High Energy X-Ray Reveals Structure of Teeth and Bones

A new tool, a cross science collaboration and a new revelation on the evolution. A latest study by the Palaeontologist from Bristol Natural History Museum and Curtin University, Australia in collaboration  with the physicists from Switzerland discovers that the earliest jawed vertebrates had teeth and they evolved along with, or soon after the evolution of jaws.

In order to support their finding they conducted a study on jaws of a primitive jawed fish called Compagopiscis.

All living jawed vertebrates have teeth but the assumption till now was that the first jawed vertebrates lacked gnashers, rather used scissor like jaw bones to capture their prey.

However, high energy X rays (normally a scientific tool of physicists) at the Swiss Light Source at the Paul Scherrer Institut in Switzerland were deployed by the research team to study the fossils of Compagopiscis. The new technique revealed the structure and development of teeth and bones.

Lead author, Dr Martin Ruecklin of the University of Bristol said: "We were able to visualise every tissue, cell and growth line within the bony jaws, allowing us to study the development of the jaws and teeth. We could then make comparisons with the embryology of living vertebrates, thus demonstrating that placoderms possessed teeth."

Co-author, Professor Philip Donoghue of the University of Bristol's School of Earth Sciences said: "This is solid evidence for the presence of teeth in these first jawed vertebrates and solves the debate on the origin of teeth."

Dr Zerina Johanson from the Natural History Museum said: "These wonderfully preserved fossils from Australia yield many secrets of our evolutionary ancestry but research has been held back waiting for the kind of non-destructive technology that we used in this study. Without the collaborations between palaeontologists and physicists, our evolutionary history would remain hidden in the rocks."

Professor Marco Stampanoni of the Paul Scherrer Institut said: "We performed non-invasive 3D microscopy on the sample using synchrotron radiation, a very powerful X-ray source. This technique allows us to obtain a perfect digital model and very detailed insight views of the old fossil without destroying it. Normally, our method delivers very high spatial resolution on tiny samples. For this experiment we modified our setup and reconstruction algorithms in order to expand the field of view significantly while keeping the spatial resolution high."

The study was published in October 17 in Nature.