Amgueddfa Blog: Natural History

Written by Caitlin Jenkins, MSc Conservation Practice student, Cardiff University

I’m Caitlin, an MSc Conservation Practice student from Cardiff University and I have just finished my summer placement at National Museum Cardiff. I’ve been working with conservator Julian Carter on the natural history collections, with the last five weeks focused on preparations for the museum’s summer exhibition, Snakes!

The first week saw me elbow deep in jars full of snakes, as we worked our way through getting 32 fluid preserved specimens ready for display. Although the snakes had already undergone previous treatment, many were very old and in need of attention. After checking the jars’ condition, we added or replaced conservation fluid as required.

Replacing the preserving fluid in the jars

Many snakes needed to be rehomed in new jars. Some preservationists use wires or mountings, but we chose to follow the natural shape of the snake and its flexibility to guide its positioning within the jar. My favourite of the specimens was a grass snake that had been preserved in the act of eating a toad (with one leg dangling from its mouth...poor toad!)

Topping up the preserving fluid for a grass snake

I was also able to assist with preserving a new addition to this collection – a boa constrictor named Aeron. After formaldehyde injections and several fluid changes, we needed to find an extra-large shiny new jar, because he was over a metre long. Aeron has now bagged a starring role as the centrepiece of his display case. I really enjoyed this experience, and it has given me a fantastic insight into the complexities and potential of fluid preservation.

Injecting the Boa with preserving fluid

Rhodri Viney from our Digital media team filmed the whole process of preserving the Boa

Aeron the Boa looking magnificent in the gallery

My other major project was the treatment of three snake models destined to be part of a large interactive exhibit within Snakes! Two were painted plaster models of a rattle snake and a king cobra. These incredibly detailed antiques were perhaps cast from real specimens. The third was a moulded rubber and polystyrene grass snake model from the 1960s. The models had survived in remarkably good condition given their age, they just needed a little ‘zhoosh’ to make them display-ready. Light brushing and swabbing with water and mild detergent was all that was needed to remove ingrained dust. Any loose or flaking areas were consolidated to ensure that they didn’t become further detached from the model.

Cleaning the rattlesnake model

Nevertheless, small elements were missing from each model. The grass snake model posed a specific conservation risk, as rubber and plastics can become unstable over time. Its tongue became fragmented during cleaning and unfortunately proved too badly degraded to reattach. Using photographs of the real-life snake species as a guide, I fashioned replacement tongues for this and the king cobra model from a strong plant-based fibre known as Japanese tissue. They were secured in place and painted to blend them into the jaw area. Being able to see the immediate improvement after each snake ‘facelift’ was very satisfying - this took cosmetic surgery to a whole new level!

Finally, the finished models were settled into their new home for the summer – a large interactive exhibit affectionately dubbed ‘the snake pit’. I’d become so immersed in their treatment over the last five weeks that I was kind of sad to see them go – but it was satisfying to see them looking their best and used in the spirit for which they were originally created.

The finished snakes in their jars ready to go up to the gallery

I’ve really enjoyed working on Snakes! from preparation to completed display – it’s been a fantastic experience. If you are in the vicinity of the museum, pleasssse pay them a visit.

The exhibition runs till 15th September 2019, entry charges do apply, and all your contributions go towards bringing you even bigger and better exhibitions in the future. Please note that there is no live handling of the snakes within the exhibition, there will be a series of bookable handling sessions throughout the summer as well as a Venom themed Open Day in August. To find out more about all of this, go to our What's On page.

On the 22nd June our new summer exhibition opened. This family friendly exhibition runs until September and delves into the captivating life of snakes, helping you to find out more about these extraordinary and misunderstood creatures. We are hoping to feature more detailed stories about all of the things mentioned below in a series of blogs running through July and August so keep tuning in to find out more.

Dr Rhys Jones at our opening launch event.

Snakes is a touring exhibition created by a company called Blue Tokay with added bonus content generated by our team. Work began on bringing together all of this way back in September 2018 and since then we have been busy researching, writing text and preparing some great specimens for you all to enjoy.

