Tiny Teeth of Long-Extinct Vertebrate Are Sharpest Dental Structures Ever
ScienceDaily (Mar. 14, 2012) — The tiny teeth of a long-extinct vertebrate -- with tips only two micrometres across: one twentieth the width of a human hair -- are the sharpest dental structures ever measured, new research from the University of Bristol and Monash University, Australia has found.
For 300 million years, Earth's oceans teemed with conodonts -- early vertebrates that kept their skeleton in their mouth. The elements of this skeleton look uncannily like teeth (see image) and, like teeth, they were often worn and broken during life. This evidence strongly suggests that conodonts evolved the first vertebrate dentitions.
Scientists know that conodont elements worked differently from the teeth of other animals: they are microscopic -- about 2 to 0.2 mm long -- and must have had paltry muscles to move them, with no jaws to which they could attach. So how could they possibly have worked as teeth? In a new study published March 14 in the Proceedings of the Royal Society B the Bristol and Monash University researchers answer this question.
Dr David Jones of Bristol's School of Earth Sciences, one of the study's authors, said: "The first problem is: how do you analyse such tiny teeth? The answer: with a very big machine. We created high resolution 3D models of the conodont elements using x-rays from a particle accelerator in Japan, using it like a giant CT scanner. These virtual models were examined, leaving the original specimens untouched."
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http://www.sciencedaily.com/releases/2012/03/120314125921.htm
http://en.wikipedia.org/wiki/Conodont
