Like me, many of you will have been glued to Sunday evening television for the last few weeks, watching the BBC’s astonishing Blue Planet II. From octopus battling sharks to fish using tools to find food, the series has provided new and stunningly beautiful portrayals of the mystery and wonders of the oceans.
Sitting in Birmingham on a cold, dark, winter’s day, the ocean seems a long way away. Indeed, Birmingham lies about as far from the sea as you can get in the UK. A recent tongue-in-cheek ranking of UK universities based on height above sea level placed Birmingham third (140 metres), and thus among the least likely to be inundated by future sea level rises. But it hasn’t always been this way.
The Lapworth Museum of Geology at the University of Birmingham holds a rich and internationally recognised collection of fossils from the West Midlands and beyond. These fossils tell the story of more than 500 million years of evolution and local environmental change, as sea level has risen and fallen, temperatures have changed from tropical to glacial, and the Earth’s tectonic plates have inched their way slowly across the globe.
Some of the most important fossils in the collection come from Dudley, in the Black Country to the west of Birmingham. Limestones in and around Dudley were mined for use in the production of iron during the industrial revolution of the late 18th and 19th centuries. The local miners regularly found fossils, and sold them to fossil shops and wealthy fossil collectors. Many of these fossils eventually made their way to the Lapworth, as well as to other museum collections worldwide.
These remarkably preserved and beautiful fossils are of marine animals like corals, snails, sea lilies, and starfish. They provide proof that the Midlands was once covered by a shallow, tropical sea. We now know that the limestones containing these fossils formed about 428 million years ago, in the Silurian period, when sea level was much higher than today, and the Midlands lay to the south of the equator. More like the Bahamas than modern-day Dudley.
Perhaps the best-known of these Silurian fossils is the ‘Dudley Bug’ - one of the group of extinct marine animals are called trilobites, which look superficially like large woodlice. The Lapworth Museum holds the original specimen of this fossil species, which is famous enough locally that it formerly appeared on the Dudley County Council coat-of-arms. Today, the geological heritage of the Black Country is of such importance that UNESCO is currently considering an application to recognise the area as a Global Geopark.
The Silurian wasn’t the only time during which the Birmingham lay under the ocean. In the Jurassic, monstrous marine reptiles like ichthyosaurs and plesiosaurs hunted ammonites and belemnites, relatives of modern squid, while giant dinosaurs lived on nearby islands. Jurassic marine fossils are known from across England, from Dorset to Yorkshire, including from close to Birmingham, and can also be seen in the Lapworth Museum.
Fossils are important therefore, because they allow us to reconstruct dramatic environmental changes across Earth history. However, fossils can also help us predict the future. One of the key messages of Blue Planet II has been the influence of humans on the oceans. At Birmingham, our micropalaeontologists and palaeoclimatologists use chemical data locked inside fossil plankton collected from drill cores through the ocean floor to reconstruct climate and environmental change in the past, which, in turn, can help us better model how climate will change in the future, and how life in the ocean will respond. As palaeontologists often like to say, the past may represent the key to the future.