fossils
UKAFH field trip to Folkestone Sunday 6th October 2019
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.
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 Withington, near Cheltenham, Saturday 5th October 2019
UKAFH hosted its largest field trip ever on Saturday 5th October when we welcomed 50 members, many of them new joiners, to privately owned ploughed farm fields near Withington which we had obtained permission from the landlord to visit. 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 (with landlord permission) really is an excellent way to find fossils with little effort other than to look patiently and “get your eye in”. It is comparatively easy to find rocks on the surface of the topsoil and inspect them for fossils, many of which are already loose from the rock. No tools or equipment are required other than a container for your finds and, at this location, a bucket was ideal as fossils were plentiful and they are easy to carry and drop the robust fossils into as you go along.
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.
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), named from the index fossils found in those rocks.
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.
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.
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).
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 and to Andy Crawte and Alan Banyard who gave their time to assist our attendees in identifying their finds.
All in all we had a great day out and it was wonderful to welcome so many enthusiastic new members and see so many families enjoying what was for many of them their first fossil hunt. Everyone went away with finds and I saw many happy smiles! This is exactly what UKAFH is all about and I really hope we see many of you on future fossil hunts. Our 2020 hunt calendar has now been published so please take a look and I hope to see you all soon!
UKAFH field trip to Doniford Bay, Somerset on 15th September 2019
On 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!
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.
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.
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.
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
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 visit to Seaham, Sunday 11th November 2018
On Sunday 11th November, UKAFH met on the coastline of Co. Durham, just outside Seaham, a small town about 6 miles south of Sunderland.
Unusually for a coastal hunt, we were focused on the spoil heap of the former Dawdon colliery that operated close by. Dawdon colliery began extracting coal in 1907, mining the Carboniferous coal seems far below the Permian bedrock the cliffs at this location are composed of. The spoil from the colliery consists of inferior coal, shales and mudstone which were dumped over the cliff edge, creating, in places, a second cliff of carboniferous material in front the Permian cliffs. Although once the most productive colliery in County Durham, employing over 3800 people, Dawdon colliery ceased extracting coal in 1991. Since then, most of the carboniferous sediment had been eroded away by the sea, but there is still ample opportunity to find spectacular fossils here.
The spoil consists of Carboniferous material about 320 million years old. At the time the sediment was created, County Durham was a vast and boggy forest. The upper canopy was densely foliated with the likes of Calamites trees – related to modern day horsetails, and Lepidodendron trees – related to modern day club mosses, although their modern-day ancestors are diminutive, these trees would have towered over 100ft above the forest floor. The forest floor, where abundant pteridosperms (seed ferns) such as Neuropteris thrived was hydrated and boggy, an ideal environment to preserve the foliage and timber which over millions of years built up to create the coal seems which were so highly prized here during industrial times. Also present in this forest of giant tree like plants were the giant insects the Carboniferous is also famous for – huge dragon flies would have traversed the dense canopy while monstrous millipedes up to 6ft in length would have scurried below. Although insect fossils are extremely rare, it is still something to keep an eye out for.
In complete contrast, the cliffs behind the carboniferous spoil is Permian in age, about 290 million years old and is formed of limestone from a shallow marine environment. Although Seaham is one of the best locations to find carboniferous plant fossils in the UK, the limestone originating from the cliffs should not be overlooked as these can contain bivalves, crinoids, corals and rare but possible fish remains.
After some examples of possible finds provided by Mike Greaves, we took a steep path from the national trust carpark at Nose Point down to the beach. We didn’t know it until we were on the beach that the path we followed and the apparent shelf we were now standing on was in fact the spoil from the former colliery. Here, Katherine Combe MSc provided a talk about the geology and where we were likely to find fossils. It wasn’t long before fossils were found, although the first fossils were that of crinoids originating from the Permian limestone of the cliffs. As we stepped off the spoil onto the beach the first plant fossils were found. Alice Brooks found a great Stigmaria fossil (part the of rhizomatous root of a Calamites tree) and Terry Newsome found some incredible fronds by carefully splitting shale.
Later we headed towards the foreshore where large sections of Lepidodendron trunks could be seen. Here, denser mudstones could be split with a hammer to reveal an abundance of well-preserved pteridosperm such as Neuropteris within. Jake and Matt Ellison found some delicately preserved Calamites leaves, Ben Simpson found some great Sigillaria and Ethan Wale found some beautifully preserved fronds. Mike Greaves found a stunning example of Calamites amongst the shingle.
