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UKAFH field trip to Folkestone Sunday 6th October 2019

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Another week another hunt! Great stuff! This week we were visiting the late Cretaceous deposits of the Gault Clay and Lower Greensands at Folkestone, Kent. The geology at Folkestone is Albian age, between 90 and 112 million years old. Although there are chalk exposures east of Folkestone, our focus today was west from the beach entrance at the Warren heading towards Copt Point.

We assembled in a quiet residential street (I think the locals have got used to our occasional assemblies of yellow jacketed, hard had wearing groups!) and Sam gave a superb talk with some great show and tell fossils. The rocks at Folkestone we’re formed in a shallow marine environment so the fossils include molluscs such as ammonites, belemnites snd bivalves as well as corals, sharks and other fish, urchins, turtle and occasional marine reptile remains. However the seasonal dryness in the locality is evidenced by scarce dinosaur footprints. Many fossils are exceptionally preserved, retaining original shell preservation, due to the soft and highly anaerobic clay which preserves aragonite and calcite shells in beautiful, iridescent colour. Chris, our leader on the day, briefed the group on the locality and a couple of health and safety messages and we headed down to the beach carefully, then heading West from the chalk to what we hoped would be much exposed clay.

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We totally beat the weather forecast, with many of us stripping off the full waterproofs for much of the excursion, and got away with only a couple of showers. Unfortunately we could not contend with the abundance of sand covering a lot of the clay so a chunk of the areas we are used to hunting were covered. This did not mean it was an unproductive hunt though and more than I was expecting was found! Yay!

The first fossils encountered were from the freshly slipped clay. The colourful shells of the bivalves within were evident but were too fragile to collect and we also found an unusual number of equally fragile heart-shaped urchins.

A very large and exceptionally well preserved shark tooth was found by Jo and Isabel and Peter Bines continued his hot streak, finding a little tooth that would have gone unfound without his persistent sieving efforts as well as part of a chimaeroid fish tooth palate which has a distinctive spotted texture and can be found in both the Gault clay and Greensand.

Suzanne, a first time guest was pleased to find some iridescent ammonite sections and see the beautiful but fragile bivalves which look gorgeous on the beach but have a short shelf life once exposed. Meanwhile Louie Fleckley found some beautiful complete ammonites!

Other finds on the day included crinoid stems, a fish vertebra, a solitary coral, many ammonites and ammonite fragments including sections of heteromorph (irregular/uncoiled) ammonites which are unusual but quite common at Folkestone and yet another great find from hawk-eyed Peter who found a beautiful small crab carapace.

Everyone had a fun time and it was absolutely lovely to wander up to Sam and hear that our youngest guest of the day Louie wanted to tell her before he went home that he had a great time and thought we were all lovely! Thanks for the great feedback and that is exactly why we do this. We love to encourage and inspire and share our love for fossils!

Roll on the next hunt!

Chris Tait

 

UKAFH field trip to Doniford Bay, Somerset on 15th September 2019

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IMG_6769On 15th September 21 UKAFH members set out to explore the geology and fossils of Doniford Bay in Somerset.  Our group assembled at Doniford Farm Park with their kind permission, since the nearby public car park was closed at the start of the year. This allowed us to park and gather easily as well as providing a wonderful opportunity to purchase delicious lunches and a variety of local produce and wares as well as meeting the farm animals!

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In the glorious sunshine of a late September heatwave, we walked as a group to the nearby beach access and descended to the bay.  Sam set off to check the terrain and rock exposures on the beach and Aidan, the group leader for today’s event, provided some information to the group on the geology of the area and what the group might expect to find.  Directing our gaze to the distant cliffs in the direction of Watchet, Aidan explained that the red layers which were clearly visible displayed a history of interchanging desert and aquatic conditions, with water encroaching on the landmass then retreating to give way to desert conditions.  These varying states, occurring as Pangaea broke up and the Triassic period came to an end, finally gave way to full inundation by the ocean as the Jurassic period commenced.  The change in condition brought marine life to the area which leaves its record in the rocks beneath and around us in this location.

The rocks at Doniford Bay represent the very earliest part of the Jurassic period beginning 201 million years ago.  The most abundantly evident fossil is the ammonite Psiloceras planorbis, which is a zone fossil, which means it is recognised as being the defining biological marker for the start of the Hettangian stage 201.3 ± 0.2 million years ago, the earliest stage of the Jurassic period. All ammonites with the exception of the genus Psiloceras went extinct at the end of the Triassic so all Jurassic and Cretaceous ammonites are descendants of this genus.

Aidan continued to explain that the other ammonites we were likely to see demonstrate the evolution of this ammonite as it adapted and evolved to different niches of the newly opened up marine environment following the mass extincions of the end Triassic.  Firstly we will notice Caloceras johnstoni, which, like Psiloceras planorbis is always crushed flat but maintains aragonite (mother-of-pearl) shell preservation which often demonstrates spectacular rainbow iridescence but which evolved a ribbed shell which would have afforded advantages, possibly affecting buoyancy and swim control or resistance to predation or other damage.  This was succeeded by larger and more ribbed species like Arnioceras and Coroniceras which we hoped to see in situ in the wave-cut shale platforms.

The post-extinction sea quickly refilled with new life and Aidan informed the group that alongside the abundant ammonites we could also hope to find fishes, marine reptiles such as ichthyosaurs and plesiosaurs and plant remains.

We headed off as a group towards an area of loose rocks on the foreshore where we knew ammonites could be commonly found. Aidan pointed out some examples that were clearly visible and demonstrates how best to split the fragile shales, reminding group members to be safe using goggles and ensuring others were not close and vulnerable to flying chippings. He added that the delicate ammonites benefitted from preservation to bring out their colours and prevent deterioration and shared a tip that a smear of lemon juice was often effective in helping bring out the colour. Finally Aidan reminded members that they should only collect a few examples as no-one needs many identical specimens and there should be plenty left for others.

The group dispersed over the pebbly area and were quickly finding examples of Psiloceras and some Caloceras ammonites as well as some fragments of 3D ammonite. Chris Tait found a beautifully preserved example of Brachyphyllum, a cone- bearing plant which is known from the late Carboniferous to the Cretaceous.

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Brachyphyllum specimen found by Chris Tait

After the group searched the loose foreshore pebbles Aidan took the group to the ledges of shale along the beach where we could observe the later, larger ammonites like Arnioceras and Coroniceras. The site is SSSI so hammering if in-situ rocks is mot permitted and these specimens cannot be extracted but we were all able to view, photograph and enjoy the many beautiful examples visible on the rock surfaces.

We were fortunate to observe, on close inspection, a small fossilised fish exposed in the rocks and one lucky group member found a small ichthyosaur vertebra. Also visible were crinoid ossicles and sea urchin spines.

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Fish found by Aidan Philpott
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Small ichthyosaur vertebra found by Deborah

As we returned to the slipway to leave the beach accompanied by the sound of the steam train whistles there was still a surprise yet to come – a beautiful, unusually preferved brachiopod found by Jonah.

