Gogo Fish

Article | Updated 2 months ago

Mcnamaraspis kaprios
Mcnamaraspis kaprios
WA Museum

Unique Gogo fish specimens dating back about 380 million years found in the Kimberley reveal amazing amounts of information to Western Australian Museum palaeontologists and other scientists from all over the world.

Gogo concretions (limestone nodules which formed around fish skeletons) preserve fossils extremely well in their original 3D shapes. What’s more, a fossil fish skeleton is quite resistant to weak acids.

Palaeontologists take advantage of this and use acids to slowly dissolve Gogo concretions, exposing the fish skeletons trapped inside. This process takes several months and involves repeated cycles of acid digestion, rinsing, drying and application of a stabiliser.

Some Gogo fish specimens have phosphatised soft tissue preserved such as muscle fibres and, in one example, the umbilical cord!

Our knowledge of this group of extinct vertebrates has improved dramatically in recent years as a result of studies based on the world-class Gogo material found at a reef complex along the north-eastern margin of the Canning Basin in the Kimberley.

One particularly well-preserved placoderm fish fossil from this region is pictured here. It was discovered in 1986 by Dr John Long and was formally described in 1995 and named Mcnamaraspis kaprios, in honour of another palaeontologist, Dr Kenneth McNamara.

Mcnamaraspis kaprios

Mcnamaraspis kaprios
Image copyright WA Museum 

Later in 1995 it was selected as the State Fossil Emblem for Western Australia.

Sutherland Dianella Primary School initiated a campaign for Western Australia to have Australia’s first state fossil emblem.

In December 1995 Mcnamaraspis kaprios was proclaimed WA’s State Fossil Emblem and it also soon became the school’s emblem.