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9 Posts tagged with the palaeontology tag
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Fascinating giants that roamed four continents from circa 700,000 to 4,000 years ago: woolly mammoths (Mammuthus primigenius) have been the subject of countless conversations here at the Museum in recent months. So Nature Live thought they would go with the flow by tackling the question of just 'Why did the mammoths go extinct?' Prof Adrian Lister, an expert in vertebrate palaeobiology, led this Nature Live and presented the two main arguments.

 

Climate problems?

 

The first argument Adrian presented was the climate change theory: that mammoths used to rely on grasses as their primary food source, and were exclusively vegetarians. These grasses produced a meadow-like landscape, which was a hugely rich and high quality food source for the mammoths.

At the end of the last ice age, around 14,000 years ago, a warming climate caused forest habitat to spread north and gradallly replace grasslands that the mammoths relied on for food.

 

During the last ice age, these grass meadows expanded across the northern hemisphere, expanding the mammoths' geographic range. These grass meadows were above the tree line, as the grasses could successfully survive in lower temperatures than trees. Here fascinating video footage lit up the Attenborough Studio's big screens, showing the growth and change of distribution of these meadow grasslands across the last ice age.

 

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Woolly mammoths roamed the earth between ca. 700,000 to 4,000 years ago, before they were driven to extinction.

 

Adrian then described the range of specialist adaptations that woolly mammoths used to survive in this extreme habitat. The most obvious of these was the thick hair which insulated them from the harshly cold weather conditions. It turns out that mammoths actually had two types of hair: a very fine hair close to the skin trapping and warming the air for insulation, and a coarser hair on the outside to help shield them from cold wind and rain. In addition to these adaptations, woolly mammoths also had a thick layer of fat underneath their skin to further insulate them.

 

To the audience's amazement at this point a true sample of woolly mammoth hair was put underneath the visualiser in the Studio. The hair was thousands of years old yet fully intact, but this was only the start. Adrian then stepped forward to pick up a whole mammoth lower jaw, illustrating how it would swing back and forth when chewing.

 

Holding this in his hands in front of the live audience visually demonstrated just how large the teeth of a mammoth were, and the large size of the surface area required for chewing tough plant material like grass. Adrian made it clear that studying mammoth teeth gives researchers a much clearer idea of what they ate. With this increased understanding of what mammoths ate, researchers can better pinpoint factors that could have eventually led to their extinction.

 

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A woolly mammoth lower jaw like the one presented during the Nature Live by Adrian Lister, demonstrating their huge teeth used for grinding plant matter.

 

Frozen mammoths have even been discovered with food content still inside their stomachs or intestines, their 'last supper', as it were. Studying these remains of partially digested plant matter taken from inside a preserved woolly mammoth has proven that they certainly did eat grass as a food source.

 

Knowing for sure that mammoths ate grass supports the climate change theory of habitat change, as the grass plains began to contract at the end of the last ice age around 14,000 years ago. This was because the earth's climate was warming, and forest habitat was spreading north so gradually displacing the grasslands that mammoths relied on for their food.

 

Adrian explained how, by using radiocarbon dating, we can age mammoth remains very accurately, and this has now been used to age and plot every mammoth fossil ever found. This in turn means that scientists like him can identify and mark the change in woolly mammoth distribution over time. This crucial extinction timeline can then be matched against the known changes in reduced grass cover and the increased spread of forest growth up into the woolly mammoth's natural range.

 

When scientists compare the changing distribution of woolly mammoths to the changing distribution of their grasslands, they match. This suggests that the spread of the forest upwards into the higher latitudes would have pushed the woolly mammoths north. So it was this change in vegetation from grassland to forest that was a major contributing factor, ultimately leading to the mammoth's extinction.

 

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As the woolly mammoths' range contracted they became extinct. Studying them now could help prevent future mammal extinctions.

 

At this point Adrian then put forward a second theory, saying that "nothing in science is ever that simple." This second theory is that early humans could themselves have been responsible for driving the woolly mammoths to extinction. 

 

Hunted to extinction?

