Lyme Regis Museum - Virtual Fossil Walk

[Music] hi I'm patty how I'm the geologist at Lyme Regis Museum and today we're going to be looking at a few fossils here some things you can find in this area the first thing I have to say though is it's probably the most important that's a little bit about safety and behind me we have the cliffs part of the blue liars and these rocks are around 200 million years old the main thing about them is they are extremely soft and crumbly Rock Falls can happen at any time without any prior warning whatsoever so the first thing I'm going to say really is to keep away from the cliff face itself most fossils we find are just lying around on the beach and you don't really need to be up the cliff face it is extremely dangerous you you okay before we actually look for any fossils at all there are a couple of other important things that we need to just talk about which is kit equipment you don't need a lot of equipment but some of it is absolutely vital so first and foremost sturdy Footwear this is a nearly brand-new pair of walking boots they won't last yeah if we're out here all the time they won't last very long I'll get through a pair of these in a year with no problems at all but sturdy Footwear sensible clothes just for whatever the weather is so really hot sunny day like this so I'm in a t-shirt in the wind so of course you might want a raincoat or something warmer have fleece something like that and the most important piece of clothing is a hat I always bring a hat I never go falling without a hat and always wear a peaked cap for several reasons firstly the peak will keep the rain or the Sun out of your eyes wearing a hat also means you don't get sunburned on your head I've used my hat to bail water out of rock pools to get up fossils I've wrapped fossils in my hat so it's a really really useful and versatile piece of equipment ok another piece of vital equipment is this the local tide timetable cost a couple of pounds for a year's worth of tide information and that can save your life so absolutely vital you don't want to have to call out the lifeboats or any other organization the Coast Guard they'll be not very happy with you and will be extremely embarrassing the next thing water it's easy to get dehydrated out here on the beach so water is essential and I always bring water I don't bring orange juice or anything else sometimes I'll use the contents of my water container to wash fossils go wash the mud off so I can see them better you don't wanna do that with orange juice make sure makes your fossils all sticky and horrid but water absolutely essential on a more Fawcett II theme the next piece of kit people always assume that you should use a hammer I do bring a hammer this is a two-pound geological hammer if you use an ordinary hammer a claw hammer or a ball Pein hammer these are not suitable for hitting hard rocks and they're the wrong shape so you really do want the genuine article there's some weighs about a kilo if you're going to be hammering you will need these as well.i protection so just a little pair of safety glasses you can pick these up from builders merchants places like that usually perhaps six or seven pounds for a decent pair these ones also the protection comes around the side so nothing's going to get you into the side of your eye if you use big old chemistry lab goggles what you can find is for you then hammering they can tend to steam up and yeah you get a bit sweaty while you're hammering and then they're and they're not so good okay yeah something else you should bring with you anywhere if you're out in the open slippery rocks sharp rocks see anything like that is a small first aid kit or at least some plasters certainly when when you hit a lot of the rocks that we hit they can be hard in the splintering it's not unusual to get bits going into your hand and it costs a good go into your eyes or other parts of your body so those are essential and the last piece of kit may not seem obvious but it's this and this is a case which has my iPhone inside I have lost two phones to to the rain already I'm not going to come out here with a 600-pound phone certainly and yeah so one of these little waterproof cases which also float can be very very useful another piece of kit which is absolutely essential and people forget about all the time is a bag so this is my rucksack it's a bit of a mess and it's only two years old to you this environment really is tough on you on your kit but a sturdy bag it doesn't have to be a rucksack even a carrier bag something sooner or later you're going to find something which doesn't just fit in your pocket so you really do want something to carry carry your stuff or any food or drink that you might want to bring as well okay so now I'm going to tell you a bit about some of the fossils you can find and most of the things that we're going to look at are things you can find just lying around you don't need as we said earlier to be up at the cliff face that can you know can be quite dangerous and you can find perfectly good fossils just lying in among the stones on the beach so I'm gonna start with the bones that we find and this is the most common bone of all that's a vertebra piece of back bone and this one is from an ichthyosaur so a creature that looked a little bit like this this one shows a number of features so the two little pads on the top little lumps where the ridge would that would detach on each side but obviously when we find some of these things they've been on the beach for some time and I have another example here which is a little different so this one I think that's probably the top but I'm not sure I can't really see any rip attachments but it has the main things we look for it's more or less like the usually more or less circular and they have this dip in each side and this one even though it's really worn you can still see a little bit of that dip on each side that's what gives it away as being a piece of backbone from an ichthyosaur now let me find vertebrae they're not always on their own so sometimes you can find several join together what I have here are two quite good sized throw debris still joined together and again these were lying on the beach just like this so this one has an interesting feature so you can see the dip on each side that all ichthyosaur vertebrae have on this end but this end there's no dip and that's because this the dip here is actually filled with calcite crystals those are little crystals quite important in this area when we kept bones fossilized together we almost always find calcite crystals growing in between so if I were to pull these apart there would be crystals in the middle and the fact there are crystals on this end instead of stone that tells me that when these are fossilized other bones other vertebrae were attached on this end about