University of Otago geologist Prof Ewan Fordyce inspects a recently studied dolphin skull belonging to a previously unknown extinct species. Photo supplied.
The discovery of a previously unknown dolphin species
highlights the South Island's growing international
reputation as a hot spot for finding ancient marine mammal
fossils, Prof Ewan Fordyce says.
The ancient, but newly recognised, dolphin, called Papahu
taitapu, is the first of its kind to be found.
And it may be closely related to ancestors of modern dolphins
and toothed whales, according to University of Otago
Prof Fordyce, of the Otago geology department, said a ''great
deal'' of important fossil material had been found in the
South Island, including in North Otago and South Canterbury,
over the years.
''In a way, it's one of the last frontiers, because many
parts of the world have been quite thoroughly investigated.
''There are a few little hot spots around the Pacific Rim
[for the finding of ancient marine mammal fossils], and we're
one of the significant ones,'' he said. The skull and one jaw
of Papahu taitapu were found in marine sedimentary
rocks in the Cape Farewell region of the northern South
Island. The researchers used the Maori name ''taitapu'' to
honour this region, and ''Papahu'' is a Maori name for
Papahu lived 19-22 million years ago, and was one of the few
dolphins reported anywhere in the world to be dated at the
start of the Miocene epoch, researchers said. Mexican-born Dr
Gabriel Aguirre and Prof Fordyce describe Papahu in
the latest issue of the US-based Journal of Vertebrate
Paleontology. The research was conducted as part of Dr
Aguirre's Otago PhD studies, completed last year.
After the Cape Farewell specimen was found about 30 years
ago, Prof Fordyce brought it south to the geology department.
But a research publication confirming the new species had
been possible only after Dr Aguirre had recently devoted an
intense period of study to the fossil. Dr Aguirre said that
its skull size suggested Papahu was about 2m long, and
it had simple conical teeth.
This dolphin had ''lived at a time of global warmth, in
shallow seas around Zealandia''- an earlier geological form
of New Zealand, he said.