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UKAFH would like to thank Doniford Farm Park for allowing us to park for the duration of our excursion.  Your pasties and pies make delicious lunches and we wish we could have stayed for the delicious looking carvery!

We hope everyone had an enjoyable day at Doniford and we hope to see you all again on future field trips.

UKAFH field trip to Smokejacks pit, Sunday 12th May 2019

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On a comfortably warm and dry Sunday 12th May UKAFH was privileged to gain access to internationally renowned Smokejacks quarry – a large clay pit operated by Weinerberger located close to Walliswood in Surrey. The pit is famous for the near complete dinosaur specimens that have been discovered there, including Iguanodonts and the first discovery of the spinosaurid Baryonyx in 1983 by amateur fossil hunter Bill Walker. Baryonyx and many other specimens from Smokejacks can be seen in the dinosaur hall of the Natural History Museum in London.

The pit cuts through a section of the Weald Clay member of the Wealden group, dating from the Barremian stage of the Cretaceous period about 130-125 million years ago. During this period England was located in the mid-latitudes and experienced a highly variable climate of alternating searingly hot dry seasons with forest fires and baked ground and stormy wet seasons with flash floods which created lakes in a floodplain environment. The resultant ecosystem was highly diverse, supporting a vast number of aquatic and land-dwelling organisms, from tiny creatures like concostracods and multitudinous insects to large herbivores and predators like Baryonyx and Iguanodonts.

A great attraction of Smokejacks pit is the enormous diversity of fossils to be found here.  Whether specialist or generalist, there are spectacular fossils to be found if you have the patience, work ethic and eye to locate them.  There are beautifully preserved insects and the early flowering plant Bevhalstia in fine siltstones, concostracods (shrimp-like shelled creatures), abundant plant material, fish scales, teeth and death assemblages, as well as crocodile, pterosaur and dinosaur remains which can be unearthed here with a good eye and a bit of luck.

Our guides for the day were Weald Clay expert and PalAss English Wealden Fossils author Peter Austen and his wife Joyce and local Smokejacks regular Mike Webster, who has discovered a number of previously unknown insects at Smokejacks. Peter provided us with a fantastic, in depth presentation on the Weald Clay and showed us some fine examples of what could be found in the pit, as well as supplying a number of handouts describing the pit and the fossil discoveries made, illustrating the pit’s stratigraphy and providing drawn examples of some of the insect types commonly found. Peter’s roadshow introduced us to the diversity of insects for which the pit is known and covered in detail the discovery of Baryonyx and also a juvenile Iguanodont which was found together with Baryonyx teeth, suggesting predation or scavenging, which was later recognised as Mantellisaurus atherfiedensis.  Smokejacks is also known for a very rare, early flowering plant called Bevhalstia Pebja.  We also saw articulated fish death assemblages, an arthropod trackway, gastroliths (the stomach stones swallowed by dinosaurs to aid digestion), plant remains and the well-known concostracans, small shrimp-like creatures which bear superficial similarity to bivalves.

We walked as a group to the pit head, from where UKAFH leader Sam was able to point out the stratigraphical layers and indicate where people might start hunting depending on what they might hope to find.

Some attendees began by walking the slopes in search of any fossils which had been brought to the surface by recent erosion.  This is often fruitful and has yielded dinosaur bones and fish teeth and scales on previous occasions.  Others chose to work the “dinosaur” plant debris bed towards the top of the quarry; a rich seam of carbon and lignite where plants have been fossilised and which has been found to often also contain dinosaur remains. Those in pursuit of insect remains headed towards the bottom of the quarry to find and split the finely grained stones in which their remains are preserved.

Soon after our arrival; finds began to appear.  Mark Goble and Sam Caethoven returned to a small siltstone exposure in the lower part of the quarry which had proved fruitful on a previous visit and were soon finding blocks containing a very rich layer of jumbled fish bones which is overlain by insect remains. Some of the fish remains are articulated and very well preserved.  Mike Webster also began to find some fine insect specimens. Many of the group came a long to see what was coming out of the insect bed and went on to find their own insects after seeing examples of the right stone and how and where to split it.

The area of the quarry we had access to has not been worked for several months and has been well-visited over that time, with little inclement weather to erode the surfaces.  Consequently finds were less common than in the past, however no-one went home empty handed.  Those digging into the plant debris bed like Andrew Marsh found some beautifully preserved seeds and leaves and surface hunters and diggers with keen eyes like Vicky Lane found Scheenstia fish scales and teeth.  Adam Ward was rewarded for his digging efforts with the day’s only dinosaur bone find and Peter Waring did very well, finding part of a hybodont shark fin spine.

It is uncommon to have access to a working quarry where the extraordinary, fossil-filled stratigraphy of the Wealden clay can be observed and explored in a way that is impossible in a coastal cliff setting and everyone enjoyed the experience.

UKAFH would like to thank Peter and Joyce Austin, Mike Webster and Weinerberger for allowing us to visit and making the outing successful, enjoyable and informative!

Sam Caethoven

UKAFH field trip to Cross hands quarry, Warwickshire on 21st October 2018

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We were blessed with a warm sunny day on the 21st October to Cross Hands Quarry which is located on private land owned by Mr Newman. Mr Newman had kindly created a couple of fresh spoil heaps especially for our trip, so our party had fresh pickings as will be seen below lots of fossils were found.  As the trip is now centred around these spoil heaps, this location is perfect for families to visit. Therefore we had quite a few families on our trip. 

The quarry was once used to supply building stone for the local town of Chipping Norton, which is located in the Cotswolds famous for its rich honey coloured stone buildings.

Cross Hands Quarry is a Site of Special Scientific Interest (SSSI) for its geological features. The rocks exposed in the quarry faces are mostly limestones, formed from the remains of shelly creatures living in the warm tropical seas which covered large areas of England in the Middle Jurassic Period, about 175 million years ago.

GEOLOGY

Cross Hands Quarry exposes rocks of Middle Jurassic age that were deposited in a shallow marine environment, not too dissimilar to that of the modern-day Bahamas. These rocks belong to the Inferior Oolite and comprise the Clypeus Grit, overlain by the Chipping Norton Limestone and the Hook Norton Limestone.

Towards the end of Upper Lias times sea levels fell somewhat, bringing a change of conditions which initiated the Middle Jurassic. Low sea levels persisted for 15 million years and in clear, warm, shallow waters the most important sediment was calcium carbonate. The accumulations of carbonate mud and carbonate sand have been transformed into a variety of limestones which are grouped into two series called the Inferior Oolite and the Great Oolite.

The word Oolite refers to a rock containing a proportion of polite. These are little spheres of calcium carbonate, typically half to one millimetre in diameter. The name comes from the Greek word on – meaning egg – because a densely oolitic limestone has the appearance of fish eggs.

The Inferior Oolite group of formations is so called not because of any inferior quality but because it’s rocks are older than, and therefore stratigraphically below, those of the Great Oolite. This limestone makes excellent building material as has been used in the Cotswolds to give the buildings there distinctive golden yellow colour.

