I think these dinosaurs went extinct because they simply could not deal with the global environmental changes that were occurring at the end of the Cretaceous period.

我想这的灭绝是因为它们无法适应白垩纪末期出现的全球性的环境变化。

The early Cretaceous fossils that we find in Maryland are preserved in sandstones and clay-stones.

我们马里兰发现的白垩纪早期化石保存砂岩和粘土岩中。

Evidence that these lizard kings dominated the oceans in the Cretaceous period.

这种发现证明了这蜥蜴王白垩纪就统治了海洋。

But that didn't stop dinosaurs from nesting there during the Cretaceous period.

但这没阻挡白垩纪时此筑巢。

A Quetzalcoatlus could be seen as a Cretaceous stealth bomber... Air-to-ground weaponry at its finest.

风神翼可谓白垩纪的隐形轰炸机...它拥有最先进的空地武器。

The oldest material in these cores dated back 101.5m years, to the middle of the Cretaceous period, the heyday, on land, of the dinosaurs.

这岩心中最古老的物质能够追溯到1.015亿前的白垩纪中期，也就是陆地上的全盛时期。

A species of dinosaur discovered in an Egyptian desert has shed new light on beasts that roamed Africa in the Cretaceous period.

埃及沙漠中发现的一种，为白垩纪漫步于非洲的野兽提供了新的认识。

Some duckbills were 50-feet long, but Ajnabia was perhaps the smallest of these Cretaceous vegetarians, about the size of a pony.

有鸭嘴兽有50英尺长，但异域可能是白垩纪最小的素食者，只有小马那么大。

The best-documented such impact took place 65 million years ago at the end of the Cretaceous period of geological history.

记载最完整的这种灾难曾发生6500前，地质历史阶段的白垩纪末期。

I'm going to delete " cretaceous, " I'm going to delete " Cenozoic" and I'm going to delete " iridium."

我要删除“白垩纪”、“新生代”、“铱”。

We get into the Cretaceous period, that's kind of the flower of the dinosaur world and dinosaurs are cosmopolitan.

进入白垩纪，这是世界的巅峰时期，遍布全球。

The findings suggest large sizes in marine turtles developed independently in separate Cretaceous lineages in North America and Europe.

研究结果表明，北美和欧洲不同的白垩纪谱系中，体型较大的海龟独立发育。

In the case of pelagornithids, this particular role would be filled by flying reptiles in the Cretaceous period.

白垩纪时期，飞行爬行动物会取代 pelagornithids 这一特殊角色。

That is fair enough. Such landscapes were common during the beasts' heydays, the Jurassic and Cretaceous periods.

这很合理，因为这样的景观侏罗纪和白垩纪的野兽鼎盛时期很常见。

Different feathers have different patterns of colour, suggesting that Cretaceous dinosaurs-flying or otherwise-used their feathers for display.

不同的羽毛有不同的颜色样式，这表明白垩纪时期的会飞和陆地都利用羽毛来炫示自己。

During the Cretaceous period, 140 million years ago, this dinosaur sported a neck of dangerous looking spines.

一亿四千前的白垩纪，这种的脖子上长着看起来很危险的刺。

All these Cretaceous plant eaters, with their complicated apparatus, they're all much more sophisticated.

所有这白垩纪的食草动物都有其复杂的防御器官，它们都是很高级的生物。

There's a pine tree called the Wollemia pine that was thought to have been extinct since the Cretaceous period, and in the nineties, it was discovered alive in a valley in Australia.

还有一种叫沃勒迈松的松树，人们认为它自白垩纪以来就已经灭绝，但 90 代，它澳大利亚的一个山谷中被发现仍然存活。

The Cretaceous equivalent of zebra and antelopes-the victim species in every wildlife documentary about the dramas of the African savannah-were herbivorous dinosaurs called ornithopods.

白垩纪被称为鸟脚亚目食草其地位相当于斑马和羚羊--每部有关非洲大草原的纪录片中被捕杀的种群。

When we look at the Cretaceous environments of this part of the world, it's not all that different than environments that we still have today.

我们了解白垩纪时期世界的这部分环境时，发现跟现我们有的没那么大区别。