The world’s first fussy eaters?

by Dr Imran Rahman, Research Fellow

I have just returned from visiting colleagues at Vanderbilt University in Nashville, Tennessee. Nashville is the home of country music, hot chicken and, most importantly for my work, a brand new CT scanner. Together with Drs Simon Darroch, Marc Laflamme and Rachel Racicot, I used the CT scanner to create 3-D models of 560-million-year-old fossils which will be used to learn more about how such ancient organisms lived and fed.

These fossils are some of the strangest ever described. They come from the ‘Ediacara biota’, which is approximately 542 to 600 million years old. These include the first large organisms on Earth, some of which might be early animals, but placing these fossils in their correct place in the tree of life is extremely controversial. In fact, despite extensive study by palaeontologists for many years, we know very little about what these organisms were like when they were alive.

In order to better understand these enigmatic fossils, we used Simon’s CT scanner to study them. The scanner works by using X-rays to create cross-sectional images through the specimen, which can be then used to digitally reconstruct it in 3D. We scanned a range of different fossils and were able to describe their morphology in exceptional detail, as shown in the image below.

These 3D reconstructions will serve as a basis for computer simulations of water flow around the fossils, which will allow us to evaluate ideas about how these organisms might have fed. Research we carried out last year suggested that some Ediacaran organisms may have fed in a more complex way than previously thought, and we would like to test if this applies to other species from the same time period.

Simon, an Assistant Professor in Vanderbilt’s Department of Earth and Environmental Sciences, brought us together to carry out this research. We will also be working closely with Simon’s Grad Student, Brandt Gibson, who is creating 3D models of fossils using computer graphics software. Ultimately, we hope to gain a better understanding of Ediacaran ecosystems, which will provide important new insights into the early evolution of complex life.