Whether you’re a great white shark with a deadly conveyor belt of teeth, a deep sea snail with a coat of armour or a coral building the Great Barrier Reef one polyp at a time, mineralized skeletons are a crucial part of many animals’ way of life. These hard skeletons – shells, teeth, spines, plates and bones – are all around us.
The fossil record is full of the remains of the skeletons of long-extinct critters, so much so that entire layers of rocks can be composed almost completely of them. But this has not always been the case…
Travel back some 570 million years to a time known as the Ediacaran and the picture is very different. Although there were large-bodied creatures that were possibly animals, they were entirely soft-bodied. Then, right at the end of the Ediacaran Period, the first animals with hard skeletons evolved, creating strange tubes, stacked cones, and other bizarre forms such as Namacalathus, which resembles a baby’s rattle!
In the following few tens of millions of years, in the early part of the Cambrian Period, a whole host of animals burst onto the scene baring their ‘teeth’, hiding in their shells, and bristling their spines. In fact, we can trace the origin of almost every kind of animal skeleton to this relatively short window of the Earth’s past.
In my research, I have compiled the evidence for how and when these skeletons first appear. Three key observations have emerged. First, skeletons evolved independently many times in different animal groups. Second, there is both direct and indirect evidence, such as exceptionally preserved fossils and trace fossils, for entirely soft-bodied examples of animal groups that later evolved skeletons. And lastly, the first animal skeletons are less complex and more variable than later examples.
Added to what we know about how living animals build their skeletons, this all points to one explanation: Animal skeletons evolved independently in different groups by utilising a common ‘toolkit’ of genes, inherited from their common ancestor but used in different ways in different skeletons.
In other words, the soft-bodied ancestors of animals with hard parts had inherited all they needed to build simple skeletons that were then honed into the array of shells, teeth, spines, plates and bones we see today. For these skeletal pioneers, armed with their genetic ‘toolkit’, the environmental and ecological pressures of the early Cambrian prompted the evolution of similar, but independent, responses to their changing world – when life got hard.
Murdock, DJE. 2020. The ‘biomineralization toolkit’ and the origin of animal skeletons, Biological Reviews, is available for free here.
Top image: Tiny fragments of early skeletons, shells and spines, from around 510-515 million years ago.
With our Life, As We Know It redisplay project now underway, our Senior Archives and Library Assistant Danielle Czerkaszyn takes a behind-the-scenes look at how we captured the contents of the current displays for the Museum’s archive.
The archive here holds a unique collection of natural history books, journals and documents covering a wide range of subjects related to the Museum’s collections and research. It also contains papers and objects on the history of the building, providing an institutional memory of Oxford’s ‘University Museum’ since its foundation in 1860.
From an archive perspective it was really important to document the current layout of the cases, their specimens and text before they were removed from the court to make way for the new showcases in the first phase of our redisplay work.
The displays as we know them – with exhibitions on the Oxfordshire dinosaurs, Alice in Wonderland, the Oxford Dodo, and more – were last changed in 2000. For the last 20 years visitors to the Museum would remember their first time being wowed by the Megalosaurus jaw – the world’s first scientifically-described dinosaur – or charmed by the Dodo made famous in Lewis Carroll’s Alice Adventures in Wonderland.
Although after 20 years it is time for a change, the stories and information in the displays are too good to be forgotten. So before anything was removed we began to build the archive for the future.
The best way to capture all the information of the displays was through high resolution photography, but this was not as straightforward as we hoped.
The first two obstacles to good photographs are pretty obvious to anyone looking at the cases: glass causes huge amounts of glare; and each case has a big dividing line down the centre where the two sliding glass doors meet, cutting what should be a lovely seamless image into two halves.
To avoid glare and the solve the problem of the dividing line, our photographer Scott opened each individual side of the case, photographed two or three images of the display, and then stitched the separate photos together using Photoshop.
Another obstacle to taking good photographs of the displays came from the Museum itself. Some of our larger display furniture, such as the glass case for the Atlantic Bluefin Tuna or the huge T. rex plinth – got in the way of a nice straight shot. Because these items are so large and heavy they were impossible to move, so we had to improvise and do our best.
Thankfully, we managed to get shots of all 24 displays before they were removed and so a record of each case now rests with the Museum’s archive. If anyone wants to know what the display cases in the court looked like from 2000 to 2020, they will now be able to look back at the images in the archive and recall the magic of the Oxford Dodo exhibit that perhaps first made them fall in love with the Museum.
Our new displays are now in development, and will include some beautiful presentations of the diversity of life, looking at the importance and fragility of biodiversity and human impact on the environment. These new exhibits will show how the biological processes of evolution combine with the geological processes of our dynamic Earth to give rise to the immense, interconnected variety of the natural world.