We were grateful for the calm weather, apart from a few spots of drizzle, the temperature was mild, the wind was light, and we saw a glimpse of sunshine at times.
Being remembrance Sunday, we gathered and observed a two-minute silence at 11am. As an important supplier of coal to Britain during the Second World War, Dawdon Collier was bombed by the Luftwaffe in August 1940 which killed 12 and left 119 people homeless. This then, was a poignant place and time to remember those who have given their lives, not only in battle but also supporting the war effort back home, such as here, producing the supplies needed to win the war.
Thank you to everyone who joined us. A great group of people and some fantastic finds!
UKAFH field trip to Cross hands quarry, Warwickshire on 21st October 2018
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.
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.
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).
Many thanks to Mr Newman for allowing our party to visit his quarry.
UKAFH field trip to Ketton quarry, Rutland on 13th October 2018
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.
UKAFH field trip to Withington, Gloucestershire on Sunday 30th September 2018
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!
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).
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).
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
On 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
field trip to Ramsholt – 10th June 2018
On Sunday June 10th UKAFH visited Ramsholt, located on the river Deben in Suffolk. We met near the Ramsholt Arms, a popular pub with tourists and boaters, then walked about 2 miles north through woodland and along the river bank before reaching a shingle beach where fossils are abundant.
UKAFH leader Sam Caethoven explained the geology and pre-history of the site and provided an example of likely finds.
There are three distinct deposits exposed at Ramsholt. The base of the small exposed cliffs and the foreshore consist of London Clay, a roughly 50 million year old marine deposit commonly exposed on the south east coast from which many bivalves, gastropods, crabs, lobsters, shark and ray teeth, fish, reptile and mammal remains can be found. Above the London Clay sits the Coralline Crag formation, a much younger (~ 5 million year old) sandy sediment containing numerous bivalve and gastropod remains. As the name suggests, the formation does contain corals however more common here are bryozoans, which can often be found with corals seeded within their chambers. The 5 million year old Coralline Crag comes to lay directly on top of the 50 million year old London clay as the underlying sediment was eroded before the Crag formed, this has resulted in a diversity of derived fossils in what is called the Basement Bed, directly above the Coralline Crag and forming the base of the roughly 2.5 million year old Red Crag above it. Derived fossils are those which, having become fossilised in one deposit have since been eroded out, often transported by rivers or tides, and become part of a much younger sediment. This means that, within the basement bed, fossils from the Eocene and Miocene can be found and even Cretaceous belemnites and crinoids have been found within the basement bed. The effects of “refossilisation” of shark teeth here are striking; the teeth are often polished and the colours derived from exposure to different elements are diverse and vivid. Marine mammal bone fragments, often attributed to whales, are also common from this bed and have become silicaceous in their preservation. The iron rich Red Crag above is also noted for well preserved and often complete bivalves and gastropods.
Finding fossils here is relatively easy as they can be found in abundance among the shingle of the foreshore – the site is SSSI protected and so digging in the cliffs or the exposed clay on the foreshore is prohibited. With fine, dry and warm weather it was not long before the group began making discoveries. Gastropods and bivalves from the Red Crag and Bryozoans from the Coralline Crag were the first fossils we noticed as we progressed north along the foreshore.
But it was not long before shark and ray teeth were being found, some fantastically preserved and some with vivid red, orange and even blue colours. Daniel Austin found a particularly rare and large Isurus tooth while Eliott Mills found an uncommon large Otodus tooth.
Other notable finds included some large pieces of marine mammal bone and a delightful although heavily worn crab carapace found by Aidan Philpott.
The day was fruitful with many excellent finds including some of the rarer shark teeth from this location. Big thanks to everyone who attended and made the day so enjoyable and special thanks to Sam Caethoven, Eliott Mills and Salma Khaliq for doing a sterling job leading the hunt. Hope to see you all again soon.
Please remember when visiting Ramsholt that the site is SSSI protected and so digging in the cliffs or the exposed clay on the foreshore is prohibited.
Wrens Nest, May 2018
We had the pleasure of returning to a very pleasant and dry Wrens’ Nest in Dudley on the 12th May 2018 to hunt for the elusive “Dudley bug”.
