Tag: Fossil

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A shark’s tale

Following the completion of our Life, As We Know It redisplay project earlier this year, we are taking a look at some of the exceptionally skilled people who helped to bring it all together. In this article, model maker Jeremy Hunt and our Vertebrate Palaeontology Collections Manager Emma Nicholls take a deep dive into what we believe is the world’s first 3D reconstruction of the extinct shark Ptychodus as an open water predator…

In six of our newest displays, fossil material found in and around Oxfordshire is used to reconstruct ecosystems from slices of geological time. One of these recreates a marine environment of the Cretaceous Period, between 94 and 84 million years ago, when most of northern Europe was submerged under a warm shallow sea. In these seas swam a formidable 8-metre long shark called Ptychodus.

Until recently, Ptychodus remained something of a mystery: teeth and vertebrae were the only remains scientists could use to work out what it looked like. Its robust, low-domed teeth are covered in deep ridges of enamel that created a mosaic in each jaw. They were capable of crushing shelled prey like a giant nutcracker. Similar teeth in modern sharks are found only in slow-moving species that prowl the seabed, so it was presumed that Ptychodus behaved in the same way.

Fossils of Ptychodus teeth in the new display

But then in 2024 an incredible fossil with much of the animal’s soft tissue preserved was published by Dr Romain Vullo and co-authors. This new fossil revealed clues to the shapes of the fins and their position on the body. The study concluded that Ptychodus was in fact not a bottom-dwelling animal at all, but much more likely to be a fast, agile predator living higher in the water column, and perhaps related to the Great White Shark.

Armed with this recent discovery, we decided to create a three-dimensional model of the reimagined Ptychodus for our Cretaceous display. It had to be a quarter of life-size to fit it in the showcase, but would still be a huge two metres long.

Digital 3D model of a shark, shown in grey, without any skin colouring or texture. The mouth is open and inside is an ammonite being crushed by the shark's plate-like teeth.
An early computer model of the shark and ammonite

“In discussion with Dr Vullo and others we began to decipher the shark’s possible appearance,” says Emma.  “Aspects to sink our teeth into included the skull shape, how it would have fed on hard-shelled free-swimming prey such as ammonites, how the mosaic of teeth sat in the mouth, as well as where and what shape the fins would have been.”

The next stage was to turn these ideas into a realistic model, and for this we turned to specialist model maker Jeremy Hunt. “When I was asked to make the reconstruction of Ptychodus I thought it was a great opportunity to incorporate modern digital techniques and processes that would give great accuracy, but also and flexibility so that adjustments could be made at later stages. This would be really difficult using a traditional clay sculpting approach,” he explains.

Together, Emma and Jeremy began to translate the shark fossil research into draft models on the computer, digitally sculpting versions on-screen. As well as being scaled down to quarter size, the position and pose of the model also needed to work inside the showcase structure and the designs of the rest of the display. Combining computer models helped us to make sure that Ptychodus would fit perfectly and that its method of support could be worked out well ahead of installation.

Digital 3D model of a museum showcase design, shown in grey, without any colouring or texture. The model shows a woman for scale, indicating the case is around 3 metres wide and 2 metres tall. In the case are the modelled contents of the display, including a large shark model.
Digital 3D model of a shark, shown in grey, without any skin colouring or texture. The mouth is open and inside is an ammonite being crushed by the shark's plate-like teeth.
Digital 3D model of an ammonite, shown in grey, without any colouring or texture. The same model is shown from three angles of rotation from side on to almost edge-on, showing the spiral form of it's shell.

To give us a sense of how the final model would actually look, Jeremy 3D-printed little maquettes just a few centimetres long. On these we could check that the anatomy and pose were just what we needed. The maquettes also showed how the shark would be suspended in a diving angle, chomping down on an ammonite which Jeremy was modelling separately, in collaboration with Ricardo Pérez-de la Fuente, a researcher here at the Museum.

A hand holds out a wooden plinth, painted blue, onto which a 3D printed shark model is mounted on a vertical metal rod. The 3D print is also blue and is approximately 15cm long.
3D-printed maquettes of the model helped us to check its form and pose

Once ready, the model was 3D-printed at its display size of two metres long, allowing Jeremy to create a silicone rubber mould to produce a fibreglass cast of the final structure. Fibreglass is both strong and light, perfect for the display. But the model really came to life when Jeremy hand-painted and airbrushed its colourings and markings based on a research by Emma and a concept drawing by palaeo-artist Julius Csotonyi.