SSI Noticeboard showing Geology and typical fossils that can be found at location.

During the Inferior Oolite and Great Oolite times this area was low-lying between shallow sea to the south-west and a swampy, coastal region to the north-east. In these shallow, variable environments the deposition of sediment varied greatly in amount and type from place to place and time to time. As a result the strata exhibit rapid lateral changes in thickness and character and some beds may be restricted to small areas.

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Geology Map of Whiltshire

In the early 1960’s remains of a partial right femur from a Cruxicheiros(meaning “cross hand”) is a genus of tetanuran theropod dinosaurwhich lived in the Middle Jurassic of England. The type species is C. newmanorum,described by Roger Benson and Jonathan Radley in 2010.  The 2010 paper recognized differences between the Cross Hands Quarry discovery and those attributed to Megalosaurus. These differences include lower and broader spines along the animal’s back, and differences in leg and hip bones. The authors renamed the Cross Hands Quarry specimens Cruxicheiros newmanorum; the generic name Cruxicheiros comes from a mixture of Latin and Greek, Latin crux meaning “cross” and Greek cheir meaning “hand,” in reference to the Cross Hands Quarry locality where the fossils were discovered. The specific name newmanorum honors the Newman family, who own the quarry. Cruxicheiroswas a large theropod, but the known material is very limited. The holotype, catalogued as WARMS G15770, is a partial right femur. Additional material from the site probably comes from the same individual as the holotype, based on examination of the matrix of sandy limestone and calcite which make up all the fossils. The additional material consists of “an anterior dorsal or posterior cervical vertebra; a dorsal neural arch; a partial dorsal vertebra; the anterior half of a middle-distal caudal vertebra; a partial right scapulocoracoid; a partial left ilium; the proximal end of a left pubis; [and] numerous rib and bone fragments”. The specimens are now stored at Warwickshire Museum Service (Source Wikipedia).

FINDS

Typical fossils found at this location are bivalves, brachiopods, gastropods, echinoids (such as Clypeus ploti).

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Nice big articulated bivalve – Pholadomya fidiculá
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Coral
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Lovely piece of Coral showing polyps
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Echinoid probably a Clypeus Ploti
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Echinoid – possibly a Nucleolites sp
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Gastropod- Bactroptyxis bacillus
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Gastropod – Purpuroidea morrisea

Many thanks to Mr Newman for allowing our party to visit his quarry.

UKAFH field trip to Ketton quarry, Rutland on 13th October 2018

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UKAFH were fortunate to gain access to this remarkable mile-wide working quarry on Saturday 13th October. A small group of us gathered on this unseasonably mild but breezy day for an excursion into the Middle Jurassic. We assembled in the site canteen for a briefing from UKAFH leader Sam Caethoven and the site management, taking time to enjoy the displays of some of the more exceptional finds to have been previously found at the quarry, before heading into the quarry itself.

Ketton Quarry is an enormous site which provides an extensive exposure of the middle Jurassic from rocks of Bathonian age (dating to around 165 million years ago) to Bajocian age (around 175 million years old). The mile-wide quarry has been worked for many decades and is now 115.6 hectares in size. With full access, this huge quarry provides opportunities to collect fossils from many different beds, however we were limited to an area of spoil where operations were not currently ongoing for safety and practical reasons. Despite this, fossils were still abundant.

The geology at Ketton is complex, with a range of Jurassic-aged rocks recorded. Mostly, three formations are visible in the quarries: the lowest is the oolitic Lincolnshire Limestone which was laid down in the middle Jurassic about 160 million years ago. This large, blocky, rock was formed from small grains of calcium carbonate which were deposited under a warm, shallow sub-tropical sea which was subject to reasonably strong currents. Above this is the Rutland Formation – bands of delta and shoreline muds and sands carried by rivers. Each band, with shelly remains at its base and tree roots at the top, was formed when sea-level rise topped the layer below. Many colours can be seen in fresh exposures of this formation. The exposures at the working quarry (Ketton Main Quarry) are the type formation for the Rutland Formation. Above the Rutland Formation is the Blisworth Limestone, laid down under quiet, shallow, warm conditions during a marine transgression. The Blisworth limestone is full of fossil corals and shells.

Ammonites can be found but bivalves, corals, brachiopods, gastropods, echinoids (such as Clypeus ploti), shark teeth and fish remains are more common. In the past, dinosaur footprints have been seen, along with fragments of their bones, but we were not that fortunate on this occasion.

Blocks of limestone are often full of bivalves, brachiopods, or corals but you need a good geological hammer and a chisel to extract them as they can be very solid, although some rocks will have weathered to the point that fossils can be easily picked out. There were also many loose fossils to collect.  Throughout our time on site we were able to find many bivalves and echinoids as well as a few brachiopods and gastropods.  Special mention goes to James who took the time to carefully search the fine matrial for quasi-microfossils and found numerous echinoid spines, fish teeth and an Acrodus sp. shark tooth.

At the end of our hunt we gathered in the canteen for refreshments and to enjoy seeing each thers’ finds.  It’s quite unusual on a UKAFH hunt for us all to finish together and have somewhere to gather for show-and-tell afterwards and it is always a highly enjoyable part of the day.  As well as seeing all the finds and learning more about the site, the quarry staff can also see what we have found, both to share in our enjoyment and to ensure that anything rare is reported and recorded.

UKAFH would like to thank Hanson Cement and the staff at Ketton quarry for allowing us to visit and taking care of us throughout the day, including briefing us, showing us the site and allowing us the use of their facilities.

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UKAFH field trip to Withington, Gloucestershire on Sunday 30th September 2018

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We were blessed with a warm, dry day for our first hunt at Withington in ploughed farm fields. The proximity of the topsoil to the Inferior Oolite below in this locality means that ploughing brings rock to the surface which contains a large variety of fossils. A field hunt really is an excellent way to find fossils with little effort other than to look patiently and “get your eye in”. The weather conditions were dry and overcast, making it an ideal day to fossil hunt as the rock was relatively clean and easy to spot so plenty of finds were made.

Once assembled at the farm, which we obtained special permission to visit, our guest leader and local expert for the day, Mark Baggott, gave us an introduction to the local geology and fossils. After enjoying Mark’s display and introduction to the site the group spread out to hunt across the two newly cleared fields and finds were quickly being made.  The lower field produced a good variety of abundant brachiopods, bivalves and regular echinoids and the upper field yielded complete and partial Clypeus ploti.  A number of members also found ammonites, which was unexpected as ammonite finds at this location have historically been quite uncommon.  Some beautiful gastropods were found and one lucky hunter even found a flint scraper!