Wren’s Nest is composed of limestone from the Silurian Wenlock Group and is famous for the Phacopid trilobite Calymene blumenbachii, which featured on the Dudley County Borough Council Coat of Arms until 1974.
A former Victorian Quarry, which ceased operation in the 1920s, Wren’s Nest is now a National Nature Reserve and a Site of Special Scientific Interest due to the fossils that can be found here. And what a site it is!
It is a fantastic site for fossil hunting as so many fossils can be found loose on the ground. Over 700 different species of fossils can be found here, over 80 of which can be found nowhere else on earth.
Wren’s Nest contains the most diverse and abundant fossil fauna found in the British Isles and the fossils are among the most perfectly preserved Silurian fossils in the world.
Many attendees were young, first time fossil hunters and looked fabulous in their new hi-vis! We had lots of families and newcomers, which was great.
We started the day with a potted history of the site and a “show and tell” of the types of fossil that could be found at the site. The first few hours of hunting were spent at the reef mounds, before moving onto the fossil trench, from where we had a lovely view of the ripple beds.
The group found some marvellous partial trilobites (heads and tails – shown above and below), gastropods, brachiopods, bryozoans, corals and sponges – a fabulous slice of a Silurian reef ecosystem.
To all that attended, we hope that you enjoyed your day, and to the first-time hunters, we hope that we have inspired you to begin a wonderful new hobby!
UKAFH Weekender – Isle of Wight 2018
On 14 and 15 April 2018, UKAFH conducted its first weekend event of the year. UKAFH members from across the UK left the mainland behind and sailed across the Solent to the sunny and highly fossiliferous shores of the Isle of Wight.
On Saturday, 14 April, we descended onto Thorness Bay, which is on the north coast of the island. Access to the bay is through Parkdean Thorness Bay Holiday Park, where many of the group were staying in caravans or, the bravest amongst us in tents. The park has excellent facilities, such as toilets, and a bar and restaurant, as well as ample parking and a small supermarket, which made it a very comfortable start to the day.
The weather was glorious and sunny – the first really warm and sunny day of the year, which filled us with hope and anticipation. In fact, we couldn’t have hoped for better or more relaxing weather.
We began in the car park, where Chris Tait and Nicky Parslow displayed some of the fossils that we were likely to find from the Oligocene epoch, such as carapaces from Emys and Trionyx turtles, and scuta from Diplocynodon alligators. We also saw shiny fish bones and vertebrae, and the very rare mammal teeth of Elomeryx – a stout hippopotamus/pig like creature. In addition, we saw echinoids preserved in flint, which can be found derived from the much older Cretaceous sediments.
We walked as a group down the gentle slope from the carpark to the beginning of the bay, where Chris pointed out the Bembridge Insect Beds to the east and where, unfortunately, fossils are few and hard to find. So, we set off to the west, where we could see a gently sloping shingle beach, with some exposures of green/blue clay from the highly fossiliferous Hamstead Beds. Chris explained to us that the best collecting technique is to look carefully and move slowly, and that moving the gravel with a trowel would likely result in uncovering fossils. Chris also painted a picture of what Thorness Bay might have looked like during the Oligocene epoch, about 30 million years ago – a lagoonal area within an estuary, where alligators, turtles and fish would have swum and hunted. Elomeryx porcinus would have been seen grazing on the edge of the lagoon and also swimming out to eat the plants growing in the lagoon. It would have been much warmer during the Oligocene, averaging 20 to 25oC, as the location lay much further south, closer to the equator.
As we headed west, we found that the first part of the bay was less productive than further along, but most people found gastropods, bivalves and fragments of turtle and fish during the early part of the hunt. As we moved along the bay, the first major find was found by UKAFH leader, Elliot Mills, who found a rare E. porcinus tooth and a fish vertebra on the surface of the shingle, within a few centimetres of each other. The group continued to round the first two corners, where more and more fossils were found. Silas Shaul found a beautiful echinoid preserved in flint, high up on the tide line. As pointed out above, this would not have come from the Oligocene epoch, but from the much earlier Cretaceous period. Isabella Rice found part of a Diplocynodon alligator scute and Nicky Parslow found part of an alligator jaw.
