Kunbarrasaurus Temporal range: Early Cretaceous, 119–113 Ma |
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Reconstructions of the skull | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Dinosauria |
Order: | †Ornithischia |
Clade: | †Eurypoda |
Suborder: | †Ankylosauria |
Genus: |
†Kunbarrasaurus Leahey et al., 2015 |
Species: | †K. ieversi |
Binomial name | |
Kunbarrasaurus ieversi Leahey et al., 2015 |
Kunbarrasaurus is a genus of small herbivorous ankylosaurian dinosaur from the Cretaceous of Australia.
Kunbarrasaurus was a small armoured dinosaur, that was quadrupedal and had a long tail.
In 2015, some distinguishing traits of the skull of Kunbarrasaurus were established. The roof of the skull is almost perfectly flat, apart from a limited convex profile of the postorbital bone and the nasal bone. The edges of the skull top, formed by the prefrontal, supraorbital and postorbital bones, make a right angle with the skull sides. The supraorbital is made up of one bone instead of two or three. The prefrontal is only exposed on the skull roof and does not reach the eye socket. The nasal bone does not reach the snout side and is limited to the snout top and the large, more centrally placed, opening around the nostril. This opening, which is completely located in the nasal bone, is large compared to the maxillary part of the snout and fully accessible from above and the side. The maxilla vertically attains the full height of the skull, reaching to the prefrontal on the skull roof. The hindmost tooth is positioned under the rear edge of the eye socket. The lacrimal bone is directed vertically. The pterygoid bones do not touch each other with their rear ends at the braincase, totally separated by the basisphenoid. The quadrate is vertically oriented. The coronoid process of the lower jaw is strongly protruding. The side of the braincase largely consists of cartilage instead of bone, so that many brain nerves must have had their exits in a single large opening, rather than separate small ones. The inner ear is very large compared with the skull as a whole and differs from that of all other known Dinosauria in the ear vestibule not being separated from the brain cavity, the floor for the cochlea not being made of bone and the vestibule being so large that the semicircular canals are shortened. The skull osteoderms are flat or at most have a low keel. There are no squamosal or quadratojugal horns or bosses on the upper skull corners or the cheeks.