|3D representation of micro-CT scan data.|
Lungfish are the closest living relatives to tetrapods and are mainly noteworthy for their ability to breathe air. Most species don't have functioning gills and breathe with the use of complex swim bladders that act as lungs. That might sound advanced, but some species of lungfish can be very primitive. For example the Queensland lungfish hasn't changed nearly at all for millions of years and it could very well be classified as a living fossil. Lungfish also have a remarkable way of dealing with dry seasons, when pools they habitate can dry up. They dig burrows and go dormant, then slow their metabolism to extreme levels – a process called aestivation. Lungfish also tend to have long life spans.
|Queensland Lungfish. Source: wikipedia.|
The authors have used micro-CT scan to create a detailed 3D map of the fossilized skulls. These methods reveal features belonging to older Devonian lungfish and later specimen, making this a transitional fossil. The authors give a detailed description of their analysis of the fossil.
Read the published article on PLOS ONE.