As the afternoon drew late, we ambled back to the holiday park and got cleaned up before the evening’s entertainment. At 7pm, we met up in the bar area of Parkdean and, at 7.30pm, Aidan Philpott presented a quiz to four teams. This was quite challenging, but fun at the same time, and there were several prizes, which were distributed for achievements, such as the Best Team Name – “The Not Crocodiles” and the Best Wrong Answer – “Strawberry Daiquiri” in answer to the question “What Beverage is Sir Hans Sloane often credited with having introduced to the UK?” (The answer is actually hot chocolate.) The Yan family won the quiz with a fantastic score of 15 and claimed the golden hammer.
After the success and glorious weather of Saturday’s hunt at Thorness Bay, we met on a drizzly Sunday afternoon at Brook Bay on the west coast of the island.
The cliffs and foreshore at Brook Bay represent part of the Wessex Formation, which is a mixture of mudstone, sandstone and clay. This was deposited during the Barremian age of the Cretaceous period, about 127 million years ago, in what was a large river basin that drained the surrounding hills. At the time, the climate here was warm and intensely seasonal. This intense seasonality is key to understanding the type and abundance of fossils found here. The landscape would have had rivers and tributaries running throughout it, with ponds, lakes and boggy areas – notable in the fossil record by the abundance of fresh water bivalves and fish remains. The water source and warm climate meant the area was, for much of the time, densely vegetated – the abundance of plant fossils here is immediately noticeable in the form of black, shiny lignite that litters the beach.
The dense vegetation would have attracted herbivorous dinosaurs, such as huge iguanodonts, sauropods and the heavily armoured Polacanthus, and the presence of herbivores would have attracted carnivores, such as the enigmatic allosaurid, Neovenator salerii (the bones of which can be seen at the Dinosaur Isle museum at Sandown). These dinosaurs left their footprints in the mud surrounding the rivers, ponds and lakes. The dry season then came, rivers ran dry, ponds vanished and lakes became anoxic, with the footprints left in once soft muddy sediment becoming solidified among a parched landscape. Charcoal derived from brush fires found in the Wessex Formation, indicate just how intense the dry seasons would have been. The wet season then followed, which is key to understanding the abundance of fossils here. Intense storms would have caused massive flooding, rapidly depositing sediment in the area, burying plant remains, bivalves and bones, as well as filling the dinosaur footprints with coarse sediment, forming casts of the footprints. Brook bay is famous for its dinosaur foot casts, which, after scouring conditions, can number in the hundreds along the beach.
After a talk about the geology and examples of likely finds by Aidan Philpott, we headed north towards Hanover Point, looking amongst the shingle for ‘rolled’ dinosaur bone. Dinosaur bone is commonly found along this stretch of beach. However, it can be hard to spot amongst the abundance of similarly coloured lignite, but we were an eagle-eyed group and bone was soon being discovered. Dinosaur bone here is often described, as ‘rolled’, as it is most commonly found worn, weathered and rarely articulated – not only from being exposed to beach conditions, but also from the intense storms and flooding it experienced before becoming fossilised. This often makes it hard to identify what bone it is or what animal it came from. However, Silas Shaul made a cracking find of a clearly defined dinosaur toe bone. As well as dinosaur bone, other notable finds included a Sheenstia fish scale found by Emma Philpott and the impression of a pine or cycadean cone found by Elliot Mills.
As the tide fell, the group explored the exposed soft ledges for fossils lodged in the rock pools. Nicky Parslow found some beautiful small in situ footprints on these ledges, which we were able to admire and photograph before they are lost to tidal action.
Later in the afternoon, the drizzle stopped and the sun began shining. As the tide had now retreated, it was a perfect opportunity to show the group a dinosaur trackway exposed far out on the shelf, as well as the impressive Pine Raft. The Pine Raft helps to illustrate just how intense the flooding that occurred here was. Preserved amongst the clay and mudstone are the remains of huge tree trunks, which would have been transported by a flooding event and lodged within the river system, where plant debris continued to build up. It is fascinating to see these huge trees in situ, which really helps us to visualise the area 127 million years ago. The dinosaur trackway also helps to visualise the animals that would have lived here. Exposed far out on the ledge, almost directly opposite Hanover Point, is a series of five footprints from a relatively small herbivorous dinosaur. The strides appear short, so we could imagine perhaps a juvenile Iguanodon casually strolling past. Sadly, along this trackway, one of the footprints is notably absent, because it was recklessly removed some years ago with a rock saw. This gaping square hole served to remind us about the importance of responsible collecting and why we must always observe the fossil code and SSSI restrictions, to preserve specimens for all to enjoy and discover.
