Dunedin is home to the world's largest single group of researchers studying ancient marine mammal evolution, and high-profile publications about Otago marine fossils are boosting the region's international image, scientists say.

Prof Ewan Fordyce, of the University of Otago's geology department, was working largely by himself when he joined the staff at Otago and started researching ancient marine creatures 30 years ago.

These days he is supervising seven PhD students, all in the same field.

These fellow researchers comprise a kind of mini-United Nations, hailing from the United States, Mexico, Austria, Switzerland, Taiwan, Japan and Brazil.

The researchers said they were studying at Otago because of Prof Fordyce's international reputation. Several added that the North Otago-South Canterbury area was regarded as one of the top five areas in the world for continuing discovery of ancient marine fossils.

High-profile research by Prof Fordyce about ancient ''giant'' penguin fossils, published last year, and more recent discoveries involving the pygmy right whale by Prof Fordyce and doctoral student Felix Marx have sparked extensive international media coverage. The research was clearly boosting the international profile of Dunedin and Otago and highlighting North Otago's standing as a hot spot for ancient biodiversity, he said.

''I think it's great.''

All the doctoral students were high-quality scholars and working with them was a ''real privilege'' and ''hugely stimulating''.

The development of a group added to scientific advances in the field and reflected the University of Otago's strong focus on postgraduate research and its support of scholarship. The Royal Society of New Zealand recently awarded Prof Fordyce the Hutton Medal for research excellence, saying his research had placed New Zealand ''at the forefront of international research in the field''.

He has also contributed to the development of the Vanished World Trail in North Otago.

The research produced ''multiple benefits'', including for the university, which benefited from ''publicity about interesting ancient life'', and there had also been tourism-related publicity in North Otago, he said.

- john.gibb@odt.co.nz