 

Evidence for the 'people theory' is that the period of time that woolly mammoth numbers were declining also coincided with a rapid increase in the numbers of people. There have been skeleton remains of mammoths found which show damage from a flint tool splintered off in the bone. In the studio, images of this were brought up on the screen, clearly showing a human-crafted spearhead lodged within a mammoth bone. This is evidence that early humans did at least occasionally hunt mammoths as large game, either as a source of food, or for materials to build shelter.

 

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Flint spear heads have been found splintered-off within mammoth fossils proving that they were occasionally hunted by early humans.

 

As this Nature Live approached its end, Adrian explained that both of these theories could in fact have worked together at the same time to conspire against the woolly mammoth, thus driving it to extinction. The change in the climate driving forests to spread north would have forced the woolly mammoth into very restricted habitat patches, making them a heavily endangered species; this, combined with hunting by humans could have dealt the final blow to the woolly mammoths, sending them to the icy grave of extinction.

 

The event did end on a more positive note when Adrian explained that the woolly mammoths' death was not in vain. Studying and understanding the reasons why large mammals like mammoths went extinct could help scientists like Adrian prevent the extinction of other large mammals in future. And research on mammoths is now being used to help try and protect African elephants (Loxodonta africana) from following their footsteps.

 

Watch Adrian summarise the theories behind the extinction in the Museum's film from the Mammoths: Ice Age Giants exhibition, which closes on 7 September:

 

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With our satellite dish at the ready, the sun shining and half a dozen Museum scientists raring to go, last weekend's Nature Live events went down a storm!

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Linking back to the studio from the harbour in Lyme Regis, we brought the annual Fossil Festival to South Kensington. For visitors who were unable to visit the south coast in person, we revealed why Lyme Regis is THE place to go fossil hunting and showed our audiences some of the weird and wonderful specimens that can be found there.

 

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Museum curator Zoe Hughes reveals an Ammonite, found in the local area.

 

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Does this count as Big Pond dipping?

 

Sunday's events brought us up to date with the organisms that call our seashore home. I was out first thing trying my luck with my bucket and net. I think I was the oldest 'rock-pooler' on the beach!  Unfortunately, I didn't manage to find very much, except for lots of seaweed ... but this proved to be far more interesting than I had first thought!

 

Museum scientist Lucy Robinson explained that there are many different species of seaweed to be found along our coastline, varying in colour, shape and size. She also explained the various ways seaweeds and their extracts can be used - in toothpaste, ice-cream, fertilizer and cosmetics (to name but a few).

 

And of course, some types of seaweed can be eaten - such as sea lettuce. Lucy and I decided to give it a go ... our conclusion, it's very salty and a bit crunchy (but I think that may have been sand!)  To find out more about seaweed and how to identify them, visit our Big Seaweed Search pages.

 

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Yum!

 

Lyme Regis is a great place to visit at any time of the year. If you're interested in fossil hunting, look out for the many guided walks that are on offer throughout the year, giving you the opportunity to explore the beaches with a local palaeontologist who knows what to look out for and who can tell you more about the fossils that are found there.

 

And if you'd like to experience the Fossil Festival for yourselves, put this date in your diaries: Saturday 3 and Sunday 4 May 2014. If this year is anything to go by, it will be another great weekend!

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Having arrived in Lyme Regis yesterday, greeted by sunshine and sweet salty sea air, we have been exploring the seashore and getting our bearings today.

 

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Lyme Regis

 

No visit to Lyme is complete without a trip to the beach to go fossil hunting!  Keeping an eye on the tides, we headed out first thing this morning to try our luck.  Museum scientist Ed Baker is a regualr visitor to the Jurassic Coast and showed us what to look for.  Rounded rocks can sometimes contain beautiful fossils...but need to be cracked open to reveal the animal or plant within.  This requires a special geological hammer (ordinary ones can shatter if used!) and a touch of experience/skill (cracking the rock open at the right angle is important).  Fortunately Ed has both of these things and showed us how it was done....

 

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Rounded rocks are hit along the edge using the blunt end of the hammer


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Several ammonites are revealed within the rock

 

But you can also find fossils without the need for hammers.  By looking carefully and sifting through the rocks on the beach, you never know what you might find.  Ammonite fossils are pretty common and vertebrae and other bones from fossil marine reptiles can be found by the keen eyed.