We would like to extend our warmest gratitude to everyone who attended the Isle of Wight weekender. It was a pleasure to spend the time with such an enthusiastic and dedicated group of fossil hunters. We hope you all enjoyed, learned and discovered. And congratulations again to the Yan family for winning the coveted Golden Hammer on the UKAFH quiz.
Natural History Museum – behind the scenes January 29th 2018
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.
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.
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 http://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.
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.
*The AMC’s opening hours are 10-12 and 2-4pm Monday to Friday, and the first Saturday of the month.
The Royal Institution lecture – Jurassic Britain: Rediscovering dinosaurs and ichthyosaurs.
I’m pretty sure I’m the only person in the room who isn’t accompanying children. The awaiting audience are chatty and excited. The child behind me already knows what most of the fossils on the table awaiting description are. “Baryonyx claw!” is exclaimed. “What is the word for fossil poo?” encourages dad. “Coprolite!” the excited boy declares loudly.
It is Friday 2nd February and palaeontologist and UKAFH patron Dean Lomax is about to take us on a journey back to the amazing British finds that sparked the original dinomania in the 1800s. From the ‘invention’ of dinosaurs to the great granddad of T. rex, he reveals British dinosaur and ichthyosaur discoveries, including recent identifications of new species and some incredibly rare finds.
The Royal Institution event, Jurassic Britain: Rediscovering dinosaurs and ichthyosaurs, welcomed all ages but was specifically aimed at ages 7+. These are children who know their dinosaurs and who, with encouragement for and enrichment of their passion, might become the next generation of palaeontologists.
Dean begins thus: Before Jurassic World and Jurassic Park was Jurassic Britain. This inspired him as a child to pursue palaeontology as a career. And it’s been quite a career so far, including authoring the outstanding book, Dinosaurs of the British Isles, along with Dr Nobumichi Tamura, on which this talk draws.
Dean captivates his audience with tales of Victorian gentlemen and scholars who strove to understand and describe the mysterious fossil bones that were being discovered, which were found to have some similarity to lizards and led to the term “dinosaur” being coined by Dr Richard Owen in 1842. Yes, dinosaurs are a British invention! Indeed, the first three dinosaurs ever described were British and because we were at the forefront of this new science as well as possessing a large number of dinosaur fossils, Britain had a good many “firsts’ in the record books of dinosaur discovery. Our unique geology means that around 60 dinosaur species are known in Britain from across the whole of the Mesozoic era, making up over 4% of all dinosaurs.
Dean talked us through the timeline of momentous discoveries, amply illustrated with images, artists’ reconstructions, video footage, genuine and replica specimens and visualiser displays. It has been quite a journey from Victorian times to today, as the poorly-understood fossils were imagined and brought to life as the Crystal Palace dinosaurs which are distinctly inaccurate by modern standards as the science of palaeontology has grown and drawn upon other disciplines to understand the fossils and many, many more specimens have been discovered and compared.
We then proceeded on a journey through the British Mesozoic, introducing many notable British dinosaurs, many of them ground-breaking discoveries at the time. From the Isle of Skye to the Isle of Wight we encounter British dinosaurs large and small, complete and fragmentary, early to late, carnivore, herbivore and pecscivore! We travel overseas too, finding examples of British dinosaur and marine reptile fossils in far-flung corners of the globe. Indeed, Australia’s first dinosaur, Agrosaurus, later transpired to be a Thecodontosaurus fossil from Bristol!
The topic of migrating fossils was prominent in Dean’s continuation into Ichthyosaurs, his personal specialism. Ichthyosaurs are not dinosaurs but marine reptiles, having a common ancestor which predates the emergence of the dinosauria. Dean’s own “evolution” as a palaeontologist is closely tied to marine reptiles through his early fieldwork in Wyoming to volunteering in his local museum and discovering an exceptional genuine fossil ichthyosaur in the collections which was thought to be a cast! Dean’s subsequent work describes a journey of hunting down “lost” British fossils hidden away in archives, small museums and overseas, re-examining them and, in two cases, recognising new species. It is a tale of caveats: many fossils are repaired, enhanced or even composites, giving the appearance of a complete specimen but being scientifically inaccurate.
