What does it take to have a nice smile? First of all, jaws and teeth are required. Although all vertebrates today have these two anatomical elements, until recently it was thought that the first animals with backbones lacked teeth , and only had hideous scissor-shaped jaws to capture their prey. A study published in the journal Nature reveals, however, that this hypothesis was wrong.
The team of researchers, belonging to the Paul Scherrer Institute (Switzerland) and the universities of Bristol (United Kingdom) and Curtin (Australia), studied the jaws of a primitive jaw fish called Compagopiscis . To achieve the analysis without destroying the fossil sample, it was necessary to use a modern particle accelerator: “We have performed non-invasive 3D microscopy on the sample using synchrotron radiation, a very powerful X-ray source. This technique allowed us to obtain a digital model. perfect and highly detailed views of the old fossil without destroying it, “explained Marco Stampanoni, one of the authors.
The results showed that, contrary to what was thought, our first ancestors already had teeth: “We have been able to visualize all the lines of tissues, cells and growth within the bony jaws, which has allowed us to study the development of the jaws and teeth and make comparisons with the embryology of living vertebrates, which shows that placoderms possessed teeth “, concluded Martin Ruecklin, lead author of the work. The evolutionary debate is closed, but the question of whether this primitive jawed fish sported a beautiful smile still hangs in the air …