 

With our pockets bulging with our dicoveries and faces glowing from the sun and sea air, we headed back into town to start setting up the satellite equipment for this weekend's live links.  If you can't make it down to Lyme Regis, why not join our museum scientists in the Attenborough Studio at the Museum as we link to you live from the festival....

 

 

You can also follow us on Twitter @NatureLive

 

For more information about the Fossil Festival, visit www.fossilfestival.com

 

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Honorary member of the team Ed Baker helps Media Techs Tony and Eddie set up our satellite equipment

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The sun is shining, the bank holiday weekend is approaching, what better time to head down to the coast? But this is no regular seaside jaunt because this weekend Nature Live is joining scientists from the Museum, Plymouth University, the British Antarctic Survey and the National Oceanography Centre, Southampton to name but a few (! ) for the annual Fossil Festival in Lyme Regis. It's free, open to all and crammed full of exciting events and activities. 

 

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The coast at Lyme Regis

 

 

Nature Live will be linking live, via satellite, back to the studio in South Kensington, reporting on all the comings and goings at the festival, new fossil discoveries along the coast of Lyme Regis and where's the best place in town for a decent ice-cream (extensive sampling will be taking place throughout the weekend!)

 

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A seagull stole Natalie's (centre) ice-cream shortly after this photo was taken at Lyme Regis last year!

 

So, if you're free this bank holiday weekend, come and join us in Lyme Regis - more details about the festival can be found here - or join us in the Museum for the following events:

 

 

You can also follow us on Twitter @NatureLive

 

Now, it's time to track down some ammonites ...

 

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Phew, it's been a busy few weeks at the Museum!  With snow outside and schools on holiday, everyone was keen to visit the Museum and to mark the Easter holidays we decided to programme some suitably festive Nature Live events ... my favourite being Eggs-tinct! If you weren't able to see it in person, here are a few highlights:

 

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No egg event at the Museum is complete without reference to dinosaurs and Museum curator Lorna Steel brought along this beauty! A REAL dinosaur egg!

 

Equally, no egg event would be complete without the largest egg in the world ...

 

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No, this isn't some clever perspective, camera trickery - this really is the size of the largest kind of egg in the world (with Lorna's average sized hand above). This one belongs to an extinct Elephant Bird, a species that once lived in Madagascar. These birds were huge - at 3 m tall they were far larger than today's Ostriches - and consequently laid very, very big eggs. EGGs-traordinary!

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Hopping Mad

Posted by Charlotte - Nature Live host Mar 13, 2011

It's been a busy weekend of events....first Tadpoles on Saturday and then Dwarf Elephants on Sunday.  A curious combination of topics, but each equally fascinating!

 

Our Tadpole event was timed to tie-in with the first frog spawn starting to appear in our ponds.....which apparently it is, although warmer weather should help more appear.  Apparently (according to our amphibian curator Barry Clarke) frogs have been known to produce spawn as early as December some years, but hard frosts kill the eggs and it's not until the weather becomes milder that the tadpoles are able to start developing.  In fact, the warmer the weather, the quicker they devlop from tadpoles to adults.

 

Barry was a complete star as always and brought along lots of specimens from our zoology collections.

 

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Note the specimen in the centre of the bottom row.....this is a Midwife Toad.  They show great parental care (unlike our common frogs which lay their eggs and then leave them!)  The female Midwife Toad lays her eggs and the male then wraps them around his back legs.  He then carries them around with him (swimming and moving about seemingly unhindered) until the tadpoles are ready to emerge and swim off.  Because of this parental care, the eggs are far safer and have a greater chance of survival than if they were left unprotected.

 

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However, for the ultimate in parental care, go onto the BBC website and use their 'wildlife finder' to watch some incredible footage of Darwin's frog.  You won't believe your eyes    http://www.bbc.co.uk/nature/life/Darwin%27s_Frog#p004j5y9

 

As for the Dwarf Elephants today, well, they were certainly small!  Tori Herridge (a researcher in our Palaeontology Department) brought along some fossils from our collections....including lots of teeth.  The photo below shows the tooth of an extinct Straight-Tusked Elephant at the bottom and an extinct Dwarf Elephant tooth at the top of the photo.  Quite a difference in size!  The Straight-Tusked Elephant was one of the largest elephants ever to live, and could grow to as much as 4 metres tall.  In comparison, Dwarf Elephants were sometimes only 1 metre tall as adults!