Once Dean had completed our journey from ancient to modern times via the Victorian, questions were invited from the audience. I’m not sure if I was more impressed by the quality and diversity of the questions from the rapt young audience or the fact that Dean could answer them all! Could T-rex jump? Probably, but if he landed badly he might struggle to right himself and a bad fall resulting in a broken limb could prove fatal so he likely didn’t risk it. I’d never considered the question and I’m fascinated by the answer!
I’d like to thank Colin Tucker at the Royal Institution for sending me a ticket to the event.
If you’d like to read more from Dean about British dinosaurs Dean’s article for Deposits magazine is here:
Dean Lomax is an internationally recognised multi-award-winning palaeontologist, science communicator and author. He has travelled the globe and worked on many fascinating projects, from excavating dinosaurs in the American West to describing new species of extinct marine reptiles. Dean is passionate about communicating palaeontology with the public and regularly appears on television, including as series advisor and expert co-presenter for ITV’s Dinosaur Britain. He has written two books, numerous scientific papers, and many popular articles. Dean is a Visiting Scientist at The University of Manchester and patron of the UK Association of Fossil Hunters (UKAFH).
Fossil Hunt at Aust January 14th 2018
On 14 January, UKAFH commenced its packed 2018 schedule with a long-awaited return to Aust in Gloucestershire.
Aust is a small village preceding the Severn River Crossing into Wales. From here, you can access the River Severn foreshore, and the iconic red and grey cliffs visible to commuters travelling from the Principality. The slipway from which access is gained to the foreshore was under maintenance for much of 2016 and 2017, so UKAFH had not led a hunt here for over two years – it was good finally to be back. And, as if we were all sticking to our new year’s resolutions, the hunt was perfect – great finds, great weather and a great group of intrepid fossil hunters.
We began with an explanation of the geology and were shown examples of likely finds by hunt leader, Lee-Anne Collins, and support leader, Sam Caethoven.
The cliffs either side of the Severn Crossing’s huge concrete plinths are visually impressive and illustrate a period of coastal transition, some 221-201myrs ago during the late Triassic. The towering red mudstone of the Branscombe Mudstone Formation represents a 15myr period of seasonal lacustrine deposition in which the depth and salinity of an ephemeral lake fluctuated dramatically. This is evident in the streaks of white evaporite gypsum that stutter throughout this section of the cliff. The environment was hypersaline and inhospitable, that is, an environment not suited to macrofauna and, as such, is unfossiliferous.
Above the red mudstone sits the Blue Anchor Formation. Although this green-grey mudstone represents a time of better sustained water level in a lake or lagoonal environment – evidence of an advancing shoreline – it was still hypersaline and so devoid of macrofossils. It is above these strata, at the base of the Westbury formation, where the fossils we hoped to find exist. At the base of the shale and limestones of the Westbury Formation is the Rhaetic Bonebed – a green-grey calcareous siltstone conglomerate about 205myrs old, which, in contrast to the underlying strata, is incredibly fossiliferous. The Rhaetic Bonebed represents a marine environment, which was shallow, brackish and subject to strong tidal currents and/or storm events. This is evident in the conglomerate nature of the deposit and disarticulation of vertebrate fossils, which commonly include the teeth and bones of fish, sharks and marine reptiles, such as ichthyosaurs and plesiosaurs. Although marine life was clearly profuse, the seafloor was anoxic (without oxygen), aiding the preservation of fossils, which is most notable in the accumulation of coprolites. The bonebed is about 15cm thick, so represents a relatively quick but dramatic coastal transition. Later in the Westbury Formation, the sediment becomes more homogenous, representing a less turbulent marine environment, while the seafloor becomes more hospitable, shown by the abundance of bivalves and the bioturbation of sediment dwelling organisms.
The bonebed is, however, inaccessibly high in the cliff and so we had to hope for recent rockfalls to have bought this highly fossiliferous layer to the foreshore. On this occasion, we were in luck. Some large boulders had recently fallen, while smaller pieces and isolated fossils from the bonebed were easily found amongst the shingle.