A workshop scene showing a silicone model of shark's body cut into two halves lengthways and laying on a workbench. The interior of the mould is light grey and the exterior is light blue.
A fibreglass shark model mounted on a stand almost vertically, with its head at the top of the image. In the background is workshop.
A fibreglass shark model mounted on a stand horizontally, positioned upside down with its underside upwards. with its head at the top of the image. In the background is workshop.
A fibreglass shark model mounted on a stand horizontally, wrapped in a clear plastic. In the background is workshop.
A set of timber beams set a right angles, acting as a frame to carry a model sitting between them. The model is not visible directly as it is wrapped in plastic packing material including bubble wrap.

Once Ptychodus and the rest of the display were installed, the ammonite was placed in the mouth. It is held safely there by hidden strong magnets, caught permanently between those crushing plates, about to become shark food.

Museum exhibit showing a 2 metre long shark model against a backdrop artwork of an ocean containing drawings of other sharks, fish, ammonites and belemnites in the sea, along with corals, shellfish and lobsters on and burrowing into the seabed. Below this scene are a selection of chalk fossils. On the left the title panel is printed on blue acrylic and shows the display's name as 'In the shadow of a shark'.
The Ptychodus model in the final display at the Museum

“This was a great project to be involved with, and I hope the new displays will be enjoyed by all who visit the Museum,” says Jeremy.

Jeremy Hunt, model-maker

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See more of Jeremy’s work at: www.instagram.com/memsculpt

Dr Ross Anderson climbs a steep, green slope surrounded by pine trees and dramatic mountain scenery.

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Oxford team’s fieldwork revealing how complex life first evolved on Earth 

By Ross Anderson

In Summer 2024, a team of palaeontologists and geologists from the University of Oxford, along with colleagues from Dartmouth College, the University of Washington, and Williams College in the USA, undertook an expedition to the Little Dal Group in the Mackenzie Mountains, Northwest Territories, Canada. Our purpose was to uncover some of the oldest fossil ecosystems that record complex life.

A helicopter parked on a makeshift wooden platform surrounded by fuel drums, with gear and personnel preparing for departure in a remote area.

Photo: Robert Gill
Photo: Robert Gill

Complex life comprises all organisms whose DNA is enclosed in a cell nucleus. This includes animals and plants but excludes bacteria. Today, this complex life accounts for most of the Earth’s biomass, documented biodiversity, and oxygen production. Understanding when and how it first evolved remains one of the central unanswered questions in evolutionary biology.

Two geologists collect rock samples from a cliff in a mountainous area, with rugged peaks in the background.
Photo: Robert Gill
Dr Ross Anderson walks across a rocky, barren valley under a clear blue sky.
Photo: Robert Gill

As palaeontologists, we normally use fossils to reveal the history of life. Fossils tend to preserve larger animals with hard shells or skeletons—creatures such as trilobites, ammonites, dinosaurs, and mammoths. However, the first complex organisms were microscopic and lacked such hard parts. As a result, their soft and fragile cells rarely fossilised. Put simply, we have found it a major challenge to trace the origins of complex life with fossils.

Dr Ross Anderson climbs a steep, green slope surrounded by pine trees and dramatic mountain scenery.
Photo: Robert Gill
Dr Ross Anderson wearing outdoor gear examine a rocky cliff face, one using a small tool to collect rock samples.
Photo: Robert Gill

I have argued that finding rocks made up of antibacterial clay minerals holds the key. These minerals can slow the decay of organic cells long enough for them to survive as fossils. The Little Dal Group contains ~900-million-year-old rocks that are rich in just such clays, making it a prime target for new fossils that might help us unravel the origins of biological complexity.

Close-up of hands holding a slab of dark shale rock with faint fossil-like impressions.
Photo: Robert Gill
Organized rows of white sample bags with geological samples with yellow labels laid out on rocky ground.
Photo: Robert Gill

I was joined in Canada by my DPhil student, George Wedlake, from the Department of Earth Sciences. Together we spent two weeks collecting over 100 rock samples. The samples record an ancient tropical sea not unlike the Bahamas today, where early complex life likely flourished.

