research: in the field : Long in the tooth

The fossilised remains of a new species of extinct dolphin
went on display this month at Otago Museum in Dunedin. The dolphin, believed to
be more than 5 metres long and 23 million years old, had a distinct feature
protruding from its jaw—a tusk-like tooth about 25 centimetres long. The
tooth, skull, ribs and spine of the dolphin were found last year in the
Hakataramea Valley in South Canterbury. According to Ewan Fordyce from
the University of Otago, the large tooth was probably used for fighting or for
display purposes during mating. The dolphin, he says, is a new species in the
extinct family Squalodelphidae.