The enigma from Gogo

ENIGMA /ɪˈnɪɡmə,ɛˈnɪɡmə/

noun, a person or thing that is mysterious or difficult to understand.

Since 2011, there has persisted a mysterious specimen known from the Late Devonian Gogo Formation in Australia. Dubbed Cainocara enigma by authors Ken Campbell and Dick Barwick, who first studied it, they published a work entitled “A new unusual Osteichthyan fish from the Gogo Formation, Western Australia“, but considered this single specimen so strange that they could not identify it any further than some kind of bony fish…

Fast forward to 2024, and enter my dedicated and hard-working 3rd year research student, Hannah Thiele, who used CT scans of this, well, BLOB of a fossil (there really is no other way to describe it!) and specialised 3D segmenting software to solve the mystery of just what the enigma really was!

By reconstructing the internal space of this mysterious fossil, Hannah was able to identify a cranial endocast, the space inside the skull that usually houses the brain. In doing so, we could identify features that helped us to orient the specimen correctly and interpret it accurately. This meant we could solve the mystery once and for all!

We deduced that the enigma from Gogo was most likely the poorly-preserved, and heavily-weathered braincase of a lungfish. Exactly which one we don’t know, but something similar to the short snouted forms such as Chirodipterus or Holodipterus.

Hannah, together with myself and colleagues John Long (Flinders) and Joseph Bevitt (ANSTO), published a paper detailing the results earlier this year in the Canadian Journal of Zoology, with “Deciphering Cainocara enigma from the Late Devonian Gogo Formation, Australia“.

If you are keen to read more, see the news article “Missing pieces added to ancient global fish puzzle” published on Scimex. After this work, Hannah continued her study on fish brains at Flinders University, and has now commenced her PhD.