Tiny teeth evolution's sharpest
The tiny teeth of a long-extinct prehistoric fish are the sharpest that have ever been recorded, according to new research.
Research published this week in the Proceedings of the Royal Society B by scientists from Monash University and the University of Bristol showed the teeth of conodonts, a group that first appeared around 500 million years ago, were easily able to bite through the animal's food despite measuring only a millimetre in length.
The fragile nature of the tiny fossil remains of animals that died out more than 200 million years ago meant scientists had to create virtual 3D models of the material using x-rays from a particle accelerator in Japan before they could conduct thorough research.
One of the study's authors, Dr Alistair Evans of Monash University's School of Biological Sciences, said evidence suggested the conodonts were the first vertebrates to develop teeth.
“Conodonts had no other skeleton than the teeth in their mouths. These came together a bit like scissors, to slice up food,” Dr Evans said.
The research findings offered insights into the evolution of teeth in larger vertebrates, including humans.
"The conodonts took an alternative route through evolution to humans, who developed less efficient, but less breakable, blunter teeth, to which greater force can be applied by jaw muscles," Dr Evans said.
"The sharpness of conodont teeth allowed them to overcome the limitations of their small size. Since pressure is simply force applied divided by area, to increase pressure you must either increase the force or shrink the area. Conodont evolution took the latter route, allowing them to apply enough pressure to break up their food."