The main exhibition covers all aspects of the lives of snakes, so we focused our efforts on highlighting our collections at the museum. We hold over 3.5 million natural history specimens here, and as you can imagine, not everything is on display. We hold a small collection of 500 reptiles from all over the world. These are mostly preserved in alcohol and stored in jars, but we also have skeletons, skins and eggs. We chose 32 of our best snakes to go out on display. Each of these were carefully rehoused and conserved as many of the specimens were old and in need of work.

Some of the fantastic snake collections at the museum.

Our Conservation intern, Caitlin Jenkins, hard at work rehousing the snakes.

But it’s not just snakes in jars. We have also displayed some fantastic casts of 49 million years old fossil snakes, and 3D printed the vertebra of Titanoboa, the largest snake that ever lived.

Snake evolution case featuring casts of snake fossils.

One of my favourite features of the exhibit are our objects dealing with snake folklore and mythology, featuring a 13th century manuscript showing how snakes were used in medicinal remedies. Also some fantastic ‘snakestones’, actually fossil ammonites with snake heads carved on to the top.

Getting out the Snakestones from the collections.

You may also recognise the statue of Perseus that has long been displayed in our main hall. Perseus is enjoying his new surroundings, with Medusa’s snake ridden head looking positively sinister with the new lighting.

Perseus with the severed head of the serpent haired Medusa.

The exhibition features six live snakes and as I’m sure you can imagine, bringing live animals into a museum requires a LOT of preparation. We have done a great deal of work to ensure that their time with us is spent in 5 star accommodation. Their ‘vivaria’ are purpose built to ensure our snakes are well cared for, including warm and cool spots, as well as a water feature for a bathe. We have a fantastic (and very brave) set of staff who are volunteering their time to looking after them including changing water bowls, and clearing up their poo! Dr Rhys Jones (Cardiff University) has been fantastic with helping throughout this whole process, including coming in every week to feed them. The snakes are all provided by a company called Bugs n Stuff, you can see a video of them installing the live snakes here.

The largest of our live snakes, Prestwick, the Jungle Carpet Python.

Dr Rhys Jones with some of our staff at the live snake care team meeting.

Guy Tansley from Bugs N Stuff with Mela, the Boa constrictor.

Finally, our fantastic learning department, design team and technicians have worked hard to add some fun activities for all to enjoy. Our Spot the Snake pit features, amongst other things, two beautifully conserved models of a cobra and a rattlesnake that date back to 1903, and a real freeze-dried adder! We also have a snake expert quiz, a world map of snakes, and drawing and colouring stations. Volunteers will be in the gallery periodically across the summer with snake handling specimens including a real full length skin of an African Rock Python.

The exhibition runs till 15th September 2019, entry charges do apply, and all your contributions go towards bringing you even bigger and better exhibitions in the future. Please note that there is no live handling of the snakes within the exhibition, there will be a series of bookable handling sessions throughout the summer as well as a Venom themed Open Day in August. To find out more about all of this, go to our What's On page.

 

Into June and we have selected silicon as our element of the month. This element might not be instantly recognisable as of significance to Wales, but it does have an interesting history.

Silicon (chemical symbol – Si), atomic number 14, is a hard but brittle crystalline solid, with a blue-grey metallic lustre. Silicon is the second most abundant element (about 28% by mass) in the Earth’s crust after oxygen with which it has a strong affinity. Consequently, it took until 1823 for a scientist - Jöns Jakob Berzelius – to prepare it in pure form.

In Wales, silicon is present virtually everywhere in one form or another: from quartz (silicon dioxide, SiO2) in sedimentary siltstones, sandstones and conglomerates; complex silicates in igneous and metamorphic rocks; to sediments in soils.

Silica (silicon dioxide, or quartz) was mined extensively in the Pontneddfechan area, in South Wales, from the late 18th century until 1964 for the manufacturing of firebricks for kilns and furnaces. It occurs as a very pure material highly concentrated in quartzite within a geological unit known as the Basal Grit. Weathering and erosion of the quartzite has produced deposits of silica sand and this was extensively quarried for the production of refractory fire bricks for the smelting industries.

