Our Favourite Sir David Attenborough Moments | BBC Earth Science

追加: 2026-05-12

[00:00:00]I started looking for fossils when I was a boy, and I've never lost the feeling of excitement and anticipation of what one might discover.

[00:00:14]The commonest fossils here are coiled shells called ammonites, and you can find them all over the place. There's one here on this boulder. You can see the whs there, but it's mostly been worn away by the sea. But sometimes, if you're lucky, you can find nodules like this. And if you look at them, you can see there's the edge there of a an ammonite. And if I hit it, I put it on protective glasses. If I hit it, it should How about that?

[00:00:54]Wow.

[00:00:56]What a find.

[00:01:00]Ammonites, in fact, are quite common on this beach. But every now and again, something truly rare and spectacular is found here, and quite often by this man, one of the most skilled fossil hunters I know.

[00:01:17]Chris Moore has been collecting fossils here for more than 30 years.

[00:01:23]Recently, he came across a boulder which he thought might contain something unusual.

[00:01:30]Back in his workshop, he exposed the mosaic of small, beautifully preserved bones, which he knew straight away were the front fins, the paddles of an ichthyossaur.

[00:01:43]But they were unlike any he had ever seen before.

[00:01:55]I still collect fossils.

[00:01:59]I even have the remains of anthosiosaur, a small one of a kind that's relatively common.

[00:02:09]This was collected by Chris about 10 years ago in Dorset. I never found anything as beautiful as this. It's got jaws and it's got teeth and it's got paddles.

[00:02:21]And Dorset was the very first place where they found a really complete skeleton of one of these creatures. This is a picture of it published for the very first time in 1814.

[00:02:37]Well, people thought it was some kind of monster. But what was it? They thought it was a kind of cross between a reptile and a fish. So they called it an ethosaur, a fish lizard or sea dragon.

[00:02:55]After weeks of work, Chris has exposed the backbones and ribs.

[00:03:01]>> So this is it so far.

[00:03:03]>> And in doing so, he's made a startling discovery.

[00:03:07]>> It looks like it's been attacked. Gosh, this breakage is all through the rib cage. If you follow one rib, you go along here down to here, then this piece corresponds to this, which then goes over to here. So, >> oh, there. Yeah.

[00:03:21]>> One rib is now broken into three pieces.

[00:03:26]How extraordinary. But what's happened here?

[00:03:30]>> Here, the vertebra column has been actually pulled away. I'm fairly positive it was done in life. And the paddles, the flippers have been ripped off.

[00:03:40]>> Where where would they go?

[00:03:50]But they're in a very odd position, aren't they? I mean, they're pointing the wrong direction. They should be basically in this position and facing the other way up. And they've been ripped off and turned over.

[00:04:05]Gosh.

[00:04:06]Well, where was the head?

[00:04:08]>> The head should be here. That's the very last vertebrae.

[00:04:12]>> Back of the neck.

[00:04:13]>> Yeah.

[00:04:14]>> So, the head's been torn off. And there's no evidence. There's no teeth or pieces of bone. It's completely gone.

[00:04:23]>> So, it it's a murder.

[00:04:25]>> Yes.

[00:04:27]>> Really?

[00:04:27]>> Yeah. I think it was killed.

[00:04:29]>> Did this predator crunch the head, do you think?

[00:04:31]>> Who knows? You know, it's 200 million years ago. Uh, it's a bit of guess work really, isn't it?

[00:04:37]>> So, it's um a murder story without a complete body yet.

[00:04:44]>> To find out more, we need to reveal the rest of the skeleton.

[00:04:50]So, it's all hands on deck.

[00:05:06]They've even roped me in.

[00:05:20]This is more difficult than it looks.

[00:05:28]Very good.

[00:05:31]Could you Could you start on three days a week?

[00:05:35]>> Is it all right? And haven't gone too close to the bone.

[00:05:38]>> No. No.

[00:05:39]>> Oh, that's a relief. All the blocks containing the fossil have now been scanned. With those scans, the team were able to separate the individual bones and then put them back together to create a 3D image of the ichthosaur's body before it was attacked.

[00:06:00]They've added a head based on estimates of others species.

[00:06:07]That's magnificent. This is the whole animal and we estimate that it may have been up to around about 4 and a half meters long.

[00:06:14]>> Is that bigger than most than?

[00:06:16]>> Yes, this is certainly bigger than most of the ichthyosaurs that we see at Lime Regis.

