The first mother: how our deep ancestors lived, loved and died: 2010 winner of the Malcolm McIntosh Prize for Physical Scientist of the Year

Katherine Trinajstic

Three hundred and eighty million years ago, on the Gogo Barrier Reef in what is now the Kimberley Ranges, our early ancestors were developing teeth, jaws, limbs, and even a womb.

It was a critical period in evolution, shortly before a mass extinction, and as our vertebrate ancestors took their first steps on land. It was also when many of our oil and gas reserves were laid down.

It is a period in time that Kate Trinajstic has made her own through her discovery that the finest Gogo fish fossils are more than perfectly preserved bones—their muscles and internal organs have also been fossilised. Today she is using synchrotron light and CT scanning to virtually dissect these ancient fossils and discover how fish developed teeth, jaws and a womb.

Her work is important, not just to our understanding of how life on Earth has evolved and responded to extinction events. She is also helping in the search for new oil and gas reserves.

For her early career achievements in palaeontology, Katherine Trinajstic receives the 2010 Malcolm McIntosh Prize for Physical Scientist of the Year.

Kate Trinajstic’s entry into palaeontology was entirely fortuitous. As a girl living in northwest Sydney, she watched the nearby dairy farms turn into Macquarie University. Kate was curious about science and the academic world but her teachers didn’t regard research as an appropriate career for young women. So she turned to nursing. Some years later her husband persuaded her to do a science degree, which she completed at Murdoch University.

During her Honours year she was a volunteer at the Western Australian Museum where palaeontologist John Long introduced her to the Gogo fish and encouraged her to do a PhD.

Katherine Trinajstic, winner of the 2010 Malcolm McIntosh Prize for Physical Scientist of the Year (photo credit: Ron D’Raine)

The fish from the Gogo Reef were identified in 1940. About 380 million years ago in what is now the Kimberley Ranges in Western Australia, there was a vast barrier reef. In one part, for reasons that are still unclear, large numbers of fish died and sank to the sea bottom between the reef ledges where they were buried relatively intact. Protective limestone balls formed around them and preserved them over millions of years.

Today, these limestone balls are being exposed by erosion. Tap them with a hammer and about one in fifty cracks open to reveal a fossilised fish. When treated with acetic acid (vinegar), the surrounding rock dissolves, leaving only their bones.

Scientists have been using this technique on the Gogo fish since the 1950s. But in the course of her research looking at hundreds of fish, Kate began to see what looked like muscle fibres between the bones. Her colleagues were sceptical, but she persevered and proved to them that they had been destroying fossil structure with the acetic acid.

That led to a new challenge. How could you study these whole fossil fish without destroying them? Kate turned to X-rays and the latest medical imaging technology to peer inside the fossils and dissect them virtually.

Today she uses a unique CT scanner at the Australian National University with a 3-D resolution of two thousandths of a millimetre. She also uses the giant European Synchrotron Research Facility in Grenoble and its smaller cousin, the Australian Synchrotron in Melbourne.

Perhaps the biggest discovery was the ‘mother fish’ which had an umbilical cord still attached to its embryonic offspring. This was a vertebrate giving birth to live young some two hundred million years earlier than previously thought. And this discovery has given insight to the behaviour of the Gogo fishes, because internal reproduction implies some sort of mating procedure.

Now she can distinguish the sexes, Kate has shown that the Gogo specimens include many females and few of the smaller males. The females probably schooled while the males were solitary.

Now, with her team at Curtin University, Kate is looking for biomolecules—remnants of muscle and bone proteins. She wants to know if they have a similar structure to those in modern fishes.

She is also developing tools for the oil company Chevron to help it date core samples rapidly and accurately in its search for new oil and gas reserves.

Kate still remembers finding her first fossil and the excitement of “Cracking open a rock and seeing something that’s 380 million years old, that no-one has seen before.”


2000 PhD (Geology), The University of Western Australia, Perth
1996 Bachelor of Science (Honours), Murdoch University, Perth

Career highlights, awards, fellowships and grants

2008-present Curtin Research Fellow, Western Australian Organic Isotope Geochemistry Centre, Department of Chemistry, Curtin University of Technology, Perth
2009-present Research Associate (Honorary), The University of Western Australia, School of Earth and Environment, Perth
2000-present Research Associate (Honorary), Museum of Western Australia, Earth and Planetary Sciences, Perth
2010-2012 Natural Environment Research Council, UK, Grant: Teeth and jaws: evolutionary emergence of a model organogenic system and adaptive radiation of gnathostomes
2010-2012 Australian Research Council (ARC) Discovery Project: Origin of jaws – the greatest unsolved mystery of early vertebrate evolution. K Trinajstic, G Young, J Long, T Senden, C Burrow
2010 ARC Linkage Infrastructure Equipment Facilities Project: In-vivo Multispectral and X-ray Micro-CT Imaging – Founding a Western Australian small animal imaging core facility
2009 Top Ten New Species Discovery Award, International Institute for Species Exploration, Arizona University, USAfs
2008 Visiting Researcher, Muséum national d’Histoire naturelle, Paris, France
2007 Whitley Award (Highly Commended) for technical writing, Linnaean Society of New South Wales
2005-2008 ARC Research Fellow, School of Earth and Geographical Sciences, The University of Western Australia, Perth
2003 Dorothy Hill Award, Australian Academy of Sciences
2002-2004 Research Fellow, The University of Western Australia, Perth
2000-2001 Postdoctoral Research Fellow, The University of Western Australia, Perth
2000 Visiting Researcher, University of Iowa, USA
1999 Jubilee Award, Geosciences Australia

Research highlights

  • Re-evaluated Gogo fossils showing that many fossils thought to be new species were in fact variants of existing species
  • Discovered fossils of primitive sharks and jawless fish in the Canning Basin of WA
  • Co-discovered the oldest vertebrate fossil muscle tissue
  • Co-discovered the earliest vertebrate fossil embryos
  • First use of synchrotron imaging and CT scanning techniques in fossil analysis of Gogo fish.

Header image: Katherine Trinajstic, winner of the 2010 Malcolm McIntosh Prize for Physical Scientist of the Year (photo credit: Ron D’Raine)