In North Wales, a little-known trade in rock crystal – a colourless, glassy variety of quartz crystal – took place in Snowdonia during the 18th and 19th centuries centred upon the village of Beddgelert. T. H. Parry-Williams refers to this in one of his writings. Miners and mountain guides searched for veins of quartz in the mountains and collected crystals to sell to tourists as curios and some were possibly used to make crystal chandeliers. Later, crystals were occasionally discovered in the vast slate quarries, or during the large-scale construction of forestry tracks during the 1960s.

Silicon, as silica (another name for silicon dioxide) is also important to certain organisms. In particular diatoms and sponges.

Diatoms are single-celled microscopic algae with a complex cell wall made of silica. They are abundant in all waters, produce oxygen and are food for other aquatic organisms. Diatoms are also frequently used to monitor water quality.

Sponges build their skeletons from a framework of tiny elements called spicules, which are made of silica in most sponge groups.  One of the most beautiful examples is the Venus’ Flower Basket glass sponge, which lives anchored to the deep ocean floor near the Philippines.  A pair of shrimps lives inside this sponge, breeding inside it and spending their whole lives protected within its delicate glass walls.  Thanks to this unusual symbiotic relationship, the dead skeletons of Venus’ Flower Baskets are a popular wedding gift in Japan.

Sponges are the most primitive kind of animal on Earth, and their resistant spicules are found as fossils from as far back as 580 million years ago. Silica is also important in the preservation of other types of fossil.  When dead animals or plants are buried, silica from groundwater can fill in the pores and other empty spaces in wood, bone or shells, and/or it can replace the original remains as they decay or dissolve.  This is most common in areas where the groundwater has high silica levels, due to volcanic activity or erosion of silica-rich rocks.  The organic remains act as a focal point for silica formation, and often the rock surrounding the fossils is made of different minerals.  For example, shells that were originally made of calcium carbonate can dissolve and be replaced by silica, whilst being fossilised within limestone (calcium carbonate).  Extracting the fossils is a simple process of putting the rock in some acid and waiting for it to dissolve, leaving behind the silicified fossils.  The Museum’s fossil collections include many silicified shells of brachiopods, ammonites, bryozoans and other sea creatures.

One of the most spectacular types of fossil preserved in silica is ‘petrified wood’.  Silica replaced the original cells of the wood as it decayed and also filled in any gaps, literally ‘turning it to stone’.  In some places, including Patagonia and the USA, whole tree trunks replaced by silica are found in so called ‘petrified forests’.  Other plant fossils, such as cones, can also be fossilised in this way.

Chert is a rock made of very small crystals of silica.  Many major chert deposits formed at the bottom of ancient oceans from ‘siliceous ooze’, which is made of the skeletal remains of millions of tiny organisms including diatoms and radiolarians (single-celled plankton).  Chert nodules can also form within other rocks through chemical processes. 

Chert found within chalk is known as flint, and was a very important material for making tools throughout Prehistory. Tools are made by knapping, that is striking a prepared flint edge, or striking platform, with a harder stone to detach pieces called flakes or blades. These flakes, blades, and indeed the core from which they are struck can then be modified with secondary working into fine tool forms. Amongst the most skilful are fine arrowheads, including these from a Bronze Age grave at Breach Farm, Vale of Glamorgan, Wales. Flint was generally the material of choice for making sharp cutting tools as it is so fine-grained and fractures conchoidally and cleanly it gives a really sharp cutting edge. Indeed, so much so, that anecdotally eye-surgeons are reported to occasionally use a freshly struck flint blade in the operating theatre!

Because it is very fine-grained and hard, chert can preserve fossils of very small things from far back in our planet’s history.  The oldest potential fossils on Earth are found in cherts, and include the possible remains of bacteria from over 3 billion years ago.  Younger fossils, from the Rhynie Chert of northern Scotland, provide a glimpse of one of the earliest land communities, 400 million years ago.  Simple plants, and animals including primitive spider-like creatures and scorpions, were preserved in fine detail thanks to silica-rich water from volcanic hot springs.