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Mark Baggott’s fantastic display of Withington finds and geology and ID sheets

The Cotswold Escarpment rocks are almost exclusively marine and were deposited mainly in warm tropical seas. Plate tectonics has transported this part of the Earth’s crust northward over the last 150-200 million years to its current location. The Middle Jurassic rocks here are the characteristic ‘Cotswold Limestone’; soft, yellow, sandy limestone at the base of the Inferior Oolite (literally egg stone), a sedimentary rock formed from ooids, spherical grains composed of concentric layers. Towards the top of the Inferior Oolite the limestone becomes more fossiliferous and is referred to as ‘grits’ due to its coarser texture. Such an Inferior Oolite exposure is exposed at the farm and the fossils that this limestone contains date from between 167 to 175 million years ago at a time when this farm was at the bottom of a warm tropical sea. The rocks exposed near the farm comprise the Salperton and Aston Limestone and, from a fossil perspective, the most interesting layers are the Grits (Clypeus, Upper Trigonia Grit and Lower Trigonia Grit).

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Clypeus ploti found by Sam Caethoven

The commonest fossil found at this location is the sea urchin (echinoid) Clypeus ploti. These are more commonly known as Chedworth Buns (after the nearby village where they were often found) or Pound Stones, because their weight was usually a good approximation to 1lb. Clypeus lived in burrows on the seafloor, and burrowed their way through the sediment to get nutrients. They had fine hair-like spines and are an example of what is known as an “irregular” echinoid because they are shaped, not rounded.  Because these irregular echinoids lived in the sediment, they didn’t need the spiky and sometimes poisonous spines that the spiny sea urchins (known as regular echinoids) that we can see on the seafloor today have for protection. As well as the Clypeus Ploti we find other echinoid species which are “regular” and would have had sharp spines.  Unfortunately the spines rarely fossilize still attached, but they can frequently be found individually in the same sediment.

Trigonia bivalves gave their name to the second grit since they are very common at this horizon.  Trigonia are a family of saltwater clams, noticeable because the exterior of the shell is highly ornamented. Other fossils to be found comprise of brachiopods, bivalves and gastropods. Brachiopods are a marine animal that had hard valves (shells) on the upper and lower surfaces.  They are distinguished from bivalves which also have two valves/shells but in a left/right arrangement rather than upper and lower.

Brachiopods are bottom dwelling marine animals and, although rare today, in Jurassic times they dominated the sea floor and were frequently found in large colonies. One characteristic unique to brachiopods is the pedicle, which is a long, thin fleshy appendage which is used to burrow into the sea floor as an anchor while the brachiopod could feed clear of the silt.  Although the fleshy pedicle itself does not preserve in the fossils, the opening at the top of the animal from whence the pedicle connected (known as the foramen) is clearly visible. Brachiopods are filter feeders, gathering microscopic organisms and bits of organic matter from the water that flows by them using a specialized organ called a lophophore. This is a tube like structure with cilia (hair like projections). The cilia move food particles down the lophophore to the mouth.

Brachiopods are often known as lamp shells as the curved shell of the some classes look rather like Roman pottery lamps. There are two main groups of articulate brachiopods from the Jurassic, terebratulids and rhynchonellids. A common example of a telebratulid brachiopod found here is Stiphrothyris tumida; their main characteristics are their ovoid/circular shape, presence of a clear hinge line and a circular pedicle opening located in the beak. This brachiopod is a type example for lower Trigonia grit. The second of the main orders of articulate brachiopods is the rhynchonellids. The main characteristics are their strongly ribbed wedge shape, the absence of a clear hinge line, the line between the valves/shells is often zigzagged and a circular pedicle opening located in the beak. An example of such a brachiopod found here is Burmirhynchia sp.  The rhynchonellids were able to extrude their lophophore out of the shell in water, whereas the terebratulids maintained their lophophore within the shell.  The ability to extrude the lophophore led to more efficient food-gathering and is probably why rhynchonellids survived the mass extinction events better than the terebratulids.

Bivalves include such animals as clams, oysters, cockles, mussels, and scallops are also found at Withington. The majority are filter feeders and often they bury themselves in sediment where they can be safe from predators. Others lie on the sea floor or attach themselves to rocks or other hard surfaces, a few such as scallops are able to propel themselves through the water. The shell consists of two usually similar valves, and is joined at the hinge line by a flexible ligament with interlocking teeth on each valve. This arrangement allows the shell to be opened and closed for feeding without the two halves becoming disarticulated. Bivalves found here include Thracia (a member of the clam family) and Pleuromya (a member of the mussel family).

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Large ammonite found by Sarah Scott

If we compare brachiopods and bivalves, although they resemble bivalves, brachiopods are not even molluscs.  They are so unique that they have been placed in their own phylum, Brachiopoda. Brachiopods are shelled marine organisms that superficially resembled bivalves in that they are of similar size and have a hinged shell in two parts. However, brachiopods evolved from a very different ancestral line, and the resemblance to bivalves only arose because of a similar lifestyle. The differences between the two groups are due to their separate ancestral origins. Different initial structures have been adapted to solve the same problems, a case of convergent evolution. In modern times, brachiopods are not as common as bivalves. Brachiopod shells are often made of calcium phosphate as well as calcium carbonate, whereas bivalve shells are composed entirely of calcium carbonate.

Also to be found at Withington are gastropods. They are called univalves because they build a single coiled shell to protect their soft bodies. Ancient fossilized gastropods are related to living gastropods of today and are snails. Gastropods can be carnivorous or herbivorous. Their tongue is covered with thousands of tiny teeth to tear apart food.

UKAFH would like to sincerely thank the landowner for allowing us access to the fields.  Special thanks also to Mark Baggott for organising the visit and providing a fantastic display of local fossils and information for us all to refer to throughout the day.  Thank you also to Mark and to Alan Banyard for bringing along some very nice examples of undamaged and prepared Clypeus ploti and ammonites from nearby locations for members to take home.

UKAFH visit to King’s Dyke Nature Reserve, Sunday 19th August

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20180819_131316On 19th August UKAFH visited King’s Dyke Nature Reserve at Whittlesey near Peterborough.  This highly productive, family-friendly location is always a popular hunt and places quickly filled up so we had a full house of 35 with leaders Aidan Philpott and Sam Caethoven.

The geology of the location consists the Peterborough Member of the Oxford Clay Formation, representing the middle Jurassic period of circa 180 million years ago.  The clay is quarried for brick making but a spoil heap is provided in a designated area for fossil hunting and it was to this area we were destined today.

We were fortunate to enjoy warm but overcast weather, making hunting comfortable and dry. We kitted up we headed down to the dedicated fossil-hunting area where Aidan gave the group an introduction to the fossils that can be found.  The commonest finds are ammonites (especially Kosmoceras), belemnites (especially Hibolithes) and gryphaea, an oyster often called “Devil’s toenail” because of their curled, scaly appearance. However marine reptiles have also been commonly found in the quarry as well as teeth and bones from fish including the ray-finned Leedsichthys, probably the largest fish ever to have lived. An abundance of bivalves and brachiopods can also be found.

The location has an enormous quantity of fossils available and they are very easy to find, making it equally perfect for beginners who want to take home a treasure or two and for old hands who want to find something special, be it a bone, fish remains or a particularly large, complete or well-preserved specimen. The clay is easy to dig into and split so it is never a question of finding fossils; rather of narrowing down the large volume of finds into “keepers”. Soon we had good finds turning up, including calcite Kosmoceras ammonites, plenty of belemnite sections and an abundance of gryphaea.

