This 65.5-million-year old layer of Earth separates fossils of the Cretaceous period from those of the Tertiary period.
他们发现当时被称为K-T边界的沉积层中含有浓度极高的铱元素,这个具有6,550万年历史的古老地层将白垩纪的化石与第三纪的化石分离开来。
Xixia ruins belong to the Cretaceous period dinosaur rift sedimentary basin.
西峡恐龙遗址属于白垩纪断陷盆地沉积。
One was an isolated feather dating from the Cretaceous period (about 100m years ago) that was found in Brazil.
其中一个是在巴西发现的白垩纪(约1亿年前)的一根羽毛。
This 65.5-million-year-old layer of Earth separates fossils of the Cretaceous period from those of the Tertiary period.
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。
Microraptoris one of many small, feathered dinosaurs found in what is now China that were alive during the Cretaceous period more than 66m years ago.
小盗龙,生活在距今六千六百多万年前的白垩纪,是现今中国境内发现的众多体型娇小、长有羽毛的恐龙之一。
Tyrannosaurus rex arose during the Cretaceous period about 85 million years ago and thrived as a top land predator until the dinosaurs went extinct 20 million years later.
霸王龙出现,在白垩纪时期约85万年前,和蓬勃发展作为最高的土地捕食,直到恐龙灭绝二千万年后。