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Kunbarrasaurus, new anklyosaur from Lower Cretaceous of Australia (was Minmi sp.) (free pdf)



Ben Creisler
bcreisler@gmail.com

A new paper in PeerJ:

Lucy G. Leahey, Ralph E. Molnar, Kenneth Carpenter, Lawrence M. Witmer
& Steven W. Salisbury (2015)
Cranial osteology of the ankylosaurian dinosaur formerly known as
Minmi sp. (Ornithischia: Thyreophora) from the Lower Cretaceous Allaru
Mudstone of Richmond, Queensland, Australia.
PeerJ 3:e1475
doi: https://doi.org/10.7717/peerj.1475
https://peerj.com/articles/1475/



Minmi is the only known genus of ankylosaurian dinosaur from
Australia. Seven specimens are known, all from the Lower Cretaceous of
Queensland. Only two of these have been described in any detail: the
holotype specimen Minmi paravertebra from the Bungil Formation near
Roma, and a near complete skeleton from the Allaru Mudstone on
Marathon Station near Richmond, preliminarily referred to a possible
new species of Minmi. The Marathon specimen represents one of the
world’s most complete ankylosaurian skeletons and the best-preserved
dinosaurian fossil from eastern Gondwana. Moreover, among
ankylosaurians, its skull is one of only a few in which the majority
of sutures have not been obliterated by dermal ossifications or
surface remodelling. Recent preparation of the Marathon specimen has
revealed new details of the palate and narial regions, permitting a
comprehensive description and thus providing new insights cranial
osteology of a basal ankylosaurian. The skull has also undergone
computed tomography, digital segmentation and 3D computer
visualisation enabling the reconstruction of its nasal cavity and
endocranium. The airways of the Marathon specimen are more complicated
than non-ankylosaurian dinosaurs but less so than derived
ankylosaurians. The cranial (brain) endocast is superficially similar
to those of other ankylosaurians but is strongly divergent in many
important respects. The inner ear is extremely large and unlike that
of any dinosaur yet known. Based on a high number of diagnostic
differences between the skull of the Marathon specimen and other
ankylosaurians, we consider it prudent to assign this specimen to a
new genus and species of ankylosaurian. Kunbarrasaurus ieversi gen. et
sp. nov. represents the second genus of ankylosaurian from Australia
and is characterised by an unusual melange of both primitive and
derived characters, shedding new light on the evolution of the
ankylosaurian skull.