Sharks Teeth No Longer the Ancestral Tooth 

It was a bit of a surprise to me but I found out today that sharks teeth were, until now, considered the sort of tooth from which all other teeth, including our own, were derived. It had not been at the forefront of my thought, I must admit, but now I know that RECENT RESEARCH has shown that tooth patterns evolved independently many times. 

It all started with some nicely preserved acanthodian (shark precursors) jaws. Intense study of these using intense X-rays (sorry) showed that they had two types of teeth - teeth in rows and teeth in whorls. Teeth evolved in many different ways. So the shark model is not useful for dentists looking at human dental problems.

Digital models of acanthodian tooth rows (left) and tooth whorl (right) Martin Rücklin, Naturalis Biodiversity Center