Formany years palaeontologists had a fairly
simple way of working. Many of us used to dig up
fossils, photograph and draw them, describe them
and publish a paper about them. What we could
see was really all we could study.
This approach has changed dramatically in
the past decade as high technology imaging now
allows us to mine fossils for new layers of infor-
mation. This has caused a revolution in the study
of palaeontology as we can now apply various
methods to image any part of a fossil, even if it’s
still enclosed inside rock.
In 1980 during my Honours year I thought it
was pretty radical to use a high-powered engi-
neering X-ray machine to image ish fossils that
were still in rock. This gave us a hazy but useful
2D image of the unexposed part of the fossil
inside the rock, and worked well as long as the
rock layer wasn’t too thick (e.g. less than 3 cm).
Then, in the early 2000s, micro-CT scanners
arrived on the scene. The fossil spins around in
the scanner and the X-rays make hundreds of
slices through it, and these are digitally stitched
together into a high-resolution 3D image. Using
segmentation software we can then identify each
cross-section of the series and colour the different
bony elements to help identify the parts in 3D.
Other software like the feeeware Drishti avail-
able from the Australian National University’s
Vizlab allows us to see inside the rock or the fossil and make an
image showing much of the internal structure – even the cellular
details of the bone or teeth – without the time-consuming task
of segmentation.
The advent of synchrotron technology has now enabled us
to ramp up the whole micro-CT approach to powerful new
levels. Machines like the Grenoble Synchrotron in France shoot
high-powered beams through rocks containing fossils (say up
to 10 cm thick). The Australian Synchrotron can do similar
tasks, as I recently found out last month using its new Imaging
and Medical Beamline with great success. A series of amazing
papers has been produced over the past decade or so using this
method, which is becoming almost standard practice now the
more machines are becoming accessible to researchers.
So what’s next? The main limiting factor of micro-CT and
synchrotrons is the density of rock enclosing the fossils, so
important specimens inside relatively thick rocks are still the
main problem to image. Enter the new Dingo neutron beam at
the Australian National Science and Technology Organisation
in Lucas Heights. Dr Joe Bleviit has shown me preliminary
results of trials of this amazing machine on a number of fossils.
It can image through solid rock up to about 20 cm thick. Using
a concentrated beam of neutrons, it images different compo-
sitional elements in the rock. As bone has a different compo-
sition to, say, limestone or shale, the bone shows up very clearly
with resolution down to 30 μm slices. This means we now have
a powerful new tool to go back and test many signiicant fossils
to ind the missing bits of the information we need to under-
stand important evolutionary transitions.
The game has now changing rapidly. Who knows what’s
coming next? I can assure you it’s an exciting time to be a
palaeontologist.APRIL 2016|| 43John Long is Strategic Professor in Palaeontology at Flinders University, and current
President of the Society of Vertebrate Paleontology.THE FOSSIL FILE John Long
The Rise of High-Tech Palaeontology
High-tech scanners now enable palaeontologists to gain new insights from significant fossils
embedded in solid rock.
andmakean mainproblemtoimaggeEnterthenewDinggoneutronbeamatA 380-million-year-old slice of fossil lungfish being aligned for imaging at
the Australian Synchrotron's Imaging and Medical Beamline to search for
soft tissues preserved inside the rock. Credit: John Long