We look forward to telling you more about that here as the project progresses.
Some of the very oldest complex, macroscopic communities on Earth appear in the fossil record about 570 million years ago and record the presence of a group of organisms – the rangeomorphs – with an unfamiliar body plan that, at their ultimate extinction, was lost from life’s repertoire.
Rangeomorphs are characterised by a strange frondose branching anatomy, where large primary branches host smaller branches which themselves host smaller branches again. This arrangement appears to maximise the surface-area to volume ratio of the organism, rather like a lung or a gill would today.
The smallest known rangeomorphs are less than a centimetre in length, but they grew huge and the largest records indicate they could stand more than two metres tall. There is no evidence to suggest that rangeomorphs were able to move around, rather, they lived stuck to the sea floor in the deep ocean, far below the reach of light.
Despite this strange set of characters, there is growing consensus that rangeomorphs likely represent very ancient records of animal life. However, they lived at such a remote time in Earth’s history that they do not possess any direct living descendants. Given all this, it may not be a surprise to hear that we know relatively little about how these organisms made their living and came to dominate the ancient seafloors.
In order to better understand them, my co-author Alex Liu and I travelled to Newfoundland, Canada to explore the rocks which host these remarkable fossils and over the past few years we have made an unexpected discovery. We found that fine filamentous threads connect rangeomorph fronds of the same species, in some cases over many meters, though they are typically between two and 40 centimetres long.
It is possible that these filaments were involved in clonal reproduction, like strawberry plants today, but they may have had additional functions such as sharing nutrients or providing stability in strong ocean currents.
The discovery of the filaments means that we have to reconsider how we define an individual rangeomorph, and may help us understand how rangeomorphs (seemingly) rapidly colonised deep-sea environments. Either way, some reassessment of the palaeobiology of these unique organisms is certainly required!
Our current First Animals exhibition is extending its run until 1 September, and to mark the extension our Research Fellow Imran Rahman takes a look at how animal life in the ancient oceans was brought to life in our Cambrian Diver interactive installation.
One of the biggest challenges in developing the First Animals exhibition lay in visualising rare fossil specimens as ‘living’ organisms, transforming them from two-dimensional imprints in the rock into three-dimensional animated computer models.
Many of the specimens on display in First Animals were collected from sites of exceptionally well-preserved fossils called Lagerstätten. These deposits preserve the remains of soft-bodied organisms that are almost never seen in the fossil record; things such as comb jellies and worms, as well as soft tissues such as eyes, gills and muscles. Even so, most of these fossils are flattened and two-dimensional, which makes it very difficult to reconstruct what they looked like in life.
To help exhibition visitors visualise the animals in a living environment we worked closely with Martin Lisec and his team at Mighty Fossils to create a set of detailed computer models of a key set of animals. We have worked with Martin before on the video of a Jurassic sea inhabited by plesiosaurs and other marine animals for our Out of the Deep display. That was very successful, but our idea for First Animals was even more ambitious: to create a unique interactive installation called the Cambrian Diver.
The material focused on the Chengjiang animals from the Cambrian of Yunnan province, China, which provides the most complete record of an early Cambrian marine community, from approximately 518 million years ago. Using fossil evidence of the organisms thought to have lived at the time we selected 12 species that were representative of the diversity of the Chengjiang biota.
The first phase was collecting as many materials as possible to be able to create 3D models. As usual, we started with rough models, where we set basic dimensions, shapes and proportions of body parts. Once approved, we moved to very detailed models for the animations, artworks and textures for less detailed models to be used within the interactive application. – Martin Lisec, Mighty Fossils
To provide two-dimensional templates for Mighty Fossils to work from we scoured the scientific literature for the most recent accurate reconstructions available for each of the species.
The predatory arthropod Amplectobelua symbrachiata is a good example. We drew heavily upon a 2017 paper by Dr Peiyun Cong and colleagues, which included a very detailed reconstruction of the head region. This reconstruction shows that the underside of the head of Amplectobelua consisted of a rod-shaped plate, a mouth made up of two rows of plates, and three pairs of flaps with spiny appendages, all details that are included in our 3D model.
Colour and texture were another consideration. To inform these we looked at living species that are thought to have similar modes of life today. For Amplectobelua, a free-swimming predator, we examined the colouration of modern marine predators such as sharks. Many sharks have countershading, with a darker upper side of the body and a lighter underside, which acts as camouflage, hiding them from potential prey.
We reconstructed our Amplectobelua model with similar countershading camouflage, with blue and red colouration inspired by the peacock mantis shrimp, a brightly coloured predatory arthropod that lives in the Indian and Pacific oceans.