Back in Oxford, at the Museum of Natural History, George and I are now examining the samples; dissolving the rocks with hydrofluoric acid to extract and study the tiny fossils. We hope these new fossils will transform our understanding of how complex life first took hold on our planet.

Our fieldwork was funded by a Royal Society University Research Fellowship and by the Oxford NERC Environmental Science Doctoral Training Partnership. It was conducted under permit and with the support of the Sahtú Dene people.

The outside and inside of a box, showing its contents

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Boxes, Bags, and Bones

NO, THERE WEREN’T HARMONICAS IN THE JURASSIC!

Looking through the collections at OUMNH never gets boring, but sometimes a drawer will open up to reveal something even more eye-catching than the fossils usually found inside. Whilst working on the Museum’s Jurassic marine reptiles a few weeks ago, I came across something particularly surprising: a jewel-green box with a fantastic piece of art on the front. I was instantly intrigued and reminded of all the other times I had encountered a holder as fascinating as the specimen inside it.

Storage in museum collections is an ongoing pursuit of balance between ideal environmental conditions, specimen accessibility, and efficient use of space. This balance applies to all levels of storage: from building to room, cabinet to specimen tray. OUMNH’s Earth Collections are stored in conservation-grade, acid-free boxes or trays made of plastic or cardboard. These boxes are sometimes layered with low-density foam or ‘plastazote’ which can be carved to fit the specimen and keep it from being jostled or damaged. Holders with lids can also provide a micro-environment for specimens to help minimise their exposure to changes in humidity and temperature. The use of these standard materials not only helps protect specimens from degradation but can also deter pests from harbouring in collections spaces.

However, historical collections like those at OUMNH may retain holders that are not standard use. Sometimes, a clean and empty plastic Ferrero Rocher box is the perfect size for that small mammal skeleton that needs storing! Other times, an unusual holder might have been the only thing a field collector had on hand to transport a specimen to the Museum.

A harmonica box containing pliosaur teeth, a marine reptile that lived during the Jurassic (145.5 million – 201.6 million years ago).

One example of an unusual specimen holder is this ‘Echo Harp’ box by pre-eminent German harmonica manufacturer Hohner, likely from the 1960s. The box no longer holds a harmonica, but instead accompanies pieces of Jurassic pliosaur teeth from Weymouth, Dorset. Pliosaurs were a kind of carnivorous marine reptile related to plesiosaurs, with four flippers, and long tails and necks. If they hadn’t gone extinct in the Cretaceous-Paleogene extinction event 66 million years ago, perhaps they would have come to appreciate the harmonica and its artistic packaging!

Aside from their artistic value, museums may sometimes retain unusual holders because they contain primary source information on the specimen. One such example is a ‘Bryant and May’s Patent Safety Matches’ box in our Earth collections, bearing a packaging design from the early 1900s. The box actually houses a chicken tarsometatarsus bone excavated from “High St. New Schools” in Oxfordshire and is accompanied by a label which describes the particular layer of gravel the specimen was found in — important information for any archaeological or palaeontological find. Although the specimen is stored alongside Pleistocene fossils (10,000 – 2.6 million years ago), chickens did not originate in the UK, so the bone is likely from much more recent times. Someone still must have thought it was important enough to keep in its own special holder!

A Tate and Lyle sugar bag containing a Jurassic specimen, with handwriting on the outside describing the stratigraphy the fossil was found in.

Similarly, this ‘Tate and Lyle Granulated Sugar’ paper bag features a handwritten original notation in blue pen on the outside. The bag originally contained a specimen found in a collection of Jurassic gastropods and bivalves from Somerset, with the handwriting describing the fossil’s stratigraphic information. The bag also features a recipe for cinnamon apples on the reverse, which we have yet to try!

A wooden box and the Quarternary fossils (up to 2.6 million years ago) it originally housed. An accompanying letter describes the delivery of the fossils to William Buckland, Oxford University’s First Reader in Geology.