 

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We'll be repeating Tori's Nature Live event later this month, at 2.30pm on Wednesday 30th March in the Attenborough Studio.  As always, the event is free and lasts for 30 minutes.  So come and join us if you can and discover more about these mysterious Dwarf Elephants.....

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Who doesn't love a good dinosaur event?!  Triceratops, T-Rex, Diplodocus, Stegosaurus....the list goes on.  But have you ever heard of Scelidosaurus, the topic of our event last Sunday??

 

I certainly hadn't until I met Palaeontology Curator Tim Ewin.  Scelidosaurus was the first whole dinosaur ever to be discovered (before that, only parts of dinosaurs had been found, and no-one had discovered any skulls)....and what's more, it was found right here in England, along the coast at Lyme Regis.

 

 

Scelidosaurus wasn't a massive dinosaur, diplodocus and the like were all ALOT bigger, but it had some fantastic armour plating which may have helped protect it from predators but also may have acted as a form of display, to deter opponents or attract a mate.

 

 

But what's so special about the Scelidosaur remains in Lyme Regis (which are continually being discovered as the cliffs slowly erode) is their quality.  The fossils have been brilliantly preserved and scientists are able to study the bodies of these animals in great detail, including their skin which remarkably has also been fossilised.  

 

 

So next time you're talking about your favourite dinosaur, spare a thought for the often (and wrongly) forgotten Scelidosaurus.  The first whole dinosaur ever to be discovered, found right here on our fair isle and with fossilised skin too - you don't get much better than that!

 

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Scelidosaurus is the dinosaur at the bottom of the picture.  Megalosaurus is at the top.

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Today's Nature Live event was a real crowd pleaser.  Almost as popular as a dinosaur event (!), we caught up with the curator of our Pterosaur collection, Lorna Steel. 

 

Lorna did a great job of enthusing about the myriad of Pterosaur species that once filled the skies.  With an incredible variety of shapes and sizes, these creatures were around during the time of the dinosaurs and were very successful until the mysterious extinction that caused their demise as well as that of the dinosaurs.

 

Pterosaurs were flying reptiles and ranged in size - some were as small as the your average garden bird, others had a 10 - 12 metre wingspan!

 

There are a range of images on the Museum website, showing what these impressive animals may have looked like.  My favourite is the Tapejara

 

 

Lorna's off to a conference on Pterosaurs in China soon, so hopefully she'll find out the very latest on Pterosaur research and be able to fill us in at her next event.  She's already on a mission to count how many bones are in an average Pterosaur skeleton and how fast they flew....

 

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Picture:  Pteranodon was a giant flying reptile - a pterosaur - a close relation of the dinosaur. They lived during the Cretaceous period aroun 85 to 75 million years ago. Illustration by Neave Parker.

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As part of our Future for Nature season (which has been running on Tuesdays and Thursdays for the past few months) last Thursday I hosted an event about how much oil is left.  Needless to say, it was very thought-provoking.  Andy Fleet, from the mineralogy department, used to work in the petroloeum industry.  He explained how oil is formed over millions of years and how it is found and extracted.  For further information, he suggested visitors have a look at the website of The Association for the Study of Peak Oil and Gas (ASPO) http://www.peakoil.net/  Here you'll discover the debate and discussion surrounding how much oil is left and whether we have reached a peak in oil production....or not.  To give you an idea of the varying estimates, have a look at the graph below.  This shows various predictions for when we will reach peak oil production, the majority of which suggest we have already reached the peak or will do so in the next ten years.  There are a few estimates that suggest a continuing increase in oil production, but whatever the conclusion, one thing is for sure.....at some point, whether today or tomorrow, oil production will decline and we need to be ready with an alternative. 

 

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Graph sourced from The Oil Drum http://www.theoildrum.com/story/2006/11/13/225447/79