Tests of time: Foraminifera and Radiolarians in science, art and 3D

Doctoral researcher Elaine Charwat is exploring the value and meaning of models and casts in the Museum’s collections as part of her PhD. She has recently been studying some fabulous models that help to visualise and understand some of the very, very smallest of specimens…

By Elaine Charwat

The first time I encountered a Radiolarian was in a book – Ernst Haeckel’s (1834-1919) weird and wonderful Kunstformen der Natur (Art Forms in Nature, 1899-1904). It took comparative morphology – comparing the shapes of organisms – to new giddy heights, scientifically, philosophically and artistically. I felt that giddiness when looking at page after page crammed with crustaceans, orchids, hummingbirds, moths and even bat faces, all exquisitely arranged to celebrate their symmetries, the evolution and kinship of their shapes and forms. It also made visible organisms that are normally all but invisible.

Illustration of Cyrtoidea (table 31) from Kunsterformen der Natur (1899 – 1904) by Ernst Haeckel. By permission of the Linnean Society of London.

Foraminifera and Radiolarians are microscopic sea-dwelling organisms. Species may be found as fossils dating from Cambrian times, ca. 500 million years ago, right up to living specimens today.

To Haeckel, they were living proof of Darwin’s theory of evolution, and for his own belief that morphology was the key to understand the actual processes of evolution, catching it in the act. However, these organisms had two big disadvantages – their unwieldy taxonomy, or the way they are classified, and their minute size: they were difficult to examine and display.

Illustrations of Radiolarians, (table 28). from Die Radiolarien (1862) by Ernst Haeckel. By permission of the Linnean Society of London.

Through his illustrations, Haeckel widely popularized them – triggering a Victorian craze for microscopes and microorganisms, as well as influencing art nouveau art and architecture. But there were limits to what an illustration could communicate. Models stepped in, representing these organisms in ways illustrations could not.

Detail from Haeckel’s Kunstformen der Natur (1899 – 1904)

One defining feature of Radiolarians and Foraminifera is their shells – called “tests”. Variations in shapes of the tests not only indicate that they are different species, but also, excitingly, provide clues about space and time. The tests of Neogloboquadrina pachyderma, for instance, record ocean temperature over geological timescales – their shells coil to the left when water temperatures are relatively cold, and to the right when it is warmer. The potential for research into climate change is obvious. Foraminifera are also important “signature fossils”, helping geologists to determine geological strata.

You really need to see them in glorious 3D to appreciate these tests across geological time, to understand their complex, beautiful shapes. And I felt a similar twang of excitement to my first encounter with them through Haeckel when discovering these extraordinary models here in the Museum as part of my PhD research.

Václav Frič (1839-1916) was a natural history dealer based in Prague. He developed a series of 100 plaster of Paris models of Foraminifera (1861), as well as the stunning papier-maché models of Radiolaria (listed in his catalogue of 1878). He worked closely with Ernst Haeckel.

A selection of Frič’s models in the Museum’s stores

The Frič models oscillate between visible and invisible, illustration and model, art and science, philosophy and theory. They bear witness to a key period in the history of science when they were used to give tangible shape and proof to Charles Darwin’s poignant phrase:  “[…] from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.”

Through the models we can “grasp” microorganisms that have been around for over 500 million years; organisms that truly have stood the tests of time.

A tale of two seahorses

Real or fake? Do replicas have a value of their own? Elaine Charwat is exploring this in her PhD, using the Museum’s large collection of natural history models and casts to research their role in science. Here she tells the story of the fascinating fish that caught her imagination…

By Elaine Charwat

It all started with a seahorse. Last year, I walked into a little seaside shop, and I spotted a seahorse. I instantly flipped back to the happy day I bought my first dried seahorse as a child, the beginning of a life-long passion for the natural world. The man behind the counter smiled: “It’s a fake.” Really? “3D printed.” It looked absolutely perfect. Tracing its lines with my fingers, I said, “It’s a model”.