Although on this occasion no-one was fortunate enough to find any reptile bone,  a Hybodus sp. shark tooth was found by Silas Shaul – the first I’ve personally encountered from this site. Well done Silas! Some sharp-eyed hunters like Billy Currie found small fish scales, bones and vertebrae and Tracey Herod found a beautifully preserved calcite-filled gastropod with its aragonite shell still in place.

As events drew to a close we received many kind remarks from attendees who commented on how they had enjoyed their day and were pleased with their finds.  We always love to hear your comments and see pictures of your finds, whether from one of our hunts or your own forays so please do share your news on our website and facebook pages!  Also please do sign up to our mailing list or keep an eye out on our website for forthcoming 2019 hunts which will be published soon.

Sam Caethoven

UKAFH visit to Betteshanger Country Park, Kent

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Betteshanger fossil spoil heap

On a scorching, sunny Sunday 5th August UKAFH members and guests headed to the south east corner of Kent to Betteshanger Country Park (near Deal) to hunt for Carboniferous plant fossils.

Betteshanger is a RIGS spoil heap at the old Betteshanger Colliery, which was the largest in Kent but was closed in 1989. Betteshanger Country Park was created by regeneration of the former Betteshanger colliery site and provides a large green parkland and recreation area ideal for walking, cycling and other outdoor activities.  However as part of Geoconservation Kent (http://www.geoconservationkent.org.uk/), there is agreement to retain a fossil hunting area within the country park. The fossil collecting spoil heap, which is northeast of the original site, is set aside for the study of the fossils to be found in the coal measures formerly mined there and this was our destination for the day.

Our group of 25 assembled outside the visitor centre, which offers toilets, showers, information on the park and a small cafe alongside a childrens’ play area.  From there it was quite a short walk to the fossil hunting area where Andy Temple of GeoConservation Kent awaited us as our special guest leader for the day. Andy regularly supports school and group trips and visits to Betteshanger and other Kent locations and is expert on the many, varied plant fossils to be found in the coal deposits.  Sam Caethoven welcomed the group and introduced Andy who gave an overview on the site and what can be found.

Betteshanger is Upper Carboniferous (Silesian) in age, from the mid-Westphalian Stage (Asturian Substage of 323.2–315.2 Mya) to the Stephanian Stage (Stephanian B Substage of 315.2–307 Mya). The rocks are from between 316–311 Mya and mostly consist of the Kent 5 coal seam, with some Kent 7. Kent 5 is assigned to the Upper Coal Measures (Warwickshire Group) and Kent 7 to the (South Wales) Middle Coal Measures. Fossils show that there were areas of forest and river levees, with overbank deposition taking place.

Fossils at Betteshanger are found either lying on top of the spoil heap or by digging into the spoil. Remains of Arthropleura, a large arthropod, have been found at the site. However, unlike other coal measures sites in Europe, no insects have been found at Betteshanger.

When we arrived at the fossil area we were delighted to be informed by Andy that a digger had just been in to turn over the coal spoil and dig out fresh areas, removing the old spoil that had already been examined many times previously.  As a result we were extremely fortunate to be able to find abundant, varied plant specimens!

Fossils were quickly being found, both in quantity and variety.  Kath Kemsley found a smashing Neuropteris seed fern and Aiden Philpott found an exquisitely preserved Alethopteris seed fern.  Jake Ashley found a very nice example of Lepidodendron (also known as a scale tree) which is an extinct lycopsid club moss.  Kaitlin Asher found a fantastic selection of plant fossils and Nicky Parslow uncovered a beautifully detailed example of asterophyllites horsetail.

The swampy Carboniferous landscape was dominated by three types of plant: ferns (true ferns and seed ferns), lycopods and sphenopsids.  Ferns were at their most abundant and diverse in the Carboniferous period but persist today. Giant lycopsids – clubmosses – such as Lepidodendron and Sigillaria grew to the height of trees and their fossilised bark is characterised by leaf scars. The fossils of the root systems of both these plants are called Stigmaria because they look so similar.  These are examples of form taxa, where a collection of organisms is given a taxonomic name but is known to be a grouping based on similar morphological characteristics, rather than more extensive biological similarity. Finally the sphenopsids consist horsetails which were gigantic in the Palaeozoic but persist today in much smaller and less diverse forms.  The leaves of horsetails, which form in whorls around the stem, are termed annularia but the root fossils are known as calamites.

Huge thanks to Andy Temple for bringing a fabulous display, expert advice, identification and preservation tips and plenty of very useful spare newspaper for wrapping finds!

 

Natural History Museum – behind the scenes January 29th 2018

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On 29th January UKAFH members were welcomed to London’s outstanding Natural History Museum (NHM).  The grand, terracotta-faced Victorian museum houses one of the world’s greatest natural history collections, with outstanding specimens on public display and a programme of world-class special exhibitions.  However, our visit was all about what is behind the scenes of this great museum.

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Our meeting point – “Sophie” the Stegosaurus – pretty cool!

Our fortunate group of fossil collectors assembled alongside “Sophie” – the most complete Stegosaurus fossil in the world – to meet our host for the day, Professor Adrian Lister, a specialist in mammals working in the Vertebrates and Anthropology section of the Earth Sciences Department.  Following a brief introduction we were led into the museum (“follow the jazz hands!”) and through the door from the public areas to the true heart of the museum.

It would be easy to make the mistake of believing the only purpose of the NHM is to educate the public with its displays, interactive facilities, information boards, exhibits and exhibitions.  However the NHM is in fact a vast repository of some 80 million specimens and functions as an incredibly important research facility.  There is a great deal more behind the scenes of NHM than meets the eye; certainly there is an extraordinary amount of space hidden away from the public areas – a veritable labyrinth of storage facilities, laboratories and research offices.  It would be impossible to see and absorb the true extent of this enormous hidden world in a day but our visit provided a brief glimpse into the real world of the NHM, it’s specimens and the people who study them.

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Prof. Adrian Lister welcomes our group

We began in a special reception area laid on for backstage visitors which showcases some of the museum’s prized specimens.  The small but exceptional display includes diverse examples of the world’s natural history, including fossils and minerals – a snapshot of time itself, if you will.  Adrian provided an outline of the day’s programme and introduced us to colleagues Zerina Johanson and Paul Taylor who would lead our party round specimens showcasing their personal research areas.

The NHM repository has its own stratigraphy of a sort: the dinosaurs and marine reptiles fossils are at the bottom, then working up the floors you travel through laboratories, birds, mammals, fish, bryozoa, molluscs, ammonites and so on.  Within those categories the arrangements can vary: mammals are arranged by geographical location; bryozoa by geological time; fishes by species.  Aside from the many researchers working within the museum there is an army of volunteers who help identify, label and digitise the multitude of specimens held.  The NHM is working on an extraordinary digital database which is publicly accessible and searchable and will provide an exceptional resource to professionals and amateurs alike, no matte their location.  The digitisation process also facilitates metadata, empowering the indexing and cross-referencing of specimens to make the whole far greater than the sum of its parts.