In addition to primary source information, original holders may also provide specimens with provenance. This ovular wooden box filled with organic stuffing material originally contained Quarternary fossil specimens found in Peak’s Hole, Derbyshire. The Museum archive also holds a handwritten letter describing the specimens inside the package and how they were found. The letter dates to 1841 and is addressed to Oxford University’s first Reader in Geology, William Buckland.  The specimen holder forms part of a group of objects with such a strong interconnection, and such strong documentation, that retaining the box is a matter of course.

All in all, it’s great that we’ve come so far in the advancement of safe and stable housing for specimens. At the same time, it’s always fascinating to see what else has made its way into collections, just by nature of being able to hold things, either for a short time or a long one. Despite living in the Earth Collections – among fossils, rocks, and the geological past – these objects offer us a little bit of human history too.

By Brigit Tronrud, Earth Collections Assistant

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A GUT FULL OF SAND

UNEARTHING THE PECULIAR EATING HABITS OF A TRIASSIC MAYFLY SPECIES

During the summer months, the beaches of Mallorca offer an irresistible draw for tourists and palaeontologists alike. Visitors to the small Spanish island find themselves lured by its glittering seas, captivating coastline, and tasty white sands…

…well, tasty for some, at least!

Coastal cliffs near Estellencs (Mallorca, Spain). Palaeontologists working here discovered fossils of Triassic mayfly nymphs with unusual gut contents. (photo: Balearic Museum of Natural Sciences)

Following recent fossil excavations near the the coastal town of Estellencs in southwest Mallorca, palaeontologists have discovered evidence of a species of mayfly with a pretty peculiar diet. The mayflies in question lived 240 million years ago in bodies of water associated with ancient floodplains. Some of the juvenile mayflies (nymphs) were so well-fossilised that it has been possible to study the contents of their guts. A research team, led by Dr Enrique Peñalver, and featuring OUMNH’s own Dr Ricardo Pérez-de la Fuente, discovered that the mayflies’ digestive tracts contained a mixture of detritus (the decomposed remains of other organisms) and particles of a type of rock known as claystone. The most likely explanation for this strange food-pairing? It seems that the nymphs actually survived by eating muddy sediments that had settled to the bottom of the swampy-waters they lived in – yum!

If you’ve ever tried eating a sandwich on the beach, you’ll be familiar with the feeling of sand in your teeth. The sharp crunch of mineral sediment is worth the sacrifice for the delicious, digestible portion of your sandwich – the bread and fillings. Animal digestive systems are unable to extract energy from inorganic mineral matter, like sand. Instead, we rely on organic material for nutrition, i.e. matter derived from plants and other animals. It seems that the Triassic mayfly nymphs found in Mallorca would have munched through large quantities of sediment; digesting the organic detritus it contained, and excreting the inorganic remainder.

One of the numerous Early Triassic mayfly nymphs from Mallorca preserved with gut contents. These inclusions result from the original sediment the nymphs fed on (cololite, labelled here with arrows). Image adapted from Peñalver et al. (2023).

Sediment-based diets are extremely rare among living insect species. A handful of modern mayfly species have been observed to munch on the muddy sediment that surrounds the openings of their tunnels, but this is a very rare occurrence. Sediment is a pretty challenging food source, and it’s hard to say why insects may have relied more heavily on it in the ancient past. It is possible that the mayflies found in Mallorca adopted their diet as a result of the Permian mass extinction, which killed off more than 80% of all the species on Earth, ‘just’ five million years prior. With fewer choices of organic material available to eat, perhaps the mayflies were left without a better choice? Or maybe they were simply exploiting new environmental niches that opened up in the aftermath of this catastrophic event?

One of the reasons why it is so difficult to theorise about the evolution of species following the Permian mass extinction is the dearth of fossil evidence dating from the period. Luckily, the coastal cliffs of Mallorca can offer us a rare, exciting glimpse into some of the ecosystems that existed ~247 million years ago. The research team behind the Mallorcan mayfly discovery have also used fossils from the same site to describe the world’s oldest-known dipteran (a group of insects including flies, mosquitoes, gnats, and midges), naming the species Protoanisolarva juarezi. These flies would have lived on land, in back swamp areas, rather than in the water. However, much like the Triassic mayfly nymphs, they would have fed on detritus, and played a key role as recyclers of organic matter in these ancient ecosystems.

