Unusual new fossils from ancient rocks in Wales

Unusual new fossils from ancient rocks in Wales

What did you do during the Covid-19 lockdown?  Did you enjoy getting closer to nature and seeing new things in your local area during your daily walks?  Two of the Museum’s Honorary Research Fellows, Dr Joe Botting and Dr Lucy Muir, did just that and more, when they discovered a treasure trove of new fossils near their home in mid-Wales.  Unable to travel far or access Amgueddfa Cymru facilities to further their work on ancient life, these independent researchers crowdfunded to buy microscopes that would allow them to study their new finds in detail.  The fossils belong to a variety of different animal groups, some of them rarely fossilized because they have soft bodies with no hard shells, bones or teeth.  Joe and Lucy are working with other palaeontologists from around the world to study the fossils and decipher what they can tell us about life in Wales’ seas over 460 million years ago. 

In a paper just published in the journal Nature Communications - led by Dr Stephen Pates of Cambridge University and also involving Dr Joanna Wolfe of Harvard University, Joe, Lucy and colleagues describe two highly unusual fossils from the new site.  The fossils are tiny, entirely soft-bodied animals that resemble a bizarre creature called Opabinia, which lived in Canada over 40 million years earlier.  A similar animal called Utaurora was described from rocks of a comparable age in the USA.  Whether the Welsh fossils represent true cousins that belong in the same family as the North American creatures is uncertain, but they certainly reveal that strange ‘opabiniid’- like animals lived in the seas for much longer than previously thought and had a wider geographical range.

Where are the fossils from?

The fossils were discovered in a quarry on private land not far from Llandrindod Wells (the exact location is being kept secret to protect the site).  The rocks in which the fossils were found were laid down under the sea during the Ordovician period, over 460 million years ago, a time when what is now mid Wales was covered by an ocean, with a few volcanic islands here and there.

What kind of animals were they?

The Welsh fossils resemble strange animals known as ‘opabiniids’, until now only known from much older rocks from the Cambrian period.  They lived in the sea and were soft-bodied, with a long narrow trunk which had a row of flaps along each side, thought to have been used for swimming, and pairs of stumpy triangular legs on the underside. At one end of the trunk, there was a fan-like tail. 

Their most distinctive feature was at the other end - a long proboscis sticking out the front of the head, looking a bit like the hose of a vacuum cleaner.  In contrast to the Cambrian opabiniids, the proboscis of the Welsh species bears a row of small spines.  The proboscis is thought to have been flexible, perhaps used to pick up bits of food off the seabed and to move them to the mouth, which lay behind it on the underside of the head.  Both the legs and the proboscis were ‘annulated’, meaning they were made up of lots of ring-like segments.  However, these were not truly ‘jointed’ in the way that a crab or spider’s legs are jointed.  Opabiniids are thought to share a distant ancestor with these and other modern jointed-limbed animals known as ‘arthropods’, but weren’t direct ancestors of them.

The larger of the two fossils is 13 mm long, including a 3 mm long proboscis. The smaller one is just 3 mm, with its proboscis making up just under a third of its total length.  There are some differences between the two fossils that suggest that the smaller one may be an earlier growth stage of the larger species, or it may represent a different species entirely.  In any case, both Welsh individuals were much smaller than Opabinia, whose fossils are up to 7 cm long. 

A Welsh name for a Welsh wonder!

All species, living or extinct, have a scientific name made up of two parts, a genus name and a species name.  One of the new fossil animals has been given the scientific name Mieridduryn bonniae.  The species name is after Bonnie, niece of the owners of the land where the fossil was found and fossil fan, in recognition of the family’s support and enthusiasm for the work being carried out on the fossils.  It’s fairly common for new species to be named after people linked to their discovery or who have done a lot of work on related species. The genus name is more unusual and comes from the Welsh words for bramble, mieri and snout or proboscis, duryn.  It was inspired by the small thorn-like spines that stick out along the length of the animal’s proboscis.  It is very unusual for a scientific name to be based on the Welsh language, as traditionally most are derived from Latin or Greek words.  The name Mieridduryn will stand as a lasting tribute to the fossil’s country of origin.

It was decided that the second fossil wasn’t well enough preserved to be able to name it as either belonging to the same species as the first one, or to a different species. 

What can I do if I find an unusual-looking fossil?

As these fossils show, there are still lots of exciting new things to discover in Wales.  If you find something that looks interesting and you're not sure what it is, our Museum scientists would be happy to try to identify it for you, whether it's a fossil, rock, mineral, animal or plant.  Just send us a photo (with a coin or ruler included for scale) with details of where you found it.  You can contact us via our website or on Twitter @CardiffCurator.  We also have a number of spotters’ guides on our website, which will help you identify a lot of the more common things you’re likely to come across.