: Geology

This blog is about fossils whose beautiful patterns have intrigued us for as long as we’ve been human. These animals survived the evolutionary power struggles of the past to leave their relatives in today’s oceans. They are the Sea Urchins, or to give them their scientific name, the Family Echinoidea - Echinoids to their friends.

A ‘Hedgehog’ by name, but not by nature

Their name comes from the Greek ‘Echinus’, meaning Hedgehog, because of their spines. People in the Middle Ages had the idea that each kind of land animal had a matching version living in the sea; sea-horses, sea-cows, and so on. So the spiky Echinoid was naturally called a Sea-Hedgehog. This might sound daft today, but we still call the Echinoids’ cousins “Starfish” though we know they’re nothing to do with fish at all !

Like little armoured aliens

The bodies of echinoids are really strange, almost like something from science-fiction. Being covered in massive spiny stilts you can walk on is weird enough, but inside their box of a shell they’re even more peculiar. They have a multi-purpose organ called the water vascular system. It’s a central bag of fluid connected to five lobes which lead to many tiny tubes coming out through pores in the shell. These are its tube-feet. It can move them around by changing the pressure inside the bag. They’re very handy for dragging itself along the sea floor, sensing the surroundings, and for getting food to its mouth. Some burrowing echinoids can even stick a tube foot up above the sand to get oxygen from the water.

Their basic body plan has proved to be very well adapted to a life of sea-bed scavenging. They move along like armoured tanks eating up whatever they can find; mostly algae, but their set of five toothed jaws can deal with a varied diet.

Cherished by the Ancients

The beautiful shells of echinoids have fascinated humans for a very long time indeed, maybe because they’re so different from other animals on the planet. Most animals have just one line of symmetry and an even number of limbs. But echinoids and their cousins the starfish can show star-like five-fold symmetry.

We know that this struck many people in the past. Ken McNamara gives the following two examples in his book “The star-crossed Stone” about the rich folklore of echinoids.

The oldest example of a collected and labelled fossil, is an echinoid with Egyptian hieroglyphics inscribed on it about 4000 years ago. It was found “in the south of the quarry of Sopdu, by the god’s father Tja-Nefer”. Sopdu was called the god of the morning star - he was a kind of border-guard god, and it’s been suggested that echinoids were important to the Egyptians in some way in their travels to the afterlife.

But human fascination with echinoids stretches back much, much further than that; long enough for the great ice sheets to have advanced and retreated across Britain four times since. About four hundred thousand years ago in what is now Kent, someone chose to make a tool from a flint containing a fossil echinoid. Most flint tools have two cutting edges, but this one may have been left unfinished on purpose. If the maker had chipped the flint to make the other edge, the fossil would have been destroyed. What is amazing is that this person was not a Homo sapiens like you or I, but either a Homo heidelbergensis or a very early Neanderthal (Homo neanderthalensis). Other humans were collecting fossils before members of our own species left Africa.

Trevor Bailey, Senior Curator – Palaeontology. This blog was adapted from a gallery tour I gave at the National Museum Cardiff.

Turkey may seem a long way away to the people of Wales. But events there some 300 million year ago have had a profound and lasting effect, on our Welsh climate, landscape and wildlife.

For about 10 million years, Wales was part of an enormous tropical swampland extending from eastern North America to Turkey and the Caucasus. The dead remains of the plants that grew there caused massive deposits of peat to build-up. This peat was then buried by mud and sand, and the resulting heat and pressure changed it into the coals on which much of the industrial growth of places such as Wales depended, especially in the 19^th and early 20^th centuries.

But nothing lasts for ever, and the swamps eventually dried up and the accumulation of the economically important coal-forming peat came to an end. What caused this profound change to the environment has been the subject of much scientific debate. Research co-ordinated from Amgueddfa Cymru–National Museum Wales (as part of the International Geoscience Programme project IGCP 575) suggests that it was due to the combination of two major factors.

1. Landscape Change: The collision of two large continental plates (Euramerica and Gondwana) caused a massive upheaval of the landscape, with rivers changing direction and new mountain ranges forming. The effect of these changes was particularly felt in the areas where the swamps had been.
2. Climate Change: The changing landscape caused a different type of vegetation to grow here, and this coincided with a significant warming of the climate and a reduction in rainfall.

Importantly, these environmental changes started first at the eastern end of these swamplands, in places such as northern Turkey, and then progressively moved westwards towards Wales.