The larva of the oldest-known gnat, 247 million years old, was found near Estellencs in Mallorca. (Image: CN-IGME CSIC).

It is by paying attention to tiny insect fossils like these that we might hope to find answers to one of the biggest questions in palaeontology: how did life rebuild in the aftermath of our planet’s worst mass extinction? And what might this teach us about ecosystem responses to future mass extinction events?

By Ella McKelvey, Web Content and Communications Officer

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Reindeer are not just for Christmas

WHAT WE CAN LEARN FROM BRITAIN’S ICE AGE RANGIFER

By Emily Wiesendanger, Volunteer

If you’ve ever visited the Skeleton Parade in the Main Court of the Museum, you may have noticed that nestled between the Malayan tapir and the rhinoceros is the skeleton of a reindeer, or caribou if you are from North America.

Today, reindeer are found throughout the Arctic and Subarctic in places like Canada, Alaska, Russia, and Lapland (Norway, Sweden, and Finland). However, their range was not always so limited. During the Late Pleistocene – around 126,000 to 11,700 years ago – it would not have been unusual to see herds of reindeer roaming freely across most of Britain and western Europe. In fact, reindeer sub-fossils in the form of bones, teeth, and antlers have been found at a number of Oxfordshire sites including the excavations at Cassington and Sutton Courtenay, which are kept behind the scenes in the Museum’s extensive Paleontological Collections.

Studying these Ice Age reindeer can teach us as much about the future as they can about the past. Pleistocene reindeer were likely similar to their modern counterparts, which undertake large, bi-annual migrations between summer and winter grazing pastures. Looking at the movements of Ice Age populations of reindeer can therefore help us to understand how modern reindeer may respond to climactic and environmental changes in the future. This is possible because reindeer only come together in large herds at certain times of the year. During these seasonal aggregations, the herd is characterised by different combinations of ages and sexes. Therefore, by looking at the age and sex of the remains of reindeer present at a site, we can tell the time of year that they were left there — in particular, we can infer the sex of reindeer from their bones, their age from their teeth, and their age and sex from their antlers.

Modern reindeer are highly adapted to cold environments (-45 to +15°C) with two layers of fur (the tips of which turn white in the winter), short and furry ears and tails, and large feet to make walking on snow and digging for food much easier. Reindeer even make a clicking noise with their feet, produced by a tendon slipping over a bone, to help keep track of each other in blizzards or fog.

Unfortunately, it is extremely rare to find anything so complete as the reindeer in the skeleton parade. Instead, you are much more likely to find remains like the antler below, which was excavated from Sutton Courtenay. Despite being only a fragment, it is exactly this kind of sub-fossil that can help us to understand more about the movements of reindeer during the Late Pleistocene.

This left antler base and skull from a male reindeer found at Sutton Courtenay can be used to determine which season reindeer were present at the site.

Reindeer grow and shed a new pair of antlers every year, and this happens at different times of the year for males and females. If you can identify whether an antler is male or female, shed or unshed, you can also tell the season of death. The Sutton Courtenay antler featured above would have belonged to a male reindeer. At its base, we can see it is still clearly attached to some skull bone, and so is unshed. Because males only have their fully grown antlers between September and November, this particular reindeer must have been in the area around Sutton Courtenay during the autumn. It is by using similar deductions that we can also tell that Rudolph and his antlered friends would have actually all been females — by the 24th December, males have already shed their antlers, but females will keep them until the spring!

After studying thousands of these kinds of remains from all over Britain, we can start to build a picture of where reindeer were at different times of the year. It’s amazing to think that we can learn so much from simple skeletons. So, the next time you visit the skeleton parade, take a moment to think about the secrets they may be hiding.

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Reading Archival Silences

MAUD HEALEY AND HER GEOLOGICAL LEGACY

By Chloe Williams, History Finalist at Oxford University and Museum Volunteer

Email: chloegrace1000@gmail.com

“The professor regrets to have to record the loss of the invaluable services of Miss Healey, who as a result of overwork has been recommended to rest for an indefinite period. This will prove a serious check to the rate of progress which has for some time been maintained in the work of rearrangement, and it is hoped that her retirement may be only temporary.” So ends the Oxford University Museum of Natural History’s 1906 Annual Report, marking the near-complete departure of Maud Healey from the archival record.

