In Depth
Quinkana was one of the last surviving terrestrial crocodiles, and disappears from the fossil records as recently as forty thousand years ago. This disappearance also coincides with the disappearance of many of the large mammals from Australia and is thought to be a result of the first humans arriving on the continent. Even if Quinkana did not come into direct conflict with human hunters, it may have simply been out competed by them.
There are two main features of Quinkana that suggest a terrestrial lifestyle. First are the legs that are better able to support and carry the body clear off the ground. Most of the crocodiles we know today are primarily aquatic and are only able to push themselves along on their bellies. The second feature is the type of tooth. Aquatic crocodiles typically have conical teeth that are very good for holding onto struggling prey as they drown it underwater.
However, because it lived on the land, Quinkana could not use water to drown its prey, so conical teeth would be of limited use. Instead the teeth were more like knives, compressed laterally and with serrated edges. This means that a bite from Quinkana would do a lot of damage to a softer bodied prey item like a mammal. Even if the prey survived the initial attack and escaped it would probably succumb to shock and blood loss in a short space of time, meaning Quinkana would just have to bide its time until the prey was too weak to escape.
There is considerable size variation in the species of Quinkana. The type species Q. fortirostrum is the largest at five to six meters long. Earlier species of Quinkana such as Q. meboldi and Q. timara were smaller at around two meters length. Also of note is that the smaller species are also the older ones, which means that as the genus existed, individuals and newly emerging species steadily grew to larger sizes as seen by Q. fortirostrum.
Further Reading
– Pleistocene ziphodont crocodiliansof Queensland. – Record of the Australian Museum 33 (19): 803-834. – R. E. Molnar – 1981. – A new species of Quinkana Molnar (Eusuchia: Crocodylidae) from the Miocene Camfield Beds of northern Australia. – The Beagle, Records of the Museums and Art Galleries of the Northern Territory 11:145-166. – D. Megirian – 1994. – Quinkana babarra, a new species of ziphodont mekosuchine crocodile from the early Pliocene Bluff Downs Local Fauna, Northern Australia, with a revision of the genus. – Proceedings and Journal of the Linnean Society of New South Wales 116: 143–151. – P. M. A. Willis & B. Mackness – 1996. – New crocodilians from the late Oligocene White Hunter Site, Riversleigh, northwestern Queensland. – Memoirs of the Queensland Museum 41(2):423-438. – P. M. A. Willis – 1997.