Opal is a hydrated form of silica, meaning that it contains between 3 and 21% water.  Unlike standard silica, it does not have a set crystal form, but some of its forms diffract light, creating a beautiful iridescent effect in a variety of different colours.  For this reason, opal has been prized for centuries as a gemstone for making pendants, rings and other jewellery.  Australia produces a lot of the world’s opal, and is also a source of rare and spectacular opalised fossils.  The shells of invertebrates such as belemnites (prehistoric squid-like creatures), and even dinosaur bones, have been replaced by opal, creating very colourful specimens in a world where fossils are usually grey or brown.

Within Amgueddfa Cymru’s botany collections are books of dried plant specimens created by scientists and enthusiasts. Each specimen has been carefully dried and pressed, before being added to the books, sometimes with handwritten or printed notes alongside. The books are of enormous importance both in terms of modern scientific research into climate change and biodiversity, and as a way to see first hand the history of botanical exploration.

You can now look through a catalogue of the 36 books that contain non-flowering plants, fungi, lichens and seaweeds. You can read about a few of the stories surrounding these books below. For more detailed information about each book, please visit the website.

These books show the changes in how we collect, classify and name plants over two centuries from 1800 to present day. An old volume which probably dates from the 19th century entitled “New Zealand Mosses”, contains more than just mosses. Lichens, algae and even some pressed hydrozoans (tiny marine animals) have been included by the unknown collector who chose to group these superficially similar ‘moss-like’ specimens together. This donation entered the Museum’s collections after its Royal Charter was received and before work had begun on the present Cathays Park building.

While the earliest currently known non-flowering plant specimen in the Museum is a moss collected in 1794 from Gwynedd, the earliest specimen book dates from 1803. This book is Lewis Weston Dillwyn’s personal collection of seaweed and freshwater algae collected between 1803 and 1809. Dillwyn’s specimen book was donated to the Museum in 1938 by the National Library of Wales, and has great importance both scientifically and historically.

Lewis Weston was part of the influential Dillwyn family, and his son John Dillwyn Llewelyn became an early pioneer photographer. He was interested in the natural history that he saw in south Wales where he lived. This is reflected in his scientific research as well as in the pottery designs created while he was owner of Cambrian Pottery. Dillwyn described new species of algae and his specimen book contains type specimens (irreplaceable specimens used in the original description of a species). The book is a personal record of his scientific life, recording places he visited and scientists who sent him specimens. He became a Fellow of the Royal Society in 1804 and later had a plant genus named after him in recognition of his work.

Many of the botanical specimen books in National Museum Cardiff have a fascinating history. Two contain mosses collected by Thomas Drummond on the Second Overland Arctic expedition between 1825 and 1827 to British North America (now Canada). Delving further into the book’s background reveals that the Captain, Sir John Franklin, sent Drummond to the Rocky Mountains with one Native American hunter. After the hunter left him on his own, he survived a severe winter, being mauled by a bear, and starvation. He still managed to collect, preserve and study many new plants of the North American continent. This work was published by Sir W.J. Hooker, who later became the director of the Royal Botanic Gardens, Kew.

The more recent books are systematically collected specimens known as ‘exsiccatae’. These are sets of duplicate specimens distributed by scientists to other museums. They help to spread the risk of losing a particularly important set of specimens, and to allow scientists around the world to study them. Lists of their contents are usually published in a journal or online. Much of the Berlin Herbarium and the botanical specimens within it was destroyed in World War 2, however many duplicate specimens from this collection survive in other herbaria around the world. From around the 1900s, exsiccatae changed from being bound books to being loose specimens. This meant museums receiving them could incorporate them into their collections alongside other closely related specimens for easier access and comparison.

 

Continuing the international year of the periodic table of chemical elements, for April we have selected Calcium. Known by most as the fundamental element in bone-forming or limestone, it has a host of other applications and is present in seabeds and marine life past and present.