five minutes after I found these a friend of mine just a few meters away found another and this one has crystal on both sides and it's obviously the same size and preservation in the same area and so we compared them and there they go they fit together but we still have crystal on this end and that tells me there must have been at least one other vertebra attached to these two weeks later a friend of mine came into my workshop and showed me this nice ichthyosaur vertebra calcite crystal on the other side and we put them together and they all fit together exactly so these are all from the same animal the calcite crystal actually locks them in place so that yeah so these are definitely together in life like this but no more no more calcite so these four vertebrae have become separated from the rest of the animal it's a little icky Thea sort of stake if you like it's just become detached and these are the vertebrae from it and again all of those just lying around okay so the first row debris I showed you where a normal-sized yet maybe an inch across you know to three centimeters the next ones I showed you a slightly bigger but if you're really lucky you can find quite big vertebrae bigger animals are much less common so yeah most vertebrae like say this kind of size this is much bigger but much rarer you wouldn't expect to find one of these every day if I'm here on the beach a small vertebra I would expect to see pretty much every day but one like this this size I might see maybe two or three a year like this not some really good condition and that was really nice find now we find other bones from other animals it's not just ichthyosaurs that we find here although they were the most common reptiles the next most common reptile is this a plesiosaur so we see living reptile small heads long neck big body for big flippers and many people of course believe the Loch Ness monster to be surviving plesiosaur there are all sorts of reasons why that may not be the case I'm going to find bones from them as well and here I have a plesiosaur vertebra and it has a few a few different features from those of the theater these are obviously different from ichthyosaur vertebra I can show you the features that tell us the or show us those differences so the ichthyosaur vertebra it's got this dip in each side and it's quite short the length is about half of the width of the vertebra with Pisa sores the proportions are different so if we look at this one you see the diameter is about the same we see the length of the previous tall vertebra is much greater it's about twice as long as the Ixia saw vertebra also it doesn't have such a big dip on each end it's a lot flatter and it's those features that enable us to tell that's that's from a different creature please is all vertebrae a much less common than those of ichthyosaurs so for every 30 or 40 ichthyosaur vertebrae you find you'll probably only find one of these again we do find more than one sometimes I want to have here is a pretty much a pebble if you look carefully you can see something on this side so what we have here is parts of three please the it's all vertebrae so complete one here in the middle then because here's a junction here in Junction here then parts of two other worn vertebrae on each side something else which is of interest when we see fossils they're often easier to see when they're wet so I'm just going to make these wet and you will hopefully see the difference and you can probably now see that it's really standing out there's a lot more contrast easier to see so yeah don't be a fair-weather foster if it's raining that's a good time to go okay and the next what I'm going to talk about is something a little unusual and it's this now that probably just looks like any old stone to most of you out there but it's actually quite an interesting fossil and this is a copper light and that's the name we use for fossil poo so that's a big piece of fossil and again was found just lying around on the beach okay so this yeah this is the copper light a big brown amorphous blob and these are really really difficult to spot they're the hardest thing to learn to spot no two of these ever look the same this one's quite plain and relatively boring but sometimes we find ones like this so we can see lots of lots of fish gals all these black shiny pieces and sometimes you can identify the fish from the scales it's often harder to identify the animal to produce the copper light in the first place this one the other one these are probably from it fears they were the most common reptiles here so it's just most likely we do find other ones however this which can give us more of a clue as to the animal which produced them so this one you can hopefully see has a little series of grooves running around here it has a spiral structure that tells us it's almost certainly from a shark the Sharks have spiral valves in their intestines which create that shape this one also has fish scales and some of the other things that we've seen in the other one now you may have come crossed expression you can't polish a turd yes you can this is a piece of fossil proof and I had a good friend of mine this is the unpolished surface had a good friend of mine polish it and this is the result I use this as a paperweight on my desk at home and it really is a wonderful wonderful tactile object for a piece of poo Victorian ladies used to read of stuff as jewelry when it was polished without knowing exactly what it was but yeah wonderful wonderful material okay now I'm going to talk to you about some of the invertebrate fossils we find so animals without backbones or skeletons all the things I've shown you so far have been from the early Jurassic period so around 200 million years old we do have some younger rocks here as well so you can probably see at the top of the cliff a sandy colored layer this is a Cretaceous rock it's called green sand that's about 112 114 million years old and above that they used to be chalk all that's all gone all eroded from the side of lime but we still have chalk to the west and what we find in the chalk is Flint and occasionally in those Finn's we find these and this is a sea urchin this one's called my Craster heads one of the harder chins and you can hopefully see it's got five little rays on the top that form a flower like pattern on the underside there's little dents just in here that's animals mouth around here another little dent and that's the other end this one's in pretty good condition and again was found just lying around on the beach just like this and again when they're on the beach for some time they will get worn and broken up and I have a much how much worse specimen here you can still make out some of the features some of the little rays and the basic shape the mouth here but not in great condition but you know when things are