Ever since I became interested in models and replications, I have encountered this perception of them as “fakes”. Quite recently, I heard the curator of a natural history museum call the cast of a dinosaur skeleton a “fake”. Models in natural history – and in this I include casts and reproductions – are what the Germans call “Wissensdinge”, objects that contain, distribute and generate knowledge. In this aspect, the real specimen and the model meet. Models are made from a vast array of materials with often astonishing skill and technologies. They represent what we know about a particular organism at a certain point in time. They have a history, a context.

Long live the replica! Most of our most beloved dinosaur skeletons in museums are partly or fully casts of bones, like Stan’s here at the Museum. Almost complete skeletons like Stan’s are extremely rare, and casts allow us to share and preserve them. Accompanying models give the bones “flesh and blood” – and provide a snapshot of what was known about the dinosaur when the model was made.

But they are also ambassadors, and this is something I realised when I held the “fake” 3D-printed seahorse in my hand. While it becomes ethically problematic to buy specimens of organisms like seahorses, something of it is captured, and communicated, in a reproduction. I can still trace its exoskeleton, and marvel at its strange symmetry. This symmetry, incidentally, is being analysed for its potential in robotics. Seahorses have unusual tails – instead of the cylindrical trail structure found in most animals, theirs have a square cross-sectional architecture, resulting in a unique combination of toughness and flexibility. In fact, when studying the unique abilities of the seahorse’s tail, researchers have actually used 3D-printed specimens.

Seahorse from the Museum’s collection. Even in Victorian times, long before 3D printers, there seems to have been a desire to emphasise that souvenir seahorses were “natural” – i.e. not man-made. Was it because seahorses are easily preserved and so attractive when dead and dried?

The Oxford University Museum of Natural History has a largely unexplored wealth of models and casts. Many of them date to the second half of the 19th Century, the heyday of their production. Made from glass, wax, metal, wood, plaster, papier-mâché or, indeed, actual bone and feathers, they were modelled, cast, sculpted, glued, painted and mounted to enhance and preserve our understanding and appreciation of nature. But they also tell of scientific discoveries and controversies, research and teaching, rivalries and collaboration, politics and society, ideas and identities.

Small IMGP5899
Spot the replica – both the specimen and the 3D printed seahorse are “Wissensdinge”, they have a context and provide valuable information.

I will trace these complex relationships in a collaborative and interdisciplinary PhD project called “Nature of Replication”. This is funded by the AHRC and jointly supervised by the Institute of Archaeology, University College London, and the Oxford University Museum of Natural History.

The 3D-printed seahorse now lives alongside my real seahorse. So I like to think of my project as a journey that started with one seahorse, and continues with another.

Is it real? – models, casts and replicas

One of the most common questions asked about our specimens, from visitors of all ages, is ‘Is it real?’. This seemingly simple question is actually many questions in one and hides a complexity of answers. 

In this FAQ mini-series we’ll unpack the ‘Is it real?’ conundrum by looking at different types of natural history specimens in turn. We’ll ask ‘Is it a real animal?’, ‘Is it real biological remains?’, ‘Is it a model?’ and many more reality-check questions. Here’s your final installment…

There’s nothing like standing under a huge T.rex skeleton, staring up at its ferocious jaws, to get the blood pumping. Visitors often ask “Is it real?” and look rather deflated when they find out it’s a cast. So why do we include casts, models or replicas in our displays, if they don’t have the same impact as the real deal? The truth is that they’re valuable additions to museum displays, allowing the public to engage with specimens that would otherwise be hidden behind the scenes.

Please touch! A cast of the famous Oxford Dodo helps visitors explore this fragile specimen.

On any visit to the Museum, you’ll come across labels that tell you the object you’re looking at is a cast. It could be a dinosaur skeleton, a brightly coloured fish, an amphibian specimen or even the head of the Oxford Dodo. But what is a cast? Casts are made by taking a mould of bones, or sometimes whole animals, then filling that mould with resin, plaster or fibre glass to make a copy. They can be incredibly accurate or lifelike.

It’s extremely rare to find whole dinosaur skeletons, and very difficult to mount heavy fossils (weighing tonnes) onto large armatures. Our Tyrannosaurus rex is a cast of the famous Stan, found in South Dakota, USA, and one of the best preserved skeletons of its kind in the world. But the “real” Stan is kept at the Black Hills Institute of Geological Research, so the only way we can offer the breath-taking experience of standing beneath a T. rex here in Oxford is by using a cast.