Calcium (Ca) is a light-coloured metallic element with an atomic number of 20.  It is crucial for life today and commonly forms a supporting role in plants and animals. The 5th most common element in the earth’s crust, calcium forms many useful rocks and minerals such as limestone, aragonite, gypsum, dolomite, marble and chalk.

Aragonite and Calcite, the two most commonly crystalised forms of calcium carbonate, helped form the 2 million shells in our mollusc collection, the core of which is the Melvill-Tomlin collection, donated to the museum in the 1950s. An international collection it contains many rare, beautiful and scientifically important specimens and is utilised by worldwide scientists for their research. Pearls, also made of aragonite and calcite, are produced by bivalves such as oysters, freshwater mussels and even giant clams. In nature pearls are the result of the molluscs’ reaction against a parasitic intruder or a piece of grit. The mantle around the soft bodied animal secretes calcium carbonate and conchiolin that surrounds the invading body and imitates its shape so they are not all perfectly spherical. In the pearl industry the oyster or mussel is ‘seeded’ with a tiny orbs of shell to ensure that the resulted pearl is totally spherical.

Mollusc shells are created as protective shields by their soft-bodied owners and this is true of other invertebrates, especially in the world’s oceans. Coral reefs and some marine bristle worm tubes (Serpulidae, Spirorbinae) rely on the reinforcing nature of calcium carbonate to provide support and protection to their soft bodies. Crustaceans such as crabs and lobsters have a hard exoskeleton strengthened with both calcium carbonate and calcium phosphate. Calcium required after moulting in lobsters, crawfish, crayfish and some land crabs is provided by gastroliths (sometimes referred to as gizzard stones, stomach stones or crab’s eyes). They are found on either side of the stomach and provide calcium for essential parts of the cuticle such as mouthparts and legs. The museum’s collections holds nearly 750,000 marine invertebrates, including crustaceans, corals and bristleworms.

Many of the 700,000 fossils in the Museum’s collections are also made of calcium minerals.  Invertebrates use two main forms of calcium carbonate to make their shells and exoskeletons, and the one they use influences how likely they are to be immortalised as fossils.  Aragonite, found in the shells of molluscs such as ammonites, gastropods and bivalves, is unstable and doesn’t usually survive for millions of years.  During fossilisation, aragonite shells either dissolve away completely, or the aragonite recrystallizes to form calcite.  Calcite was used to make the shells and skeletons of extinct groups of corals, articulate brachiopods, bryozoans, echinoderms and most trilobites.  It is much more stable than aragonite, so the original hard parts of these creatures are commonly found as fossils, millions of years after they sank to the sea floor.  Large calcite crystals are often found filling spaces in fossils, such as the chambers inside ammonite shells.  Vertebrates use a different calcium mineral to make their bones and teeth: apatite (calcium phosphate), which can survive for millions of years to make iconic fossils such as dinosaur skeletons and mammoth tusks.

The Museum’s rock collections contain many limestones, rocks formed at the bottom of ancient seas from bits of shells and other calcium carbonate-rich remains.  For millenia, people have used limestones as a construction material: from carved stone in the iconic Greek and Roman temples; broken fragments as ballast in the base layer of railways and roads; or burnt to form lime in the manufacturing of cement.  National Museum Cardiff and other iconic buildings in Cardiff Civic Centre were built from a famous Dorset limestone called Portland Stone.  The Museum’s floor is tiled with marble, limestone that has been transformed (‘metamorphosed’) under great heat and pressure.  Marble has long been prized by sculptors, since the ancient Greeks and Romans. The Museum’s art collections include works in this material by Auguste Rodin, John Gibson, Sir Francis Chantrey, Sir William Goscombe John, and many others. There are also important examples of work by twentieth-century sculptors, such as Jacob Epstein, Eric Gill and Henri Gaudier-Breszka. They preferred carving the softer texture and density of the softer limestone, Portland Stone and sandstone.