Introductions over, we divided into three groups to visit portions of the British mammal, bryozoa and fishes collections.  We had the great privilege of seeing some truly exceptional fossils and learning more about their recovery, preparation, conservation and use as specimens for scholars all over the world.

I came away from the mammal collection with a greater understanding of the abundance and relative diversity of “ice-age” mammals, learning about acquisition of collections from private collectors, whether by donation or purchase.  I also learned that mammoths possessed 6 sets of teeth during their lifetime, each successively larger as the beast grew, and that when the final set was worn down the animal was no longer able to feed adequately so the teeth determine not only the age of the animal but also its lifespan. Paul Taylor (who also regularly writes in our own Deposits Magazine) began by expressing great disappointment that Sir David Attenborough has never mentioned the sadly overlooked bryozoa; by the end of our fascinating tour of the collection we shared his mildly offended incredulity! Bryozoa are extraordinary colonial creatures which thrive in a multitude of ways, show multiple examples of convergent evolution through the fossil record and, despite being almost entirely obliterated by the P-T extinction event (the coloured dots on the specimen drawers told a tragic tale of this wipeout) managed a resurgence which means they still thrive today.  Microscopic photography revealed the mysteries of their feeding, breeding and defences. Finally, visiting the fishes with Zerina we saw examples of extraordinary conservation, with the most fragile of fossils being parted from or exposed within their rocky graves.  Such extraction can come at the price of fragility and loss of context (the matrix can be as important as the specimen in understanding the living environment, preservation and age of a fossil).  We saw exceptional casts and replicas of precious fossils and extraordinarily detailed 3D imaging of rare fossils, all enabling specimens to be handled, observed and studied across the world without the risk of loss or damage in transit of the original, precious fossil.

Following our visit to the collections we visited the Angela Marmont Centre (AMC) for UK Biodiversity.  Many of you may not be aware of this incredible free resource but we urge members to take the time to discover a little more by visiting in person or online! Located on the lower level of the Orange Zone of the museum by the Queen’s Gate entrance, the AMC provides a range of services and resources that benefits experts and amateurs alike.  Services are as diverse as pest identification, which assists in detecting and preventing crop pestilence and monitoring the spread of pests around the globe; and CITES certification which identifies and prevents the trafficking of rare and endangered animals and the products of such trade.  But more generally, they offer access to a large and diverse range of UK fossils which can be handled and studied and a vast array of UK biodiversity reference collection of such as insects, butterflies and bird eggs which can be examined.

The AMC has regular opening hours* for visitors to view the collections and also to make use of facilities such as the London Natural History Society’s library and also to bring in fossils and specimens for identification.  Aside from the in-person identification service they offer an excellent free online identification forum at www.nhm.ac.uk/natureplus/community/identification.  Further facilities include bookable resources such as microscopes, photo-stacking equipment, keys and field guides and workshop space suitable for meetings and training sessions.  There are also handouts and information leaflets, including specimen labels, which can be taken away.  This magnificent resource, which I have personally made use of on a number of occasions, is already benefiting a number of our members post-tour and we hope to welcome some of the AMC staff on future fossil hunts too!

Last but not least, of course we exited through the gift shops! NHM has a vast range of books and resources to purchase.  You can even buy our own book, “A Guide to Fossil Collecting in England and Wales” in the British Geological Survey (BGS) shop inside the museum.

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Look what UKAFH leader Aidan found in the BGS shop!

The passion and knowledge of our tour hosts was self-evident and we are most grateful to Adrian, Zerina and Paul and to Christina, Ben and Florin at AMC for their time.  We also noted that our hosts had taken the time to understand our group and activities and had specifically shown us examples of specimens that we may have found ourselves, or been able to look for, on past and forthcoming UKAFH hunts.  This thoughtful attention to detail did not go unnoticed! Thank you for giving up your time for us to create such a special day.

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Left to right: UKAFH Leaders Nicky Parslow, Salma Khaliq, Eliott Mills, Aidan Philpott and Sam Caethoven celebrate a great day! Jazz hands!!

*The AMC’s opening hours are 10-12 and 2-4pm Monday to Friday, and the first Saturday of the month.

Field trip to Lyme Regis February 3rd 2018

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It was grey, cold and with weather forecasts that Captain Scott would have shuddered at the thought of! Undeterred, our group met in the Charmouth Road car park and descended to the beach, via the new sea wall next to Church Cliffs, with unsurpassed views of Lyme Bay and to Seatown and Golden Cap in the east. After a welcome to the delights of the Jurassic Coast location and an introductory talk, which took in the geology, Mary Anning, coprolites, public toilets, cliff falls, David Attenborough’s ‘Sea Dragon’, an introductions to UKAFH staff and our ‘guest helper’, Brandon Lennon, we all headed east.

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The geology here at Lyme Regis is quite complex. The cliffs and foreshore between Lyme Regis and Charmouth represent three stages within the Early Jurassic (or Lias) period termed the Hettangian, Sinemurian and Pliensbachian, dating from approximately 199-189 million years ago.

Essentially the rocks at Church Cliffs are Jurassic-aged from the Sinemurian stage. The Hettangian stage rocks of the older Blue Lias slowly dips away eastwards beneath sea level and the Shales-with-Beef layer, capped by the Black Ven Marls (part of the Black Ven Mudstone Member) and in turn, part of thr Charmouth Mudstone Formation descend to the beach under Black Ven. The younger Pliensbachian rocks are best studied at Charmouth. During this time a shallow epicontinental sea (less than 100m deep), was present across much of Europe, including most of England, Wales and Ireland, and laid down alternating layers of clay and limestone. At that time, Lyme Regis (as it’s now known), lay closer to the equator, roughly at the latitude North Africa is today.

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Armed with all the background, our intrepid explorers heading off. The best place to look for fossils is among the pebbles and rock pools on the foreshore, loose fossils including ammonites, belemnites and reptile bones can all be found with a little patience. Fossils can also be found protruding through the surface of the slumping clays along the top of the beach. At high tide the waves wash away the soft clay, leaving the more resistant fossils exposed and able to be collected by hand.

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Our hunt took place on an exceptionally low tide and Lyme’s famous ledges soon began to appear. This is usually a great place to look, as fossils are washed out of Black Ven’s clays and are deposited in the rocks and boulders and in fissures on the ledges. But finds were remarkably thin on the ground and despite some of our party finding a few very small ammonites, along with fragments from larger specimens, not much else turned up. Andrew Baylis found an ichthyosaur vertebra, which is a common find at Lyme Regis. However, the rain, sleet and snow forecast did not materialise! How wrong can the forecasters get it?

As the tide extended further out into the bay, boulders with large ammonite impressions appeared, not dissimilar to those found on the ‘Ammonite Pavement’ on Monmouth Beach.