The next vital step was establishing how the animals moved and interacted with one another. This is a major challenge because in many cases there are no modern equivalents for these extinct early animals. For Amplectobelua we inferred that the flaps on the sides of the body were used for swimming, with the tail fan helping to stabilize the animal as it moved through the water. This agrees with previous interpretations of swimming in closely related animals such as Anomalocaris.
The models were built and textured by Mighty Fossils using the 3D gaming engine Unity. The video below is an accelerated sequence showing how the elements of the model are layered together.
The finished, animated and annotated Amplectobelua model is shown below, and can be zoomed and rotated. All the models generated by Mighty Fossils for the First Animals exhibition are gathered in a collection on our Sketchfab page.
Once animated models of all 12 species were created we placed them in a realistic marine environment. Study of the rocks preserving the Chengjiang fossils suggests these animals lived in a relatively shallow, well-lit sea, perhaps 50 metres deep and characterised by a flat, muddy seafloor. A continuous shower of organic particles is thought to have filled the water column, as in modern oceans.
Based on present-day marine ecosystems, we infer that the number of immobile suspension feeders would have been much greater than the number of predators. As a result, we included multiple individuals of the suspension feeders Cotyledion, Saetaspongiaand Xianguangia, which were tightly grouped together, but only a small number of the active predators Amplectobelua and Onychodictyon.
The final step involved setting up a camera and user interface to allow visitors to discover the various animals in our interactive environment. For this we worked with creative digital consultancy Fish in a Bottle to identify eight locations, each focused on a different animal.
As the video above shows, users can navigate between locations by touching an icon on the screen, and when the Cambrian Diver sub arrives at a location information about the animal, its mode of life and its closest living relatives is presented on-screen. A physical joystick allows users a 360-degree rotation to look around the scene, and explore the ancient watery world.
This project was significantly bigger than the Out of the Deep work we had done previously with the Museum, mainly because of the complicated approval procedure needed for 20 individual 3D models. Along with three large illustrations, two animations and the interactive application this was a big workload! Fortunately, we managed to finish the whole project on time for the opening of the exhibition. – Martin Lisec
From cockroaches hissing alluringly to their mate, to smooth newts wafting intoxicating pheromones, and butterflies with eyes in their genitalia, the amorous pursuits of the natural world are enough to make St Valentine blush.
Valentine’s Day may conjure images of Cupid and his arrows, and indeed the romantic cherub of mythology has a brutal counterpart in nature. When the hermaphrodite Garden Snail (Helix aspersa) snuggles up to mate, both partners try to stab each other with love-darts in a mating duel. These darts are coated in chemicals that increase the chances of the dart-receiver’s eggs being fertilised. Love is a dangerous game: sometimes a dart misfires and hits a vital organ – a dart to the heart.
Traditionally given as wedding presents in Japan, the lacy white deep-ocean glass sponge Euplectella, known as Venus’ flower basket, offers an interesting take on “…’til death do us part”. When a young shrimp pair enters the sponge to mate, they become trapped inside as they grow too large to escape. The couple then spend the rest of their lives together, caged in the sponge, whilst their offspring are small enough to leave through the small gaps and seek sponge-mates of their own.
And if you forgot all about Valentine’s Day you will no doubt be panic-buying a bunch of overpriced roses on the way home, but be heartened that humans are not the only creatures that try to attract mates by presenting each other with gifts. The male Bowerbird builds a bower to attract females, decorating it with brightly coloured embellishments including flowers, leaves, stones, and even bits of plastic.
Meanwhile, male Empids (dance flies) offer a high-protein ‘nuptial gift’ – a gloopy sac called a spermatophore – for the female to eat during copulation. One theory is that females use the size of the gift as a way of choosing their mates…
Moving on from the natural world to natural historians, in 1835, Frederick William Hope married the wealthy heiress Ellen Meredith. He donated one of the founding collections to the Museum that they subsequently worked on together, the inspiration behind our current HOPE for the Future project. Meredith had recently rejected a marriage proposal from the future Prime Minister Benjamin Disraeli, stating that:
a life as the wife of a politician would have been a very dull one indeed
We at the Museum completely understand that weekends rootling around in dung for beetles with her entomologist husband seemed more appealing than stiff diplomatic receptions at Number 10.
Fast forward to the modern day, and romance is in the air at the Museum, as many couples celebrate their marriages here each year. Every wedding has a different flavour, depending on the interests of the bride and groom, but natural history puns are guaranteed during the speeches, and dancing amongst the dinosaurs is a must!
It may seem like a strange idea to tie the knot in a Museum, but perhaps 60-odd years of marriage seems comfortingly short in the context of 4.5 billion years of geological time?