Despite how little of her history has been preserved, it is clear that Maud Healey made significant contributions to the field of geology. After studying Natural Sciences at Lady Margaret Hall in 1900, Healey worked at the Museum as an assistant to Professor William Sollas from 1902–1906. Here, she catalogued thousands of specimens and produced three publications. These publications were at the centre of debates about standardising the geological nomenclature, and turning geology into a practical academic discipline that could sustain links across continents. However, Healey was continually marginalized on the basis of her gender. Closing the Geological Society of London’s discussion of one of her papers, “Prof. Sollas remarked that he had listened with great pleasure to the complimentary remarks on the work of the Authoress, and regretted that she was not present to defend before the Society her own position in the disputed matter of nomenclature.”[1] Predating the Society’s 1904 decision to admit women to meetings if introduced by fellows, Healey had been unable to attend the reading of her own paper.

Photo of the Geological Society of London centenary dinner in 1907, at which Maud Healey was present. Healey can be seen seated in the fourth row from the front, three chairs to the left. Of the 263 guests, 34 were women, 20 of whom were the wives or daughters of academics, and only 9, including Healey, were present ‘in their own right’. [2] Source: Burek, Cynthia V. “The first female Fellows and the status of women in the Geological Society of London.” Geological Society, London, Special Publications 317, no. 1 (2009): 373-407.

Healey later worked with specimens collected by Henry Digges La Touche in colonial Burma (now Myanmar). While Healey worked with the identification of species, acknowledged by La Touche himself as ‘a more difficult lot to work at’ than similar specimens assigned to her male contemporaries, the physical collection and therefore its name and record is attributed to a male geologist. [3] She continued her work identifying La Touche’s collection of Burmese fossils after retiring from the Museum in 1906 and published a report about them in 1908. What happened to her afterwards is unclear. Tantalizing snippets like a 1910 marriage record might suggest that she turned to a life of domesticity, but whether Healey continued to engage with geology as a hobby remains uncertain.

Left: Fossil bivalves from Burma (Myanmar), part of the La Touche collection sorted and identified by Maud Healey. Right: Illustration from Fauna of the Napeng Beds (1908), Maud Healey’s monograph describing the La Touche collection. From the library at Oxford University Museum of Natural History.

It is almost unbelievable that a professional of Healey’s calibre could abandon the work in which she excelled. However, Healey lacked any familial connections to geology, and apparently did not marry into money, which would have made it difficult for her to retain access to organizations like the Geological Society of London. The diagnosis of ‘overwork’ mentioned in the Annual Report makes it possible that a medical professional could have discouraged her from engaging further in academia. Unfortunately, any diaries or letters which might have provided us with further clues were not deemed worthy of preservation.

Maud Healey on a dig site (location unknown). Image from the Archives at Oxford University Museum of Natural History.

Tracing Maud Healey’s history to 1910, it might seem as though we hit a depressing dead end. Healey is one of many nineteenth-century female geologists who participated in an international community in a range of roles including collecting, preserving samples, and actively producing knowledge. However, like many of her colleagues, her contributions are largely absent from the historical record. My research doesn’t aim to simply ‘rediscover’ these exemplary women after previously being ‘hidden’ from history, but instead considers how history itself is constructed from a material archive created along lines of gender and class. A subjectivity which surfaces only rarely in appended discussions to academic papers, and in spidery cursive on ancient fossils, Maud Healey ultimately suggests the need for women’s history to read archival silences as their own stories.

Works cited

[1] Healey, M. ‘Notes on Upper Jurassic Ammonites, with Special Reference to Specimens in the University Museum, Oxford: No. I’, Quarterly Journal of the Geological Society of London 60, (1904), p.1-4.

[2] Burek, Cynthia V. “The first female Fellows and the status of women in the Geological Society of London.” Geological Society, London, Special Publications 317, no. 1 (2009): 373-407.

[3] La Touche, H.D. Letter to Anna La Touche, 1 August 1907. La Touche Collection. MSS.Eur.C.258/77. Asian and African Studies Archive, The British Library, London, UK.

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