As we headed east along the foreshore, it was not long before finds were made. Mary Bite began proceedings by finding a remarkably large Severnichthys tooth – Severnichthys is a large, predatory fish named after the River Severn along which its teeth are often found. Soon, most attendees were finding examples of bonebed, which contained a plethora of fossils, including tiny fish and shark teeth, isolated bones and copious coprolites. As we approached the concrete plinth of the Severn Crossing, Mike Greaves found an Hybodus shark’s tooth, again, of remarkable size.
We carefully made our way around the concrete plinth to the east side of the bridge, where some large sections of bonebed had recently fallen. By breaking up these blocks, many
fantastic fossils were found, including several Hybodus fin spines and beautifully ornamented fish scales. It is possible to treat rocks from the bonebed with vinegar to extract the fossils they contain – placing the rock in a sealed jar containing white vinegar of 6-7% and replacing the vinegar every few days will dissolve the rock. Sieving the sediment at the bottom of the jar will yield dozens of isolated teeth and scales, which you can observe in detail under a microscope or magnifying lens. However, it is worth noting that coprolites and bone often become fragmentary during this process. As the hunt drew to a conclusion, Mike Greaves made a rare and exceptional find in the form of a large Severnichthys jaw section, which clearly contained a number of large teeth. Mike is in the process of very carefully prepping and preserving this fragile specimen, and we hope to keep you updated about his progress on our Facebook page.
Thank you to everyone who joined us for our first fossil hunt of 2018. It was a truly great start to the year and it was great to meet so many new fossil enthusiasts. We hope to see you all again soon on another fantastic fossil foray.
Fossil Hunt at Isle of Sheppey, 12th Nov 2017
On Sunday 12th November UKAFH met in Warden, a small town on the Isle of Sheppey in Kent for the last UKAFH fossil hunt of the year.
Along the East coast of Sheppey is the largest exposure of London clay in the UK stretching over 6km from Warden to Minster on Sea. The London clay is a marine deposit roughly 52 million years old at this location, of the Eocene epoch. The fine sediment was deposited in a fairly deep, warm and placid sea which was relatively close to land – evident in the abundance of wood and plant remains and occasional but rarely terrestrial birds, mammals and reptiles.
After a fantastic explanation of the local geology and palaeontology by Sam Caethoven and a show and tell of some exceptional specimens by Eliott Mills, we were off in search of fossils!
We were bombarded by a strong, bitterly cold arctic wind but fortunately it was not long before we made some great finds. Lucy was first off the mark with a beautiful shark vertebra, found just a few hundred yards from the carpark. Gastropods, bivalves, nipa fruit and shark teeth were all found within a short time on the beach. We soon headed further north along the beach, staying clear of the tall clay cliffs which are particularly dangerous at the moment as large clay blocks are falling frequently – The site is prone to extreme erosion, most evident by the world war two pill boxes which once sat atop the cliffs but are now haphazardly strewn on the beach in front of us. Beyond the pill boxes, the great finds just kept coming. Numerous crab specimens in phosphatic nodules were collected, some of which were exquisitely well preserved. Shark teeth, ray teeth and fish vertebra were also abundant. Eliott Mills made the exceptionally rare discovery of a leaf preserved in clay.
The relentless biting winds made hunting tough, but we endured and were rewarded for our hardy nature. Thank you to everyone who attended, it was a great day and I hope you all thoroughly enjoyed yourselves!
See you all again in the New Year!!
UKAFH weekender at Folkestone and Samphire Hoe, Kent 14th and 15th October 2017
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.
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- Anahoplites ammonite found by Joanna Applegate
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- Anahoplites ammonite found by Eddy Miles
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.
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- Sieving for fossils
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- Large shark tooth find
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!
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- Joanne’s selection of finds
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- Jahaan’s ammonite
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.
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- Shark vertebra found by Joanna
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- Isabelle’s sand tiger shark tooth
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.
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- Sindia’s Euhoplites nitidus
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- Anahoplites planus
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!
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- Swordfish tooth found by Brian Allen
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- Fish tooth found by Sam Caethoven
By the end of the day we had a really great selection of finds amongst the group!
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.
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- White cliffs of Dover
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- Looking towards Samphire Hoe
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.
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- Echinoid in flint block
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- Huge clam found by Chris Tait
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.