Finding fossils is never guaranteed and participants of this hunt were not disappointed with the few specimens that were found. The coastal scenery was dramatic and the forecast inclement weather held off! Many thanks o all who attended, many of whom went on to the Charmouth Heritage Centre, to see the newly displayed ichthyosaur skeleton, discovered recently at Lyme Regis and made famous by David Attenborough’s ‘Sea Dragon’ BBC documentary.

 

The Art of Extinct Animals: Pop-Up Palaeoart Exhibition

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On Wednesday 13th December King’s College London, in association with the Popularizing Palaeontology Workshop II, hosted a pop-up palaeoart exhibition “The Art of Extinct Animals” featuring some of the UK’s leading palaeontological artists who showcased their artwork and talked about how they go about reconstructing extinct animals and lost environments.

The one-off event engaged with questions like: How can artists reconstruct and recreate the life of the past? What challenges, techniques and difficulties are there in this process?  How does the history of palaeontological artwork affect current conventions in the field?  And what does palaeontological artwork tell us about the relations between science and art? The palaeoartists featured were Bob Nicholls, Mark Witton, Beth Windle and John Conway.

The first talk, delivered by Bob Nicholls, was ‘No, we don’t make it up! Palaeo-reconstruction explained from the inside-out.’

Bob used his reconstruction of Psittacosaurus as a case study to describe his process of building a physical representation of a dinosaur from its fossil, beginning with taking many detailed photographs and measurements of the fossil, including 3D prints to help reconstruct the skeleton and whatever traces remain of details of skin and soft tissue. He then considers the soft parts such as musculature and skin, drawing on evidence on the fossil for them, and considers the creature’s respiratory, digestive, circulatory, nervous and other systems and how these might have been laid out in the creature’s body.  We can draw on living creatures to help imagine this.  Bob stressed that it is important to overcome preconceptions of what the animal may have looked like; in other words, let the science speak.)

Bob creates palaeoart both traditionally (paint and brushes), using software and also as sculpture.  Psittacosaurus is a sculpture so the next steps were to create an armature and clay model which was then coated in silicone to preserve detail then in fibreglass to keep it stiff. The sculpture was then cast, after which it needs to be repaired and tidied up before the final stage of painting takes place.

When deciding which colours to use it can be difficult or impossible to know but scientific developments are progressing constantly and new techniques enable us to learn more from fossils than ever before.  Melanin preserved in fossils indicate likely colours.  A good deal can also be surmised by considering the environment inhabited by the creature, evidenced by the other fossils found alongside, trace fossils like coprolites and the geographical location of the creature at the time of death and likely climate. For example, countercolouration is determined by environment – the amount of light, affected by latitude and habitat, determines the degree, acuteness and position on the body of countercolouration. By placing the model in a similar environment to that it is thought to have inhabited you can assess and inform decisions on how to place countercolouration. Other considerations include carotenoids, porphyries, pterines and purines in fossils, which also inform colour, and patterns in nature.

Next to speak was Mark Witton, whose topic was ‘The science of extinct animal life appearance: why “what did it look like?” is not just a question for palaeoartists (or children).’

Mark observed that it is natural to look at a fossil and wonder “what did it look like?” – palaeoart is about answering that, not by making it up but through scientific research. Palaeoart is more than basic anatomy – lots of new science is constantly revealing more information. So is palaeoart only to inform the lay person/children (non-specialists)? Is it too unknowable/speculative/scientifically meaningless? Is it not relevant to other fields of science? Can palaeoart serve science? Yes. Mark took us through examples of how fossils lead to the artist considering what the remains tell us about the animal and therefore how to depict it.  Considering Arsinoitherium (an extinct horned mammal from the Eocene), the horn bone is not dense so what covered it to make it strong? Nature tells us this was likely a keratin sheath.  Keratin rarely fossilizes so we cannot see it in the fossil so this makes us ask “what did it look like?” and question how the horns were used. Different horn types exist in modern nature which can be compared to fossils for similarities and the type of headgear extrapolated.

Considering Triceratops, it is hard to predict shape of the horn from the bone fossil because it isn’t the complete story so you need to think beyond that and consider how horn grows. For triceratops the horn shape reconstruction tells us the shape changes with age as a result of how horn grows, adding layers within the horn and pushing the earlier layers out and up. Taking another example, Tanystropheus, the fossil might be interpreted as a marine reptile with a long neck or a shore-based angler.  Studying the skeleton more closely, tong cervical ribs and a large scapular area for muscular attachment gives power to lift and support the neck. Since this musculature and skeleton would not be necessary in water because water alone would provide sufficient support to the neck we can predict that the creature was a land based fisher.

So, the inquiring mind of the palaeoartist informs the artist how to build the creature up from bone to flesh, which habitat to place it in and how it interacts with other creatures in battle, mating and feeding.  At the same time this rigorous inquiry and the resultant art feeds back into science, providing new hypotheses and giving context to scientists to then inquire further too.

Finally, Mark drew audience attention to a forthcoming publication, “The palaeoartists handbook”. Which is out in 2018 and published by Crowood Press.

The next speaker was emerging palaeoartist Beth Windle, whose topic was ‘Illustrating Mammals from Specimens, Life & Location.’

Beth’s primary artistic focus is the Hyena, a creature known and rercognised by most people in its modern form but which would have looked dramatically different during the Pleistocene due to a far cooler climate.  Although genetically the same species as modern Hyenas, those of the Pleistocene would have borne thick, fluffy coats and predated on different animals to today.  Beth strives to understand intimately how this creature and its environment would have looked and portray this in her art.

Beth spoke with passion about how good palaeoart must be informed by drawing from real life observation rather than relying on past art or Google.  As an example, when it snowed recently Beth went out and sketched to capture the English Pleistocene-like environment.  She recommended artists visit museums and collections and handle and draw real specimens and visit zoos and wildlife parks and observe and draw from life and real animal movement. Whilst we might not know exactly what a creature looked like, if we can understand its build and it’s habitat, and we really know how to draw animals and landscapes which contain movement and life, we can create good palaeoart.

Finally the audience heard John Conway expound on ‘Paleoart is the Best Art.’

John is an artist who sometimes draws dinosaurs and sometimes doesn’t.  John elected to argue that palaeoart has the potential to be a mainstream art movement. John provided a complete – and very entertaining – art history lesson taking us from the beginnings of fine art right up to the modern day, arguing that art has already done everything from realism to abstraction so what is left to be done? Can palaeoart be fine art? Is palaeoart impeded by being representational?  Palaeontology provides a new subject for art. Yes, it is technical, but that’s not novel. Art has been technical, fantastical, realistic and everything palaeoart is.  So why hasn’t palaeoart become mainstream? Is it because it’s never been pitched as art for its own sake? Palaeoart can inform and entertain. So what is stopping it from transitioning from the stuff of science at one extreme and of childrens’ playgrounds at the other?  John didn’t answer the question but left it as food for thought.  One thing was certain; the audience at tonight’s event would certainly be glad to see more palaeoart!

