A scientist from Queen’s is among a team of researchers to have discovered a rare fossil called Kulindroplax. It is the missing link between two mollusc groups and is revealed in a 3D computer model in research published last week in the journal Nature.
Dr Julia Sigwart from Queen’s School of Biological Sciences, along with researchers from Imperial College London, the Universities of Oxford, Leicester and Yale, have unearthed the worm-like partly shelled Kulindroplax, which they have modelled in a 3D computer animation.
Dr Sigwart, from Queen’s, said: “Kulidroplax is a fossil creature unlike any living animal. We think its nearest relatives are the chitons, which are still alive today and which include more than 10 species living in Britain and Ireland. We do a lot of research on living chitons in the Queen's University Marine Laboratory, to understand what life may have been like for their fossil ancestors, and what how future climate change may affect them.”
Dr Mark Sutton, lead author from the Department of Earth Science and Engineering at Imperial College London, said: “Most people don’t realise that molluscs, which have been around for hundreds of millions of years, are an extremely rich and diverse branch of life on Earth. Just as tracing a long lost uncle is important for developing a more complete family tree, unearthing this extremely rare and ancient Kulindroplax fossil is helping us to understand the relationship between two mollusc groups, which is also helping us to understand how molluscs have evolved on Earth.”
For over 20 years, scientists have debated the evolutionary relationship between two groups of molluscs called the aplacophorans, which are carnivorous, worm-like, sea-living creatures, and the chitons, which are molluscs that have shell plates for armour and live in the sea or seashore – both still live in Earth’s oceans today.
The researchers in today’s study analysed the 3D model of Kulindroplax and discovered that it had the worm-like body of the aplacophorans, but was partly shelled like the chitons. This combination of both features confirmed to the team that that aplacophorans and chitons are closely related. Furthermore, the researchers believe that their 3D fossil is the missing link that shows how the worm-like aplacophorans evolved from chiton-like ancestors by losing their shells, providing fresh insight into the mollusc evolutionary tree.
The researchers discovered the Kulindroplax fossil, which is the size of a small caterpillar, in a deposit called the Herefordshire Lagerstätte. This deposit was formed when a cloud of volcanic ash settled through the Siluian seas and entombed a range of species, including Kulindroplax, as almost perfectly preserved fossils.
In order to develop their 3D animation, the team cut the Kulindroplax fossil into 1300 slices, taking digital images of each one, which were fed into a computer. The researchers in the study say this method provides unprecedented detail from the fossils, enabling them to analyse features that have been previously unseen.
|Period||09 Oct 2012|
Title SyncNI - Mollusc missing link revealed in 3D Date 09/10/2012 Persons Julia Sigwart