WAnDeRinG NOStRiL

Muse, Mar 2005

Scientists report in the journal Nature that they have found a 400-million-year-old fish that has nostrils in its upper teeth. Most modern fish have four nostrils, two on each side of their heads. Water flows through the front nostril into a little sac that holds the organs of smell and then out through the back nostril.

So the fish can't breathe through its nose. Land animals, including people, also have four nostrils, two on the outside and two that open into the throat. So unlike fish we can breathe through our noses. Maybe the front fish-nostrils became our outside nostrils and the back fish-nostrils became the nostrils that open into our throats. To move into place, however, the back nostrils would have had to cross the barrier of the teeth and this seemed unlikely. But the newly discovered fossil proves it actually happened. The poor fish has nostrils in the fish equivalent of the gaps between our front teeth and our canines. Bet it had trouble getting dates.