白垩纪的

Based on properties of the rock attached to some of the fragments, Arbour and her colleagues think the specimen may date to about 70 million years ago in the Upper Cretaceous Period.

基于附着在骨骼上碎石的特性，阿伯尔和她的同学们认为这一物种生活在0.7亿年前白垩纪早期。

The biostratigraphy of Cretaceous/Tertiary boundary sections from eight localities is summarized and compared in order to define a continuous or complete section.

本文总结了八个地区白垩纪—第三纪界线的生物地层资料，试图确定一个完整的连续剖面。

Based on the study of biostratigraphy and anoxic eventstratigraphy, we propose that the Qingshankou Formation may correspond to the oceanic anoxic event at the CenomanianTuronian boundary in the Cretaceous, and the age of the Qingshankou Formation in the Songliao Basin is the Late Cenomanian to the Early Turonian.

结合生物地层研究成果，认为青山口阶下部曾发生过古湖泊缺氧事件，其层位大体可与白垩纪古海洋CenomanianTuronian界线事件层进行对比，由此提出了松辽盆地青山口阶下部的时代归属于晚白垩世Cenomanian晚期-Turonian早期的新观点。

One confounding factor is that the late Cretaceous was also a period of great volcanic activity.

令人生疑的一个因素是，白垩纪末期也是个火山剧烈活动的时期。

The cretaceous is the dinosaur life, but also the great changes of landscape.

白垩纪是恐龙生活的最后一个纪，也是地球景观发生巨大变化的时期。

The really strange thing is that there is absolutely no hint of anything happening at the end of the Cretaceous.

真正让人感到不解的是，在白垩纪时代所发生的一切变化却找不到任何线索。

The most famous case of this is the large dinosaurs that disappeared by the end of the Cretaceous, he said.

最有名的是大型恐龙在白垩纪晚期消失的例子。

They diversified and evolved, and dominated the Earth during the Jurassic and Cretaceous periods that followed.

他们多元化的演变着，并在侏罗纪和随后的白垩纪时期主宰着地球。

The trip visits Spurn Point, Holderness, Scarborough, Sewerby and Filey Brigg. Topics discussed include: erosion; the effect of geology on urban development; paleocliffs; Jurassic reefs; chalk cliffs and jet rock.

网站还提供了一些主题讨论，主题涉及到海水侵蚀、地质变化对城市发展的影响、侏罗纪时期暗礁介绍、白垩纪时期悬崖介绍及黑玉岩介绍等内容。

During the Early Cretaceous, southeastern Australia was both a nursery and a refugium for terrestrial vertebrates.

在早白垩纪，澳大利亚的东南为陆地脊椎动物是一和一幼儿园refugium。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。