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John Conway talks to the subject of palaeoart as a mainstream art form

Following the presentations the audience was able to return to the art displays to appreciate with fresh eyes the palaeoart on display by the four artists, including items available for purchase. All the artists were open to questions about their art and about palaeontology and some very interesting discussions ensued, from the likely function of the hind paddles of a plesiosaur to which creature of highly limited fossil evidence would the artists most like to be able to understand and portray.

Thank you to the event hosts and organisers, King’s College London and Popularizing Palaeontology Workshop II, and the artists for putting on such an interesting and informative event.

UKAFH weekender at Folkestone and Samphire Hoe, Kent 14th and 15th October 2017

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The Folkestone foreshore

On Saturday 14th October UKAFH took a group out to the Warren, Folkestone for day one of the Kent weekender.  We were blessed with unseasonably warm weather as our group of 30 descended the (pleasantly dry) mud footpath down to the beach to begin our hunt through the Cretaceous period! Once on the beach, UKAFH leader Chris Tait briefed the group on the geology of the location and what we might expect to find.

The rocks at Folkestone represent the Albian stage of the lower Cretaceous, 110-105 mya.  Lower Greensand is found at the base of the cliff with Lower and Upper Gault clay resting conformably atop, however the clay slumps over the Lower Greensand and is eroded at sea level to release large volumes of fossils onto the beach in this highly productive locality for fossil hunting.  During the time these sediments were laid down the UK was at a more southerly latitude in the area of the modern day Mediterranean and a warm sea teeming with life covered the UK.  During this time sea levels were transgressing, with the Lower Greensand being deposited as and continued to erode, to be replaced with fine clay sediments once nearby land was completely submerged.

The Lower Greensand is less fossiliferous as the near-shore environment it represents was less suitable as a habitat but still contains excellent fossils such as ammonites; the Gault Clay, however, is packed with diverse fossils, some with exceptional preservation. Ammonites, belemnites and molluscs are common; nautilus, crabs, crinoids, fish remains, shark teeth and scaphopods can be found, along with rare finds of reptilia. Examples of all of these were found by members of our hunt group!

Phosphatised preservation is typical but quality is variable, with examples often fragmented or in nodules.  However many examples are preserved in superb detail in pyrite and those which are newly emerged from the clay can retain some or all of their nacrous shell.  Bivalves and molluscs which are newly exposed are often extremely fragile and are rarely collectable unless carefully removed along with the surrounding clay, but ammonites are more durable and make marvellous specimens to add to a collection.

Soon after we reached the beach heading towards Copt Point the finds were already plentiful.  Partial regular and heteromorph (partially uncoiled) ammonites and bivalves were quite common and finds increased as people “got their eye in”. Some of the group progressed quite quickly along the beach to inspect the slips of clay for freshly washed out fossils and check out the shingle between the large rocks and boulders on the foreshore. Others remained nearer the start of the beach, working methodically through the shingle by hand, with a trowel, or dry sieving, in search of smaller finds like shark teeth.

Several members of the group found shark teeth, with Isabelle finding the largest example.  At the other end of the scale, Sam found a small but scarce Acrodus shark tooth while sieving using a 3mm mesh. Sieving is a good technique to remove sand and search for small fossils which wash out higher up the beach because they are lighter. Sieving and shingle-searching up the beach yielded crabs, solitary corals, urchin spines, shark teeth and vertebrae as well as fish teeth, a turtle bone and the day’s star find, a swordfish tooth!

By the end of the day we had a really great selection of finds amongst the group!

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Leader Selfie

The following day we were greeted with yet another gloriously sunny autumn day, enhanced by the towering white cliffs of Dover above our meeting point as Samphire Hoe Country Park.  We had another full house of attendees and headed west along the beach to hunt for fossils amongst the chalk boulders on the foreshore.  Aidan Philpott, UKAFH Leader, explained the geology and identified local fossils to look for to the group. The lower chalk (also known as the grey chalk) at Samphire Hoe is from the Cenomanian stage of the Upper Cretaceous so yields fossils aged 100.5 – 93.9 Mya.

Common finds are brachiopods, bivalves and echinoids. Sponges, shark teeth, worm tubes, gastropods and fish can also be found and, rarely, ammonites. As well as beautifully preserved fossils within the chalk, some echinoids and shells and many sponges form flint casts which can be washed out of the chalk and found in the shingle.  Attractive pyrite crystals can also be found in the chalk.

Our first find of the lay was an eroded echinoid inside a flint block.  UKAFH leader Chris Tait then found a large section of clam.  These giant molluscs are mostly found broken into small pieces so this was a really nice find.  As the day progressed a good variety of finds were made including echinoids, shark teeth and brachipods.

Samphire Hoe isn’t the easiest location for fossil hunting as you need to scrutinise the loose chalk boulders on the foreshore carefully for signs of fossils and then extract them very carefully with a chisel to ensure they are not damaged.  You can also hammer the boulders to break the chalk up in search of fossils so work, tools and care are needed to have a good chance of finding fossils here.  Once extracted, however, preservation is usually excellent, with fine details clearly visible.

Cleaning chalk fossils is easy, requiring little more than dry brushing the remaining chalk matrix with a soft brush (a children’s toothbrush is ideal) to remove any chalk remaining on the fossil surface.  As chalk is very soft, you can easily remove larger amounts of remaining chalk with a blunt knife or craft knife until you approach the surface of the fossil and switch to brushing.

Finds were pleasing but not abundant, however everyone enjoyed the hunt and the sunshine day.

Chris, Aidan and Sam, your UKAFH leaders, would like to thank all of our members and attendees for joining us on our weekend fossil extravaganza and we look forward to seeing you all soon!

Click here for our UKAFH news and to see out upcoming events (we update the list regularly so check back often!)

FOSSIL HUNTING EVENTS

 

 

UKAFH visit Seatown, 10th September 2017

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On September the 10th, (which was a very blustery day) UKAFH set off on a hunt towards Golden Cap from Seatown.

In the right scouring conditions when the ledges are uncovered from the shingle, Seatown beach can be incredibly productive with the Belemnite Marls exposed – bringing out countless iron pyrite ammonites, crinoid stems and belemnites. Unfortunately, despite the gale that was blowing, the ledges remained covered.

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Seatown beach on the 10th of September
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Seatown beach when the ledges are exposed.

We worked along the landslips on route to Golden Cap. The slips can produce green nodules (named because of the green calcite that makes up the preservation of the ammonites within). which contain many different ammonites, occasionally bivalves and very occasionally marine reptile remains. Within these nodule beds it is also possible to find parts of ammonites which have not been preserved within a nodule have been partially preserved. Many partially crushed Androgynoceras ammonites were found by members of the group, along with plenty of belemnites.

Once the group reached Golden Cap, we explored a little around the exposed Belemnite Marls and the landslips on the Seatown side (any further round, the wind became far too strong!). More belemnites and Androgynoceras ammonites were found. Despite the weather some great fossils were found!

Thanks to all who came along to Seatown and we hope you enjoyed the experience of