[00:06:20]>> Looks huge. Looks amazing.

[00:06:22]>> Here are the four limbs right at the front and we've got hind limbs here and at the back we've got a tail bend. This is supported by the backbone which extends along the whole length of the body.

[00:06:32]>> But that bend is natural, isn't it?

[00:06:34]That's not a bra. that gives strength to the lower element of the tail for driving it forward.

[00:06:39]>> Much like a shark, the tail bend is the main propulsive organ of the animal.

[00:06:44]>> So, could this be a new species?

[00:06:47]>> Yes. These pieces of evidence together suggest that it is going to be a new species and it's jolly exciting. They don't come along every day.

[00:06:54]>> Historic.

[00:06:55]>> Yes.

[00:06:58]>> This is wonderful news. A sighting by Chris on the beach in Lime Regis has led to the discovery of a new species of ichthyossaur adding to our knowledge of these fascinating creatures.

[00:07:11]It's extraordinary how much you can discover from one single fossil. Digital reconstruction has allowed us to rebuild this animal to reveal how it looked and how it moved.

[00:07:24]We've discovered for the first time that this creature was countershaded, but that didn't stop it from being attacked.

[00:07:34]By analyzing its bones, you've been able to work out that its most likely attacker was a Teodonttosaurus, the most ferocious predator of the seas at that time.

[00:07:49]It's been a fascinating journey of discovery, but for me, the real wonder is the bones themselves. I can't wait to see what they look like when they're finally cleaned.

[00:08:14]After many months of painstaking and patient preparation, Chris and his team have finally completed their work on the fossil of our ancient sea dragon.

[00:08:36]Here it is finished.

[00:08:40]Wow.

[00:08:42]It It's really beautiful, isn't it? I mean, it is beautiful. That's for sure.

[00:08:48]>> Thank you. It's a great specimen, isn't it?

[00:08:50]>> Lovely. And how many new species have been discovered in the last 100 years?

[00:08:56]>> Very few. Very, very few. And it's thrilling to find something that that's, you know, just never been seen before.

[00:09:09]Around 80% of the earth's animal species are insects.

[00:09:14]They play a vital role in the food chain, essential to many birds, fish, and other animals.

[00:09:21]They fertilize and airate the soil. And of course, they pollinate.

[00:09:28]Without them, life as we know it would cease to exist. So, with only three places left on my ark, it would seem wrong not to include at least one.

[00:09:45]Butterflies lift the heart.

[00:09:51]There are thousands to choose from, but this butterfly house has one of my favorites.

[00:10:01]I've selected it for its exquisite beauty.

[00:10:10]This is a triams birdwing butterfly. It lives in western New Guinea and to the islands both east and west and also down into the northern part of Australia.

[00:10:25]Bird wings have some of the largest of insect wings and are very sought after by collectors.

[00:10:33]The name comes from their rather bird-like forewings.

[00:10:41]The male pam birdwing has a striking pattern of vibrant green and black.

[00:10:53]The females are larger and less colorful, but just as delightful.

[00:10:59]These butterflies are able to fly long distances high above the forest canopy.

[00:11:20]But these beautiful insects only live for about 10 days as fully formed adult butterflies.

[00:11:32]If I take him on board my ark, I'm not going to have him for long.

[00:11:38]But in the 10 days of his short life, he'll bring such joy that I'm delighted to have him on board.

[00:11:48]Huh? Doesn't want to leave. Off you go.

[00:11:53]Off you go.

[00:11:58]Okay, stay on board. I'm in Arizona, and that at my feet is a lizard buried in the sand up to its neck.

[00:12:10]Even while it's buried, it can use the sunshine to warm its whole body. it can control the supply of blood to its head so that it pools in a cavity behind the eye.

[00:12:22]Soon the blood there is as much as 5° above the temperature of the rest of its body.

[00:12:28]Then the animal opens the major blood vessels in its neck and the hot blood circulates so that its whole body is thoroughly warmed even though it's still mostly below ground.

[00:12:46]This is a horned lizard and very beautiful too. This particular species is called the regal horned lizard because it has this splendid crown of spikes at the back of his neck.

[00:13:03]When he's hidden, they break up the outline of his head and so you hardly see him at all. And now in the warmth of my hand and in the sunshine, I guess he's warmed up quite a lot. And if I put him down, he now at last may be able to run for it.

[00:13:21]>> And indeed he does.

[00:13:31]South African armadillo lizards, which live on these rocky outcrops, have a different solution to the problem of safe sunbathing.

