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THE LATE-GLACIAL DEPOSITS AT GLANLLYNNAU, CAERNARVONSHIRE   总被引:6,自引:6,他引:0  
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LATE-GLACIAL DEPOSITS NEAR CAPEL CURIG, CAERNARVONSHIRE   总被引:5,自引:5,他引:0  
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RADIOCARBON DATES AND VEGETATIONAL HISTORY OF THE BRITISH ISLES   总被引:12,自引:10,他引:2  
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山顶洞遗址的第二批加速器质谱^14C年龄数据与讨论   总被引:9,自引:4,他引:9  
陈铁梅 《人类学学报》1992,11(2):112-116
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DIATOMS FROM NEASHAM LATE-GLACIAL DEPOSITS   总被引:1,自引:1,他引:0  
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云南禄丰晚中新世的大熊猫祖先化石   总被引:4,自引:3,他引:4  
本文对1981年以前和1983年在云南禄丰古猿产地发现的,为本文后一作者于1984年和1985年订为Ursavus depereti的化石材料进行了再研究。通过对标本的仔细观察及与有关属种的对比,作者将上述化石材料订为一新属新种Ailurarctos lufengensis gen.et sp.nov.。此种动物在形态特征和系统关系上介于Ursavus和Ailuropoda之间,它很可能代表了目前已知大熊猫类最早的祖先类型。  相似文献   

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首次描述埋葬于长兴期海相地层中的一个高地植物群,计14属23种,包括4新种,2相似种和11未定种。概略论述植物群的性质及其埋葬特征和生态意义。以松柏植物和Taeniopteris等为代表的裸子植物在这一植物群中占61%,显示由古生代向中生代过渡的性质。这一植物群与华北同期的高地植物群在属种组成上很不相同,显示两地在区系性质上的差异。  相似文献   

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桑干河流域晚更新世介形类   总被引:1,自引:0,他引:1  
本文研究了河北涿鹿县桑干河南岸二级阶地上更新统吉家营组的介形类化石,描述5科9属12种,其中1新种、1未定种。本文对介形类的生态环境也作了初步探讨,认为晚更新世此区属淡水、浅水环境,气候偏冷。  相似文献   

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安徽繁昌早更新世人字洞古人类活动遗址及其哺乳动物群   总被引:8,自引:0,他引:8  
1998年,在安徽繁昌县癞痢山发现了两处洞穴、裂隙堆积。在随后两年中对其中之一的人 字洞进行了系统发掘,采集到一定数量的石制品、骨制品和属种丰富、生态习性多样的大量脊 椎动物化石。人字洞发育于三叠纪灰岩中,洞穴堆积物厚约30米,可分为上下两个堆积单元, 脊椎动物化石和古人类遗物主要产于上堆积单元。经初步研究,人字洞动物群包含67种哺乳动 物,与我国南、北方第四纪早期的其它主要动物群相比,其绝灭属、种比例更高,动物群中主 要属种的形态特征更原始,然而该动物群中真马(Equus)的出现,表明其地质时代为早更新世 早期。这一动物群具有浓郁的北方色彩,显示出更新世初期我国境内有一次明显的降温事件,促 使北方动物大规模向南迁徒,在长江以南形成东洋界和古北界动物地理区系交错带的过渡区动 物群。人字洞动物群的发现为研究我国第四纪早期动物群的特征和动物地理区系演化及古气候 环境变迁提供了重要的信息。  相似文献   

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PIGMENTS FROM THE BOTTOM DEPOSITS OF AN ENGLISH LAKE   总被引:4,自引:1,他引:3  
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甘肃党河地区第三纪中期的跳鼠化石   总被引:3,自引:3,他引:0  
描述了产自甘肃省党河地区第三纪中期的跳鼠化石 3属 7种。其中 5种 (Parasminthusasiae centralis,P .tangingoli,P .parvulus,Heterosminthuslanzhouensis和LitodonomyscfL .huangheensis)产自狍牛泉组上部 ,时代为晚渐新世。产自早中新世 (?)铁匠沟组中部的 2种是中间异蹶鼠 (新种 ) (Heterosminthusintermediussp.nov .)和西水简齿鼠 (新种 ) (Litodonomysxishuiensissp .nov .)。Heterosminthusintermedius的主要特征是 :M2的前齿带较短而低 ,m1的下次脊较向前斜伸 ,与下中尖前的下外脊相连 ;在颊齿的宽窄比例和其他一些特征上介于H .orientalis和H .lanzhouensis之间。Litodonomysxishuiensis的主要特征为 :下臼齿比例上较宽短 ,下外脊位于纵中线附近 ;下中脊在m1中长 ,在m2中无 ;m2和m3下前边尖很发育 ,但孤立 ;m3下中凹和下外凹明显缩短等。探讨了Heterosminthus和Litodonomys的进化趋势和铁匠沟组中部的时代。  相似文献   

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Thick mats of cellular remains from Eocene brown coal deposits of the Geiseltal near Halle, DDR, were determined to be fossil nonarticulated laticifers. Nuclear magnetic resonance analyses of intact strands showed they consisted of eis-1,4-configuration rubber representing the polymerized isoprenoid contents of individual laticifers. Only remains of laticifers are present; other cells are absent as a result of biodegradation. The long laticifers, often with a surrounding cell wall, retained a tubular shape during their preservation. The isoprenoid content, which filled the entire lumen, possessed a cribriform structural character. The interstices within the rubber represent areas of former protoplasm of the cell. Various configurations in the protoplasm molded by the rubber during the initial phase of fossilization appear as negative images of former nuclei, organelles, and possibly membrane surfaces. The laticifer axes possess branches of several configurations comparable in morphology to those in branched, nonarticulated laticifers in extant plants. Acetone extracts of the rubber contents analyzed by gas-liquid chromatography identified the presence of several hydrocarbons which form a characteristic profile for the laticifer. It is suggested that the distinctive cellular micromorphology, rubber configuration, and hydrocarbon profile of these laticifers can be employed as markers in comparative studies with extant plants to identify the generic or species origin of these laticifers.  相似文献   

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内蒙古阿左旗乌兰塔塔尔地区的渐新世地层中,哺乳动物化石丰富,种类繁多。本文是这个动物群研究的初步报道,除对动物群中各成员和地层概况做了简单介绍外,还对化石层的时代作了初步探讨。  相似文献   

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Abstract:  A new species of the plesiomorphic wombat Warendja is described. Warendja encorensis sp. nov., the second species to be attributed to this genus, is known from a single fossil locality (Encore Site) at Riversleigh, north-west Queensland. Specimens of W. encorensis are limited to isolated teeth, two mandibular fragments and a maxillary fragment. Two molars preserve the unworn crown morphology. Encore Site has been estimated to be late Miocene in age, making these the only known specimens of Warendja to be clearly older than Pleistocene. Warendja encorensis is also the first described species of wombat from Miocene deposits to which hypselodont teeth have been attributed. It differs from W. wakefieldi in its larger size, distribution of enamel, and in details of the incisor and premolar morphology.  相似文献   

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