on the beach sometime this is what's what's going to happen to them okay the next fossil another reasonably common fossil and it's this this is an oyster it's called weifare are cuota but it has more common name for about 200 years people have referred to these as the devil's toenail for obvious reasons that one's in fairly good shape you see a lot of the growth lines in pretty good condition but once these get onto the beach they don't last very long the sharp edge is the growth lines will get worn away quite quickly so a lot of once we find a more like this you can see that this has much less detail some of this edges broken away hardly any growth lines to see there okay the the next course I'm going to talk about and they're actually animals but they looked a little bit like plants and they're called crinoids or sea lilies the most common pieces we find are these this is a section of the stem the stem would be up to perhaps a meter in length and you can hopefully see that the the stem has a five pointed star shaped cross-section so these are quite easy to recognize little bits like this fairly common in among the small stones on the beach this one's quite a nice piece we often find little little pieces which are we're not so good but still quite recognizable you'll see the little parallel lines running running across there it's that kind of symmetry that makes it stand out from everything else that's on the beach at the top of the stem you have the main body or calyx it's quite small in this species it's called Penta core 90s and that had a mouth in the center around the mouth or five arms those arms had feathery extensions that open the arms out into water currents to filter food they'd pass the food to the mouth in the center this piece shows some of the arms from the top of the the cry noise they probably would have culture about here somewhere so missing some of this again this piece has been on the beach for a little while that's quite nice because it shows pretty much a complete head we do find a lot of pieces though which are less impressive so this piece you see a couple of pieces of stem on one side on the other side may be difficult to see but there are lots and lots of little feathery arms from the top of a pride and this is solid cry noid there's no stone here at all it's just entirely made of fossil and again that piece just lying around the next fossils now these are very common fossils fact the only thing that's a you know film on the beach I'd guarantee to find every single day they are bullet shaped objects made of calcite crystal so this one remains a fossil squid or a squid like animal and it's a creature that looked a little bit like this this creature is called a belemnite and this part is called the guard it's a bit like the shell of a cuttlefish so go inside the animal at the back something like that the rest animal's body was soft we don't usually find that preserved as a fossil but occasionally the soft parts are preserved that's how we know roughly what they look like a complete guard will have a point at one end and a cavity at the other and the cavity is often filled in with a bit of mud stone or bit of limestone but these are also made a calcite crystal these get smashed up quite easily most bits we see we'll just be little tubes little cylinders like that or the broken off pointed ends of bigger specimens okay the last first I'm going to talk about it's probably the most iconic fossil it's the one that pretty much everyone will recognize and it's this this is an ammonite so kevlar pods related to squid and octopus and cuttlefish usually having a spiral shell like this and this is also just the models who got soft parts we don't normally in fact the soft parts have never been found for ammonites so a spiral shell the chambers in the center of the shell filled with a mixture of gas and water this would allow the animal to float around now we can find ammonites flying around but most of the time what you see are a little squashed ammonites like this so these are in fairly soft rocks and the rock hasn't protected the ammonites so they've been crushed but sometimes we find other much harder rocks like this if you know they're kind of rock to look at you can split them open and if you're really lucky you'll have something like this inside so that's quite a nice I'm a tight one called Zephyr Osiris in pretty good condition that's bigger than most that we find most of a lot smaller and it doesn't have to be a big piece of rock so this is a small fragment of rock I found I recognized it as the right type of rock and I could see a little white mark on here and that's the cross-section of an ammonite so I knew it was a stone that could contain other ammonites and even though it's so small I broke it open they can hopefully see a lovely crystal laminar inside out of interest the brown material here is the shell of the ammonite that comes away with the with the stone the white material here is calcite crystal which has grown inside the ammonites empty shell the other thing we do find are metal ammonites and people often think these are fake or bits of jewelry that the people have dropped so what I have here is a little ammonite made of iron pyrite or fool's gold it's a compound of iron and sulfur and it's filled in the empty shell or forms a natural cast and these ones we can find just lying around now when we're out looking for fossils it's worth remembering that the tide roughly sorts things into sizes if you're looking for something that's maybe 2 or 3 centimeters across then you need to look in Hmong stones of that kind of size you may or may not have noticed in that last few seconds of film that there was a fossil in that shot and it's here this is an ichthyosaur vertebra looks like one from the tail it's in fairly good condition and about average size okay and I have one more thing to show you just to illustrate you have the quality of something so you can find just lying around I found this probably about 15 or 18 years ago something like that and it was just lying on the beach so this is part of an ichthyosaur jaw so you can see teeth all the way down here it's 3d as well so we have teeth on the other side this is the nostril so the skull would come up here to have a big eye about here the end of the snout down here somewhere and again this was just lying in the sand just a little a little bit of it poking out but yeah I could see enough to know exactly what that was going to be this is a more unusual find most days most years you probably won't find something like this just lying around but does illustrate what can be there to be found on a very very good day [Music]

Channel: Lyme Regis Museum

Views: 18,639

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Id: ax4GM9SKCaQ

Length: 23min 40sec (1420 seconds)

Published: Fri Jun 19 2020