Tiny bones rewrite textbooks

December 13, 2006

Small but remarkable fossils found in New Zealand will prompt a major rewrite of prehistory textbooks, showing for the first time that the so-called "land of birds" was once home to mammals as well.

The tiny fossilised bones - part of a jaw and a leg - belonged to a unique, mouse-sized land animal unlike any other mammal known. They were unearthed from the rich St Bathans fossil bed, in the Central Otago region of South Island.

But the real shock to scientists was that it was there at all: until now, decades of searching had shown no hint that furry, warm-blooded animals had ever trodden on New Zealand soil, despite them having thrived so widely in other lands.

The fact that even one land mammal lived there, at least 16 million years ago, has put paid to the theory that New Zealand's diverse prehistoric bird fauna had evolved there because they had no competition from land mammals.

An international team led by Trevor Worthy, of the University of Adelaide, Alan Tennyson, of the Museum of New Zealand Te Papa Tongarewa, and Mike Archer, of the University of New South Wales, note that New Zealand separated from the ancient supercontinent of Gondwana more than 80 million years ago. The research has been published in the journal Proceedings of the National Academy of Sciences.

"This amazing find suggests that other mammals are waiting to be found there, and that New Zealand belonged to the birds only in more recent times," says Mr Worthy.

"It also suggests that New Zealand was not completely submerged, as some scientists thought, when sea levels were high about 25 to 30 million years ago."

The team believes that more mammal specimens may emerge, perhaps even species that pre-date the split between pouched marsupials and live-bearing placental mammals.

The St Bathans fossil field - which has also produced many other species of animals, including fish and birds - also promises to shed new light on climate change in the Australasian region, recording a massive shift from a warm, wet phase to a much cooler and drier period.

"This promises to be a richly rewarding fossil field and the heraldic discovery of New Zealand's first non-flying mammal represents just the first page of a fascinating new chapter in the history of the world's mammals," says Professor Archer.

The Australian Research Council recently awarded the team a $500,000 grant over the three years to further explore the St Bathans site.

Source: University of New South Wales

Explore further: Global study of seed consumption uncovers wider risk to plant species

Related Stories

Dark plumage helps birds survive on small islands

July 22, 2015

Animal populations on islands tend to develop weird traits over time, becoming big (like Galapagos tortoises) or small (like extinct dwarf elephants) or losing the ability to fly (like the flightless parrots of New Zealand).

Recommended for you

The culinary habits of the Stonehenge builders

October 13, 2015

A team of archaeologists at the University of York have revealed new insights into cuisine choices and eating habits at Durrington Walls – a Late Neolithic monument and settlement site thought to be the residence for the ...

Ancient genome from Africa sequenced for the first time

October 8, 2015

The first ancient human genome from Africa to be sequenced has revealed that a wave of migration back into Africa from Western Eurasia around 3,000 years ago was up to twice as significant as previously thought, and affected ...

Mexican site yields new details of sacrifice of Spaniards

October 9, 2015

It was one of the worst defeats in one of history's most dramatic conquests: Only a year after Hernan Cortes landed in Mexico, hundreds of people in a Spanish-led convey were captured, sacrificed and apparently eaten.

From a very old skeleton, new insights on ancient migrations

October 9, 2015

Three years ago, a group of researchers found a cave in Ethiopia with a secret: it held the 4,500-year-old remains of a man, with his head resting on a rock pillow, his hands folded under his face, and stone flake tools surrounding ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.