If you are interested in talking with our events team about celebrating your wedding at the Museum of Natural History, contact Laura and Megan at email@example.com / 01865 282780.
Top image: Gold-fronted Bowerbird, once thought to be extinct, but rediscovered in the Foja Mountains of Indonesia, painted by activist artist Jane Mutiny for the Conservation Optimism film festival at the Museum in 2019.
As we embark on our Life, As We Know It redisplay project – the first substantial changes to the permanent exhibits in more than 20 years – our Senior Archives and Library Assistant Danielle Czerkaszyn takes a look back at 160 years of an ever-evolving museum, in the first of a series of posts around the redisplay.
On 15 June 1860, Henry W. Acland, Regius Professor of Medicine at the University of Oxford, wrote:
The Oxford Museum slowly approaches completion. The building will shortly sink into insignificance when compared to the contents it will display, and the minds it will mould.
The University Museum at Oxford, as the Museum was originally known, was established to bring together scientific teaching and collections from across the University under one roof. The doors opened in June 1860, and soon after several departments moved into the building – Geometry, Experimental Physics, Mineralogy, Geology, Zoology, Chemistry, Astronomy, Human Anatomy, Physiology, and Medicine.
When the University Museum opened, it was not simply a museum; each department got a lecture room, offices, work rooms and laboratories, as well as use of the library and display areas. According to Acland, a key figure in the Museum’s foundation, in 1860 the outer south aisle of the main court featured mineralogical specimens and chemical substances, while the inner aisle exhibited Oxfordshire dinosaurs.
Acland’s detailed descriptions of the central aisle highlighted zoological specimens with twelve parallel cases of taxidermy birds, four side cases of taxidermy animals, including animals on top of the cases, and six table cases down the centre showing shells, crabs, insects, corals and sponges, starfish and urchins. The inner north aisle presented reptiles and fish, while the outer aisle introduced the Ashmolean‘s zoology specimens, as well as anatomical and physiological collections.
Although members of the public were welcome in the Museum from the start, the departments which inhabited the building were more concerned with teaching space, research facilities and the storage of their specimens than the needs of visitors. As a result, most of the early displays and cases were arranged in a systematic manner that focused on space-saving practicalities and communicating scientific knowledge, rather than aesthetics.
Tracing through old annual reports it is clear that cases in the main court have been almost constantly refreshed and updated, with displays highlighting new specimens and changes to scientific understanding, or through practical improvements to lighting, electricity points and environmental monitoring. Nonetheless, the overall layout of the cases remained the same until the early 1980s.
From the early 1990s a focus on public engagement began to increase. Longer opening hours were introduced and displays were redesigned to link to both undergraduate teaching as well as the National Curriculum. Temporary exhibitions also regularly featured in the main court to increase the variety of specimens on display.
The turn of the millennium marked the start of a major project to update the main court displays. The central cases were reconfigured and a new set of introductory cases installed, including many themes familiar to visitors in recent years, such as exhibits on the Oxfordshire dinosaurs, Alice in Wonderland, and the Oxford Dodo.
These showcases were complemented by the addition of an imposing cast of ‘Stan’ the Tyrannosaurus rex in the centre aisle, positioned behind the historic Iguanodon cast. The changes were well received and attendance in the month of July 2000 was the highest ever recorded. The Museum also introduced live insects for the first time in 2000, with Upper Gallery tanks containing Madagascan Hissing Cockroaches, South American Burrowing Cockroaches, a variety of stick insects, and some large tarantulas.
The project completed in late 2005 when the displays on Evolution, the History of Life, and Invertebrate Biodiversity were installed. Touchable specimens were also given their own permanent display area, allowing visitors the opportunity to physically interact with natural history material. These and other public engagement activities were recognised when the Museum won The Guardian newspaper’s Family Friendly Museum of the Year Award for 2005.
The last substantial update to the fabric of the building took place in 2013, when the Museum closed for a year to fix the leaks in the glass roof. Taking advantage of the closure, a major piece of conservation work was undertaken on the seven whale specimens suspended from the roof. Having been on display for over 100 years, the whales were in need of considerable TLC.
Today, new and exciting changes are afoot as we embark on the first major changes to our permanent displays in almost 20 years. New high-end showcases will present displays under the concept of Life, As We Know It– beautiful presentations of the diversity of life, and the importance and fragility of biodiversity and human impact on the environment. The new exhibits will look at how the biological processes of evolution combine with the geological processes of our dynamic Earth to give rise to the immense, interconnected variety of the natural world.
Looking back across the decades we can see that the Museum is never static, but instead constantly changing and adapting, shifting from its foundation as a Victorian centre of academia to the accessible and engaging space we know and love today.