但是很不幸的是，这段迅速的进化过程发生于中白垩纪的一千五百万年间，而这段时期的鲜有化石记录。
"But there were a hundred million years of evolution to play with."
海洋沉积物中浮游生物的这种变化标志着白垩纪和第三纪的分界线。
This change in plankton found in marine deposits is what marks the boundary between the Cretaceous and the Tertiary.
来自不同来源的数据，包括存留在海底沉积物中的地球化学依据，表明晚白垩纪的气候比如今的要温和。
Data from diverse sources, including geochemical evidence preserved in seafloor sediments, indicate that the Late Cretaceous climate was milder than today's.
地质记录中的其他几次大规模物种灭绝也被认为影响重大，但没有哪一次像白垩纪大灭绝那样夸张。
Several other mass extinctions in the geological record have been tentatively identified with large impacts, but none is so dramatic as the Cretaceous event.
曾经称霸地球显赫一时的恐龙，在白垩纪时代的这次温度巨变中，似乎全都灭绝了。
The temperature drop during the Cretaceous period would almost certainly have wiped out an 'abundance' of the world's dinosaurs.
白垩纪末期，当小行星撞击地球使得地表上的光合作用停止。生长速度较快的恐龙无法在这场危机中幸免于难。
Fast-living dinosaurs were unable to survive the crisis at the end of the Cretaceous, when an asteroid hit Earth and brought photosynthesis to a halt.
世界各地的白垩纪末期遗址中，科学家发现了超过100处有铱含量高得异常的层位，采集到变形石英标本的遗址也超过30处。
Scientists subsequently found enhanced iridium levels at more than 100 end Cretaceous sites worldwide and shocked quartz at more than 30 sites.
松辽盆地深层早白垩纪断陷内充填了大量火山岩和碎屑岩地层，在其火山岩地层中已发现了丰富的天然气资源。
There are a great number of volcanic and clastic rock formations in deep Early Cretaceous fault depression in Songliao Basin, abundant gas resource have been discovered in volcanic reservoirs.
藏南定日地区在白垩纪中期发育一套浅灰色深灰色的以钙质页岩、泥灰岩及微晶灰岩为主的浅海陆棚相沉积，岩石中除含较高的粘土矿物及陆源石英矿物颗粒以外，还含有十分丰富的有孔虫化石。
The Middle Cretaceous shallow sea sediments, represented by a series of light dark gray marine clastic and carbonate rocks, were well exposed along the Gongzha Section in Tingri, southern Tibet.
Santee海岸储藏岩心是从加州南部的查尔斯顿的545英尺深的钻井中采集的，代表白垩纪晚期、古新世、始新世和第四纪的沉积物。
The Santee Coastal Reserve core, a 545 ft deep borehole in northeastern Charleston County, South Carolina, recovered sediments of Late Cretaceous, Paleocene, Eocene, and Quaternary age.
东北地区中新生代盆地演化经历早侏罗世裂陷盆地、中晚侏罗世分割式前陆盆地、晚侏罗世末期至白垩纪裂谷盆地及新生代裂谷盆地四个演化阶段。
Basin evolution in ne China goes through four stages: early Jurassic rift basin, middle-late Jurassic partitioned foreland basin, late late Jurassic-Cretaceous rift basin and Cenozoic rift basin.
东北地区中新生代盆地演化经历早侏罗世裂陷盆地、中晚侏罗世分割式前陆盆地、晚侏罗世末期至白垩纪裂谷盆地及新生代裂谷盆地四个演化阶段。
Basin evolution in ne China goes through four stages: early Jurassic rift basin, middle-late Jurassic partitioned foreland basin, late late Jurassic-Cretaceous rift basin and Cenozoic rift basin.
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