So, in order to understand properly what caused the collapse of this ancient wetland in Wales, we need to study events in Turkey. To do this might have needed extensive (and expensive) field excursions to the area. Fortunately, we have a scientific resource nearer to hand that can provide at least a start to this work. In the years just before and after World War II, the great Dutch palaeobotanist Wilhelmius Jongmans led expeditions to northern Turkey to collect Carboniferous plant fossils. He sadly died before he could properly work on them. Fortunately, however, his collection of over 5,000 Turkish fossils is now stored safely in the Naturalis Museum in the Netherlands.

Chris Cleal from Amgueddfa Cymru–National Museum Wales is now leading a collaborative project with colleagues from the Netherlands, Germany and the UK, to research this collection – using expertise developed in Wales to bear on an internationally important problem. It will help us understand what controlled the formation of coal deposits such as those found in Wales, and how vegetation, atmosphere and climate interacted in Carboniferous times. 

The world 300 million years ago was in many ways similar to today (far more similar to what it was in the intervening millions of years ago, for instance in Mesozoic times, when the dinosaurs were roaming around). Studying how climate, vegetation and the atmosphere interacted in this ancient world therefore allows us to check some of the assumptions on which scientists have been basing their modern-day climate models.

This shows the importance of international collaboration between museums in scientific research – why it is vital for scientists in Wales to work with colleagues from across the world.

We have had more of our I Spy Nature Competition winners in for special behind the scenes tours of National Museum Cardiff.

We ran a drawing competition as part of our I Spy Nature Pop-up Museum at the Capitol Shopping Centre over the summer. We had some fantastic entries and it was extremely difficult to choose the winners. However, we managed to select several winners and they were given natural history related goodies from the Museum’s shop and offered special tours to see what happens once you leave the public galleries and go into the museum’s collections.

These three lucky winners had tours in the fossil and mineral collections with palaeontologist Dr Lucy McCobb and mineral curator Andrew Haycock. 

Some of our other winners have also been in to see what happens in the marine, shell and vertebrate collections.

On Saturday 10^th October, scientists from the Museum’s Natural Sciences Department and Cardiff University came together to mark both National Biology Week and Earth Science Week, and to prove that biology (and geology) does indeed rock!  Engaging displays and fun activities filled the Main Hall and were also scattered through the lower natural history galleries and Clore Learning Space.  Visitors collected a stamping sheet at the door and could claim a stamp for every activity they completed.  Everyone who collected ten stamps had the chance to colour in and make their own natural history badge to take home.  Museum scientists wowed visitors with specimens from our collections behind the scenes, including the largest seeds in the world, glow-in-the-dark minerals and huge scarab beetles.  Visitors could also explore sea creatures and seaweeds in a rock pool, and have a go at matching fossils to their correct place on a timeline of the Earth’s history.  Fans of the game ‘Operation’ had the opportunity to try their hand with an actual size, adult dummy version, courtesy of biologists from Cardiff University, who also presented a range of other fascinating topics, including what we can learn from road kill, how healthy babies are made, how toadstools get their white spots and how to extract DNA from strawberries.  Appropriately enough, the University’s team of geologists set up shop at the entrance to the Evolution of Wales gallery, and invited visitors to experiment with what makes an explosive volcano, try to bend rocks and have a go at stepping in the footsteps of dinosaurs.  The day also featured several family-friendly events linked to the ‘Reading the Rocks: the remarkable maps of William Smith’ exhibition.  Theatr na nÓg gave three performances of a one-man play exploring Smith’s work from the point of view of his young Welsh apprentice, and scientific historian Dr Leucha Veneer gave a family talk looking at early ideas about rocks and fossils.

We were joined this Saturday by three of our I Spy…Nature drawing competition winners and their families. The winners were shown around the shell, marine invertebrate and vertebrate collections as part of their special behind the scenes tour by museum curator Katie Mortimer-Jones. The tour started in the fluid store, where we keep our fluid preserved specimens such as marine bristleworms, starfish, crabs, lobsters and fish specimens. The competition winners saw some of our oldest fluid preserved specimens in the collections – Octopus, squid and cuttlefish specimens worked on by the very first director of the museum, William Evans Hoyle. Next on to the shell collections, one of the largest collections at the museum. Our visitors looked through draws of molluscs, spying Giant Clams, abalone shells and Giant African Land snails. Lastly the tour finished up in the Vertebrate store where we keep some of the Museum’s taxidermy and skeleton specimens. On display were several fox specimens, a crocodile, sheep and fish specimens that will be on display in a house next weekend as part of the ‘Made in Roath Festival’. After the tour, the winners were given their prizes of natural history goodies from the Museum Shop.