Another interesting feature of Kunbarrasaurus is the evidence
of a parrot-like beak. Small foramina bountifully dot the bone
surface along its jaw. These foramina are also observed along the
jaws of modern-day birds and turtles.
From observations of these modern creatures we know that
these foramina allow vessels to travel through bone, delivering
blood to the beak. Beaks are constantly being ground down as
a result of foraging, grabbing and grinding food, and thus –
similar to ingernails – they need be continually nourished and
grown.
Evidence of beaks is relatively common among most herbiv-
orous dinosaurs. Direct evidence in ankylosaurs, however, is
not so common, most likely due to the enormous amount of
bone remodelling on the skull.Inner Headspace
The CT scanning and 3D reconstruction of Kunbarrasaurus
raised just as many questions as answers. Initially, despite its
extraordinary preservation, the internal structures of the skull
were diicult to interpret due to minerals in the rock – most
likely calcite, which has a similar density to fossil bone – that
still occupy the internal spaces of the skull. Once this was over-
come the inner workings of its headspace could be reconstructed.
The features found within the nasal cavity space of Kunbar-
rasaurusresulted in two potential scenarios to describe its
airways. The irst was a simple arch from the nostrils to the
throat, while the second involved a passage with a single loop.
So far only two other ankylosaur skulls have undergone a
similar analysis.Euoplocephalusand Edmontoniaare highly
advanced ankylosaurs, and both have highly convoluted, multi-
looping nasal passages unlike anything seen in other dinosaurs.
Thus the airways of Kunbarrasaurusare comparatively more
complicated than other dinosaurs but less so than other anky-
losaurs.
The North American ankylosaur’s rollercoaster-like airways
are thought to have evolved to help control the temperature
of the brain. These ankylosaurs sported very heavy armour and
would have struggled to keep cool. Their uniquely-shaped
airways would also have helped to retain water and may also
have been used to create loud bellows. Kunbarrasauruswasn’t
as heavily armoured as other ankylosaurs, and thus may not
have needed such a highly elaborate air-conditioning system.
The inner ear of Kunbarrasaurusis extremely large relative
to the size of the skull, as well as with other ankylosaurs. Its
shape is unlike that of any dinosaur yet known and is more
similar to that of a turtle or tuatara. The curious array of struc-
tures observed for Kunbarrasaurus– a spherical shape, short
semi-circular canals and unossiied portions of the cochlear
region – suggest possible functions that are incomprehensible
at the moment.22 | JUNE 2016
The skull of Kunbarrasaurus ieversi, with reconstruction revealing
its parrot-like beak.A 3D reconstruction of the cavities within the skull of
Kunbarrasaurus ieversi and the North American ankylosaurs
Edmontoniaand Euoplocephalus. Yellow: the nasal cavity. Pink:
the olfactory region of the nasal cavity. Purple: the brain. Light
pink: the ear. Red arrowed-lines: the direction of the airways.