Gogo Fossil Sites and Inferred Scientific Significance

Long, John A., 2016, Quantifying scientific significance of a fossil site: the Gogo Fossil sites (Late Devonian, Western Australia) as a case study, Memoirs of Museum Victoria 74, pp. 5-15 : 8

The Gogo Fossil Sites and Inferred Scientific Significance

The significance of the Gogo Fossil sites were recognised in the 1960s when the acetic acid preparation technique was refined at the Natural History Museum, London by Harry Toombs (Toombs, 1948). Toombs was able to prepare 3-D skeletons of Devonian fishes out of limestone, revealing perfect 3-D shape and form. Furthermore, in recent years preservation of fossil impressions of soft tissues including muscle fibres (Trinajstic et al., 2007, 2013), nerve cells (Trinasjtic et al., 2007), umbilical structures and embryos ( Long et al., 2008, 2009, Trinajstic et al., 2014; also see fig 2C ) and alimentary structures ( Long and Trinajstic, 2010) have been identified. Examples of the 3-D preservation of Gogo fishes and embryos is shown in figure 2 . Biomarkers have recently been identified in Gogo crustaceans preserving proteins only found in living crustaceans ( Melendez et al., 2013). The real utilisation of the Gogo fossil fish fauna though is due to the clear unambiguous preservation of the bony skeletons. It has been widely utilised for detailed histological studies of early vertebrate tissues (e.g. Smith, 1977; Smith & Campbell, 1987 etc.), as well as inclusion in major phylogenetic papers analysing character distributions (Miles and Dennis, 1979; Miles and Young, 1977, Long et al., 2014). The landmark paper on transformed cladistics by Rosen et al. (1981) utilised Gogo lungfish material to press home certain points about the homology of the tetrapod choana. Today this paper has been cited nearly 400 times (Google Scholar) and remains a seminal work on the topic.

In terms of non-quantifiable highlights of the Gogo fauna’s significance, this includes a series of world first or unique occurrences of species, genera and families. The Gogo fauna contains a mostly endemic fauna of around 90% unique genera and species. It contains the world’s only known record of camuropiscid and inscisoscutid arthrodires. It also contains the highest diversity of lungfishes (c. 12 spp.) and actinopterygians (c. 5 spp.) for any site of similar age. In its high diversity of vertebrates (c. 50 spp.) it is well above any other site of similar age, including the World Heritage Miguasha site in Canada (20 fish species; Cloutier, 2010). From a purely intuitional perspective one can sense the value and degree of scientific significance of such a uniquely wellpreserved, diverse and endemic fauna is obviously high. The question is how do we measure this?

Figures

Figure 2. Examples of Gogo fish preservation (WAM = Western Australian Museum; NMV P = Museum Victoria Palaeontology Collection). A, eubrachythoracid placoderm Mcnamaraspis kaprios, the state fossil emblem of Western Australia (WAM 86.9.676, from Long, 1995). B, The tetrapodomorph fish Gogonasus andrewsae (NMV P221807). C, the ptyctodontid placoderm Austroptyctodus gardineri which has 3 embryos preserved inside it (WAM 86.9.662). D, palatal view of the lungfish ‘Chirodipterus’ australis (most likely a new genus). WAM 90.10.8. Scale bars are 1 cm.