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Hello discuss fossils,

I’ve been on the lookout and collecting ammonite fragments along a stream in Cambridgeshire for a little while (trying to find a nice specimen) and came across this bone. Formation is Kimmeridge Clay for this area.

Could you give me guidance on understanding the difference between a modern bone eg bone from a cow and a fossil. 

If it is a fossil, could you help identify it and provide a good website to help me educate myself on identifying bones.

thanks all

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Barrow Museum
The bone you have found is I think from a a large mammal and almost certainly recent or sub-recent (maybe Pleistocene).  It isn't Jurassic at any rate.

How can we tell?  The first consideration is that during the Late Jurassic, when the Kimmeridge Clay was being deposited, there were no mammals to speak of (just a few tiny primitive forms of extreme rarity).  So you should expect to find bones of fish and marine reptiles, like Ichthyosaurs and Plesiosaurs/Pliosaurs.  The bones of these which are most often found are the vertebral centra (the disk bits) and the propodials (the humerus and femur).  As a rule of thumb, in Jurassic formations of the UK, these will always be heavy, completely mineralised and of distinctive shape - you can look these up on the internet.  I should not be in the least surprised if your searches in stream beds yields these sooner or later.  Land-living reptiles, like dinosaurs have been found in these marine clays, but are extremely rare as their preservation there would have involved a carcass floating out from a river, into the sea before sinking and being buried.

You might also find Ice Age mammal bones in your area.  These are much more recent and in some cases can be confused with modern animal bones that may have originated as someone's dinner, as most Pleistocene mammals have living representatives today (though many of these are no longer part of the British native fauna).  The bone you illustrate looks to me like the leg bone of a juvenile cow, sheep or small horse. Again, although it is not a hard and fast rule, I find I can distinguish modern from more ancient, Ice Age bone by whether or not they have lost their collagen.  A modern-ish bone, when touched against a slightly moist lip, will not attach itself.  An ancient bone, with no collagen left, is porous and provided it is dry, you will detect it sticking to your lip slightly. There are exceptions, particularly where the bone has actually lost its porosity due to mineralisation, but this would be rare with Ice-age material.

The staining indicates that it has probably been lying buried for a long time.  Try the lip-stick test and report back.
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Hi Barrow Museum,

Thanks for the reply and info. I thought it would be along those lines. Thanks for the info on the common finds for fossilised bones, I know what to look out for now.

I’m not going to lie, sticking a lip on this thing is not something I look forward to do doing! Only problem is I want to work out how old it is and what it is, now that I’ve found it.I can’t get over my curiosity. I’ve asked a archaeologist within my business to give some help, but if I get nowhere than I will consider the lip test and report back. 

Thanks for all the tips guys, it’s helps us newbies out a lot

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Hi Barrow Museum 

I left it to dry and put a wet lip on it (to be honest I have been thinking you were pulling my leg 😉 but I’ve gone for it anyways) and it did attach itself to my lip, so it passes the test. Question is, what do I do with it now to find out more?
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Barrow Museum
You have established that it is pretty old and all the organic matter has departed.  Someone out there who has knowledge of recent mammal skeletal anatomy should be able to identify it, but as the distal and proximal joint surfaces have dropped off it might be a little more difficult (I think because it was a young individual and the epiphyses have dropped off where the growing cartilage had not yet fused).

If you want to have a go yourself, have a look at this excellent website from the Natural History Museum, which helps a great deal in mammalian bone identification

If by some happy coincidence, it is from a Pleistocene mammal, you may need to apply some protection to prevent it from splitting and the cortex flaking off.  A standard method is immersion in a milky suspension of PVA  glue in distilled water.  Soak the bone for more than a week (longer the better) and then dry it out extremely slowly.  This should keep it together. 

It may not be of particular geological/archaeological interest, unless its context can be firmly established.  But good luck with its conservation.
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