The Dodo Roadshow in 2015 would have been a lot less fun without our life-size dodo model

Even Stan has some bones missing, so sometimes casts are made up of several individual skeletons. Copies can also be made to give the impression of a more complete skeleton. For example, if a left bone is missing, a mirror of the right hand bone can be created. We call these specimens “composites”.

Animals such as fish and frogs aren’t easy to taxidermy; their skins shrivel, dry out, lose their colour and crack. Painted casts are a good way to show what these animals look like.

A model allows us to show the intricate scales of this Blue Morpho butterfly up close.

Models, such as the giant insects on the upper gallery and the Archaeopteryx in the Evolution of Flight display (at the top of this post), are very clearly not real. These are made by model makers to show something that can’t be seen or shown with real specimens. The giant insects are a way of showing the detail of very small creatures. The palaeontological models show what we think extinct animals might have looked like in life. They’re hypothetical models based on the latest scientific research, which can change very quickly, and always have an element of artistic assumption or speculation in the details.

In this series we’ve talked about taxidermy, skeletons, fossils and more, but these are just a few of the kinds of specimens we have on display. There are also nests, plastinated models, microscope slides and dioramas, which all have a mix of real and non-real elements. When you are looking around the Museum try to think about which specimens are real and which aren’t… and how does that make you think about the specimen?

Read the other posts in the Is it real? series here.

‘Flight’ of the Dodo


By Mark Carnall, Life Collections manager

The museum holds the only remaining soft tissue of the extinct dodo known anywhere in the world. The partially dissected skin of the head and scales from the feet of a single dodo represent one of natural history’s most iconic specimens. In fact, it is so tied to the museum’s identity and history that we use the dodo as our logo and it is even incorporated in the name of this blog.

Although the dodo head had been at Oxford University since the formation of the original Ashmolean Museum in the 17th century, it wasn’t really until the 19th century that the specimen really became celebrated.

Around this time, publications confirmed the extinction of the dodo from the island of Mauritius, where it was endemic. To capitalise on the rising interest in the animal, Ashmolean Museum Keeper John Duncan commissioned a number of casts of the Oxford Dodo head to give to, and exchange with, other museums.

One of the earliest of these casts was presented to the British Museum in 1828; later casts are recorded as being sent or exchanged with leading scientists of the time, as well as with Leiden Museum and the Royal College of Surgeons.

From these original and later casts further casts and models were presumably made, and eventually, dodo specimens spread to virtually every major natural history museum in the world. Today, many museums display casts of this head, all stemming from the single specimen held here in Oxford.

One of the many casts in the Oxford University Museum of Natural History, this one has been painted to match the original specimen
One of the many casts in the Oxford University Museum of Natural History, this one has been painted to match the original specimen

The Museum contains a number of models and casts of the head too; some are made from plaster and resin, some are painted to resemble the original specimen. The head of the dodo was actually dissected in 1847, by Henry Acland. He removed the skin from one side of the face so the early casts are a record of how the specimen would have looked originally.

In preparation for the Presenting display in the Museum I contacted natural history museums through the Natural Sciences Collections Association asking people to share information and photos about their casts and models of the dodo head. I wanted to try and construct a picture of how the dodo head was disseminated, as well as capture the diversity of quality and colours of representations of the original specimen. Here’s how far some of the dodos have flown:

American Museum of Natural History

© Paul Sweet, American Museum of Natural History

Cast of head with no further catalogue information about provenance.

Bradford Museums and Galleries

© Bradford Museums and Galleries

© Bradford Museums and Galleries

Cast of the head labelled as coming from Cartwright Hall. Curator Gerry McGowan suspects this may have come via the Bradford Philosophical Society collections. The first curator of the society, Louis Compton Miall was friends with Thomas Henry Huxley and through him had contacts with many other geologists who may have gifted or exchanged this cast.

