊: 《古脊椎动物学报》
摘要： Specimens reported in this note represent the frst discovery of Yuomys in Altun Shan. A new species, Yuomys altunensis, is established based on the following features: molars large and wide in proportion; metaconule distinctly separated from metacone, metaloph long, but incomplete; hypocone smaller than protocone; sinus extending to base of crown on lingual side; postcingulum connectting lingual side of metacone; metacone crescent and postcingulum short in M3. Yuomys altunensis is similar to Y. cavioides, Y. eleganes and Y. huangzhuangensis of late Middle Eocene in molar morphlogy. According to its evolutionary level, Y. altunensis is supposed as of late Middle Eocene in age, or slightly later. 记述了在新疆巴音郭楞蒙古族自治州若羌县阿尔金山地区彩虹沟首次发现的豫鼠一新种：阿尔金豫鼠(Yuomys altunensis sp. nov.)。其主要特征是臼齿的尺寸较大，比例上较宽，齿冠较高，臼齿的后小尖与后尖明显分开，后脊相对较长，但不完全，次尖明显小于原尖，舌侧内凹伸达臼齿齿冠基部，后齿带与后尖舌侧连； M3后尖为新月形，后齿带较短等。根据豫鼠臼齿的进化趋势和新种臼齿的尺寸较大、齿冠较高和舌侧内凹伸达齿冠基部的特征与Y. cavioides, Y. eleganes和Y. huangzhuangensis相近，但颊齿比例较宽判断 Y.altunensis可能与该3种处于同样的进化阶段或稍进步。其产出的地层时代很可能与它们相近或稍晚，即为晚中始新世或稍晚
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