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Last night, we arrived back at the hut just before dark and ate a dinner of soup (chicken) and rice (sin bean). Over dinner we learnt that, in our absence, Holger and Jo had a productive time (more on that below) and it was nice to be all back together again.

 

Today I stayed at the hut (checking everything was working for our next live-video-link back to the Museum which will be happening just as this is published) so I had the chance to chat to one of the porters assisting our trip.

 

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(From left to right) Leandro Vargas Astavia and Greyner Vargas Astavia
Daniel Lezcano Arguello and Carlos Godinez Cardenas

 

Daniel Lezcano Arguello started off by apologising for laughing at my new nickname - which has morphed from Yeti via Crouchy (as in Peter, the lanky, robot-dancing footballer) to Pie-Grande. I pointed out that Yeti and Pie-Grande are absolutely fine but Crouchy has most definitely got to go - I am an Arsenal FC fan!

 

He told me about his life when he is not working as a guide or porter. He is a farmer and has 5 hectares near the entrance to Amistad National Park where he grows coffee and bananas and keeps pigs and cows. The coffee he sells to a large Costa Rican company although he keeps a bit back for personal use as he prefers to know what is in his morning cuppa. The bananas are used to feed the cows and pigs.

 

The cows are for milk and he makes cheese, and the pigs are for meat. He also grows some vegetables and we swapped allotment stories although he seemed pretty unconvinced it was possible to grow anything in British temperatures.

 

He said he is typical of the porters in that they all farm when not guiding people through the park. This trip (like most field work, I imagine) would be impossible without the help of the porters.

 

They prepare trails and camps and ferry specimens and food to and from the field, and they carry extraordinary amounts and move incredibly quickly through the forest. This is the head porter and our guide Carlos.

 

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Head porter Carlos making his work look easy while I struggle to keep up (hence the blurry photo!)

 

He is carrying a backpack, a few litres of water, camping equipment for 4 and - if that wasn’t enough already - a shovel.

 

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Leandro taking a breather

 

I am in awe of their strength and athletic ability at this altitude and their commitment to our trip. They have an invaluable knowledge of the forest and are key in helping us find interesting sites and species. Also, they are vital for the conservation of the park so we are doubly thankful for what they do.

 

Species of the day today goes to Holger - the result of 2 hours hard work, blood, sweat and tears!

 

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Holger found three different stream lichens with a high likelihood that they may be new for Costa Rica and maybe even new to science.

 

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This lichen is a representative of the family Lichinacae and fresh water species of this family are commonly found in Nordic countries.

 

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Holger didn’t expect to find something like this here and all of the lichens Holger has found reflect a climate far, far colder than would have been expected - something we can vouch for during the long cold nights!

 

This is why lichens are so important in that that they tell us so much about our environment. Sadly, no video today – I hope to get back to business tomorrow.

 

(Just a quick reminder that Alex is also writing his own blog about our trip and you can read it here and that our next live-video-links with the Museum are at 12.30 and 14.30 on Saturday 18 February)

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You only have to browse through the Fossils and rocks forum to see how many of the suspected fossils put on there turn out to be something completely different! Fossil eggs, bones, turtles, ferns, footprints, you name it, natural rock and mineral processes can mimic it. We call these natural rock and mineral specimens that resemble or are mistaken for fossils "pseudofossils". This post doesn't seek to go through the most common look-a-likes, but if you google "pseudofossil" you will find many excellent guides out there.

 

This post is just some of my personal favourites from the last year. Fun and amazingly co-incidental pseudofossils are one of my favourite parts of my job in Earth Sciences identification.

 

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"Fossil bird head"

 

It's got everything - neck, beak, even an eye. But this shape is created by the growth of a mineral upon the rock surface.

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"Fossil shark"

 

This shark shape, silhouetted in white against the dark background, would have me swimming for my life if I saw the silhouette peaking out of the sea. But it is just a chance area of cleaner white Chalk against a backdrop of Chalk discoloured by dirt and moss.

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"Fossil fish"

 

I can see what they mean, it looks like a guppy with a long flowing tail and fin. But this is a type of the rock flint known as banded flint. Banded flints form a series of roughly parallel lines such as this, which can create all sorts of misleading shapes. The cause is still not fully understood but the movement of water and silica through the flint is thought to be involved.

 

The rock flint can mimic any kind of fossil you can think of - bones, eggs, whole heads and bodies, you name it. Look out for a blog all about the wonders of flint coming soon!

 

2011-0058 dinosaur head pseudofossil 001.jpg"Fossil dinosaur head"

 

If this were a dinosaur, I can even see what kind it would be - one of the duck-billed hadrosaurs I reckon. Sadly, this is just the shape of the lump of rock, that had probably been exaggerated by weathering.

 

 

While writing this I've realised that these pseudofossils do have something in common after all. They all demonstrates one of the key things to appreciate when looking for fossils: don't look for the overall shape of an animal. This is because the soft parts of animals like muscle and skin only fossilise very rarely and in unusual conditions. You can assume you won't come across soft part preservation without knowing what to look for and where to look. To find fossils, look for the hard parts such as bones and shells, and bear in mind these are most often broken, mixed up and/or isolated.

 

Although we can say what these aren't, the hardest question to answer is, so why did the rock or mineral form or weather into exactly that shape? There are millions of rocks out there and so even if such coincidental resemblences are rare, there will still be plenty of pseudofossils. And of course those are the rocks that are going to catch your eye and get picked up.

 

So what should you look for? This page on our website has some good information and links for fossil hunting advice. And of course we will be happy to see whatever you find, whether rock, mineral or uncannily-vegetable-shaped-rock on the rock and Fossil forum here.

 

Happy fossil - and pseudofossil - hunting!

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How to identify an elephant tooth


A beginner's guide to how we identify a surprisingly common enquiry: mammoth and elephant teeth.

 

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Left: This tooth was a family heirloom brought in for ID this week. Many elephant and mammoth teeth that are brought in for ID are heirlooms that have been knocking about the house for a couple of generations. This is an Asian elephant tooth. It is a molar, so it's a grinding tooth.

 

Below: Grinding surface of Asian elephant tooth (left) and African elephant tooth (right) in the NHM Mammal gallery. The African elephant tooth has a more diamond shaped pattern to the grinding surface

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And the elephants themselves in the Mammal gallery - African (top) and Asian (below). Asian elephants are smaller than African elephants and their teeth are smaller on average too.

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Below. On the left, a mammoth tooth. On the right, a modern Asian elephant tooth.

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Left: Mammoth tooth. This was dredged up by a fisherman from the North sea and brought to us for ID. Mammoth teeth have a similar grinding to the Asian elephant, and look different to the grinding surface of the African elephant. And mammoths are indeed more closely related to Asian elephants than African elephants!

 

 

 

 

 

 

 

 

 

 

Mammoth and elephant teeth can be very fragile and tend to crack downwards as you can see here. This can leave isolated plates instead of the whole tooth.

 

Now you can identify elephant and mammoth teeth!

 

Visit out Twitter page at http://twitter.com/NHM_id to see the finds we get in every day