Bristol Museum & Art Gallery
Bristol received a cast of the head directly from Oxford from Philip Duncan in 1834, keeper of the Ashmolean Museum between 1826 and 1855. Unfortunately, the head was likely destroyed in bombings of Bristol in 1940.

Canterbury Museum, New Zealand
Received a cast of a head from Professor Rolleston on 21 July 1871 in exchange for two kiwi skeletons which are still in the museum collections today.

Grant Museum of Zoology UCL

Cast of head and foot presented to the museum by E.Ray Lankester in 1891/1892 just after leaving UCL and being appointed the Linacre Professor of Comparative Anatomy at Oxford.
© UCL Grant Museum of Zoology

Cast of head and foot presented to the museum by E.Ray Lankester in 1891/1892 just after leaving UCL and being appointed the Linacre Professor of Comparative Anatomy at Oxford.

Great North Museum Hancock

The Great North Museum Hancock’s cast was presented by George Townsend Fox, this specimen had been presented to the natural History Society of Newcastle in 1841 by Fox and had originally been presented by Philip Duncan.
© Great North Museum: Hancock

The Great North Museum Hancock’s cast was presented by George Townsend Fox. This specimen had been presented to the Natural History Society of Newcastle in 1841 by Fox and had originally been presented by Philip Duncan.

Horniman Museum and Gardens

© NH.64.11 Horniman Museum and Gardens

Cast of the head that had quite a circuitous route to the Horniman Museum. The Horniman received the cast from the geology department of Queen Mary’s University of London in 1964 which received the cast from the Saffron Walden Museum in 1962.

Manchester Museum
Cast of a head, presumed to have been presented by William Boyd Dawkins. The cast is currently on display in the Living Worlds gallery in Manchester Museum.

The National Geological Repository British Geological Survey

© National Geological Repository British Geological Survey

Cast of a head recorded as from the ‘original in the Ashmolean Museum’, purchased from the sale of Gideon Mantell’s collections in 1853.

National Museum of Ireland

© National Museum of Ireland

Cast of head with ‘J.Johnson’ inscribed into the base, possibly referring to John Johnson, who commissioned five casts from the museum in 1837.

Natural History Museum London

© The Trustees of the Natural History Museum London
© The Trustees of the Natural History Museum London

The Natural History Museum’s collections contain three casts of the Oxford Dodo head – two in the ornithology collections (pictured) and one in the palaeontology collections. The unpainted cast in the ornithology collections has the name ‘Johnson’ inscribed into the base.

Nottingham Natural History Museum

© Nottingham Natural History Museum, Wollaton Hall

Colleague Adam Smith got in touch with some interesting specimens from Wollaton Hall. The first one looks like another cast in this series but the second cast is unlike any of the others gathered here. The cast shows an open eye, detail on the beak as well as a more defined hook to the end of the bill.

Unfortunately, there’s not much information about the origins of these two casts so it’s probable that the ‘open eye’ cast may be a cast of a model reconstruction or an in progress sculpt. There’s an extremely slight chance it’s a cast of an otherwise unknown dodo head… If you recognise this dodo head do get in touch so we can solve this mystery for colleagues in Nottingham (it’s not the model dodo that we have on display here!).

Warwickshire Museum

© Warwickshire Museum
© Warwickshire Museum

Cast of a head at Warwickshire Museum with damage to the beak. Donated to the museum by clergyman and naturalist Reverand Andrew Bloxham in the 19th century. As the museum is currently moving stores, further information about when this cast was acquired is inaccessible.


If you work at a museum and have a dodo head cast to share, please do get in touch and we’ll update this blog accordingly.

Last updated: 10/11/17

‘Presenting… The Flight of the Dodo’ was on display at the Museum of Natural History from the 25 January to 22 March 2017.


With many thanks to colleagues across the sector who helped with information and images about dodo specimens: Adam Smith, Alice Adams, Jack Ashby, Carol Davies, Bonnie Griffin, Dan Gordon, Yvette Harvey, Mike Howe, Emma-Lousie Nicholls, Laura McCoy, Gerry McGowan, Nigel Monaghan, Henry McGhie, Pat Morris, Paul Scofield, Paul Shepherd, and Paul Sweet.