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.

我想这些恐龙灭绝是因为它们无法适应在末期出现全球性环境变化。

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

我们在马里兰发现早期化石保存在砂岩和粘土岩中。

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

这种发现证明了这些蜥蜴王在就统治了海洋。

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

但这没阻挡恐龙在时在此筑巢。

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

风神翼龙可谓隐形轰炸机...它拥有最先进空地武器。

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.

这些岩心中最古老物质能够追溯到1.015亿年前中期，也就是恐龙在陆地上全盛时期。

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

在埃及沙漠中发现一种恐龙，为漫步于非洲野兽提供了新认识。

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

有些鸭嘴兽有50英尺长，但异域龙可能是最小素食者，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.

记载最完整这种灾难曾发生在6500万年前，在地质历史阶段末期。

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

我要删除“”、“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，这是恐龙世界巅峰时期，恐龙遍布全球。

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，在北美和欧洲不同谱系中，体型较大海龟独立发育。

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

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，因为这样景观在侏和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.

不同羽毛有不同颜色样式，这表明时期会飞恐龙和陆地恐龙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.

在一亿四千万年前，这种恐龙脖子上长着看起来很危险刺。

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

所有这些食草动物都有其复杂防御器官，它们都是很高级生物。

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松树，人们认为它自以来就已经灭绝，但在 90 年代，它在澳大利亚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.

被称为鸟脚亚目食草恐龙其地位相当于斑马和羚羊--每部有关非洲大草原录片中被捕杀种群。

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.

我们在了解时期世界这部分环境时，发现跟现在我们有没那么大区别。