这个有着6550万年历史的地层分离了白垩纪的化石和第三纪的化石。
This 65.5-million-year-old layer of Earth separates fossils of the Cretaceous period from those of the Tertiary period.
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."
在犹他州和阿拉斯加州还发现了另一种鸟的“足迹”化石，但都无法追溯到白垩纪早期——恐龙时代的鼎盛时期。
Other bird "trace" fossils have been found in Utah and Alaska, but none from so far back as the early Cretaceous -- at the height of the age of dinosaurs.
他说：“化石记录一再证实现代胎盘类哺乳动物的起源是在白垩纪-早第三纪分界点的时候或那之后。
“The fossil record continues to show that the origin of modern placental mammals postdates or is at the Cretaceous-Paleogene boundary, ” he said.
红层下蕴藏着大量的古生物化石。1961年广东区测队采得的晚白垩纪恐龙化石非常珍贵，是全世界研究恐龙的最佳地方。
Red layer under the vast deposits of fossils. 1961 Guangdong Ou team mined by measuring the Late Cretaceous dinosaur fossils are very rare, is the world's best place to study dinosaurs.
山东诸城是我国研究白垩纪地层和古生物的经典地区之一，特别以产出晚白垩世鸭嘴龙类恐龙化石群而闻名中外。
Zhucheng City of Shandong Province is one of classic areas for the study on Cretaceous strata and fossils in China, yielding rich Late Cretaceous hadrosaurid dinosaurs famously.
多骨刺鱼的化石显示白垩纪时它们在欧洲和非洲的水域中游弋。
Fossils of Caproberyx indicate they swam the waters of Europe and Africa during the Cretaceous period.
文中还介绍了我国白垩纪几个沉积盆地的生物地层和一些具有特色的蛋化石种类；
This paper gives descriptions to biostratigraphy of Cretaceous sedimentary basins and egg fossils from these basins;
其中之一便是一直杳无踪迹的来自白垩纪时期的保存良好的的羽毛化石。白垩纪处于一亿四千五百万年前到六千五百万年前之间，以恐龙的大规模灭绝为结束标志。
One such lacuna has been the absence of well-preserved feathers from the Cretaceous—the period between 145m and 65m years ago that ended with the mass extinction that wiped out the dinosaurs.
其中之一便是一直杳无踪迹的来自白垩纪时期的保存良好的的羽毛化石。白垩纪处于一亿四千五百万年前到六千五百万年前之间，以恐龙的大规模灭绝为结束标志。
One such lacuna has been the absence of well-preserved feathers from the Cretaceous—the period between 145m and 65m years ago that ended with the mass extinction that wiped out the dinosaurs.
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