200 NZ Fossils Profiled In New Photographic Guide

22 May 2013

200 NZ Fossils Profiled In New Photographic Guide

A new photographic guide of New Zealand fossils is expected to become a landmark reference for local fossil hunters for many years.

The 140-page book has been written by five GNS Science paleontologists to help the public identify fossils they are likely to encounter. It is part of the New Holland Publications series of New Zealand photographic guide books.

It focuses on about 200 animal and plant fossils commonly found in New Zealand. It covers a wide geological time scale - from 514 million years (Cambrian time) to the present. This includes representative fossils from the Paleozoic, Mesozoic, and Cenozoic periods.

As well as a colour photo of each fossil, the book features a narrative with information about the fossil and its place in the historical record. The book starts with the oldest fossils and ends with the youngest. Each time period has a different colour band on the edges of the pages.

Co-author Hamish Campbell, of GNS Science, said there was no other book like it.

“The nearest thing is a book with black and white photos of fossils published in 1981. This book complements the 1981 book and they both enable us to see something of the amazing history of life in New Zealand,” Dr Campbell said.

“We’ve excluded the rare fossils and focused on fossils that people are likely to encounter when they are out fossicking. And because of that, most of the fossils are from our younger Cenozoic rocks deposited during the past 65 million years.”

Certain conditions were needed to ensure the preservation of fossils. They needed to be buried in an environment that limits oxygen, bacteria, radiation, and mechanical abrasion.

“If those four things are excluded, then you can have almost perfect preservation.”

Dr Campbell said most New Zealand fossils were marine in origin and this reflected the fact that New Zealand had been substantially pushed up out of the sea only in the last 23 million years.

“A result of being pushed up is that we see large areas of seafloor exposed in many parts of New Zealand. A good example is the mudstone that dominates eastern and central parts of the North Island.”

The South Island had been pushed up faster and for a longer period, and consequently many South Island rocks were older than those in the north, and they contained older fossils.

The oldest rocks in the North Island were about 275 million years old, whereas in the South Island, the oldest rocks were about 510 million years.

“With uplift, much of the younger marine sediments in the South Island have been eroded away and that has removed many of the younger fossils.”

Dr Campbell’s favourite time period is the Mesozoic – 252 to 65 million years ago.

“As you travel further back in time, the animals you encounter are much more different. In the Mesozoic, there is almost nothing that is familiar in today’s terms. I like the fact that the life forms from this period are so different.

“For a small country, New Zealand is very well endowed with marine sediments which tend to preserve fossils very well, particularly shelly fossils.”

New Zealand’s marine fossil record was representative of about 40 percent of all shelly marine organisms that had lived in the past 65 million years, Dr Campbell said.

“In a global sense, that is exceptional and it’s why New Zealand’s fossil record is seen as so important in understanding the last 65 million years of life on Earth.”

Dr Campbell said the book would have lasting value and be a useful reference for many years to come.

He added that the book complemented The Kiwi Fossil Hunters Handbook, written by James Crampton and Marianna Terezow and published in 2010. It describes about 28 locations in New Zealand where fossils can be found fairly easily.

As well as Dr Campbell, the other co-authors of the photographic guide were Dr Alan Beu, Dr James Crampton, Dr Liz Kennedy, and photographer Marianna Terezow.

ENDS

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