[00:13:41]They've turned it into a social activity.

[00:13:46]Whole families of them live together in the crevices among the rocks, and in the morning, they all emerge to warm up in the sun.

[00:13:56]Of course, there is safety in numbers.

[00:14:00]There are lots of eyes to spot danger if it appears.

[00:14:16]And when one sunbather takes fright, they all dive for safety.

[00:14:22]If a predator is quick, it is possible to grab one. But even then, an armadillo lizard is not going to be an easy meal.

[00:14:29]>> Oh, they have an additional form of defense.

[00:14:35]They bite their tails.

[00:14:38]The reason they do that is that it covers up their vulnerable underside and exposes only these very sharp spiny scales, which is very good protection against predators like snakes or monguses.

[00:14:57]And they stay like this for quite a long time before they're confident enough to uncurl. I'll put him down and see how he does.

[00:15:18]a leopard gecko. It, like most geckos, is nocturnal, and it manages to get all the heat it needs from the rocks, which retains something of their warmth for several hours after the sun has set.

[00:15:31]This male is in search of a mate.

[00:15:34]She is less brightly colored.

[00:15:41]They inspect one another.

[00:15:48]He collects her scent with his tongue and discovers that not only is she female, but she's sexually available.

[00:16:02]He's interested.

[00:16:08]He nibbles her neck and strokes her flanks. All part of his elaborate courtship routine.

[00:16:22]Culation begins.

[00:16:27]This is the time in mammals and birds when the sex of the young is determined.

[00:16:32]but not in a number of reptiles, including geckos. Once again, it's temperature that profoundly influences their lives.

[00:16:42]The female goes away to lay her eggs.

[00:16:48]She has chosen a place where the temperature is about 31°.

[00:16:52]As her body is the same temperature as her environment, she can't heat her eggs by sitting on them as warm-blooded birds do. So they're exactly the same temperature as the rocks beneath.

[00:17:06]After a couple of months, both eggs begin to hatch.

[00:17:14]The first to emerge is a male and the second will be two. It's the temperature which has determined that if it had been a few degrees lower, both eggs would have developed into females.

[00:17:39]This tiny poison arrow frog is carrying his tadpole pig. It hatched on a leaf and now he's taking it to a pool in a bromeilad high up in the branches.

[00:17:51]The tadpole wiggles off.

[00:17:55]He may have half a dozen babies, each of which he puts into its own tiny pool.

[00:18:09]He makes regular tours of all his nurseries, checking on his tadpole's welfare.

[00:18:23]This youngster is hungry and tells him so by nibbling his legs and vibrating against his body.

[00:18:35]But the male can't feed the tadpole himself. He needs help.

[00:18:49]He has to find a female.

[00:19:00]There she is.

[00:19:07]He calls and she follows.

[00:19:27]He has to lead for only he knows exactly where he deposited each tadpole.

[00:19:35]This one is now very hungry indeed.

[00:19:43]He calls to the female encouragingly.

[00:19:51]She jumps in perhaps to assess the situation.

[00:19:58]Out she comes without having done what's required. So he keeps calling.

[00:20:05]In she goes a second time. This time she produces food for the hungry tadpole.

[00:20:12]An infertile egg.

[00:20:18]There out she comes and mother and father embrace.

[00:20:41]Baby has its dinner.

[00:20:49]This is a South American redeyed tree frog. A close match for the leaves on which it habitually sits.

[00:21:00]The eggs are not very conspicuous either, just little blobs in transparent jelly. And they're always laid over water.

[00:21:14]They develop very rapidly.

[00:21:37]In less than a week, they've become recognizable tadpoles, almost ready for freedom.

[00:21:44]Then the jelly liquefies, and they simply drop into the water beneath.

[00:21:51]But some don't survive long enough to do so.

[00:21:59]Wasps raid the cluster and carry off the unhatched tadpoles to feed their young.

[00:22:35]But the tadpoles are not entirely helpless.

[00:22:40]By the time they're 5 days old, they know when they're under attack. And what's more, they can do something about it.

[00:22:50]there.

[00:22:52]Quick wiggle and a tadpole drops to safety.

[00:23:04]The alarm spreads quickly through the whole cluster and they all take a dive.

[00:23:13]Their tails are not yet fully developed, but they can swim well enough to take refuge beneath the leaves of the water plants.

[00:23:52]So if there's a choice between being carried off by a wasp and taking an early bath, there's no competition.