Quinkana

Scientific name: Quinkana fortirostrum Scientific classification: Phylum: Chordata Class: Reptilia Order: Crocodilia Family: Crocodylidae When did it become extinct? The most recent Quinkana remains are around 40,000 years old.

Where did it live? Quinkana was an Australian reptile.

Crocodylidae Body
Quinkana—Quinkana was one of a number of unusual, land-dwelling crocodiles that roamed Australia and the islands of the South Pacific for many millions of years. (Renata Cunha)

In 1970, a caver exploring Tea Tree Cave in north Queensland, Australia, discovered part of the skull of a reptile lying upside down on the cave floor about 60 m from the entrance. Realizing that the skull was something special, she reported her find, and paleontologists returned to the cave to take a look at the skull. The caver had stumbled across the remains of a long-dead, land-dwelling crocodile that was later described and given the name Quinkana.

These reptiles, known as mekosuchine crocodiles, are known only from Australia and the South Pacific, and all of them are extinct. The crocodilians with which we are familiar are all amphibious animals that spend nearly all their time in or near water. They are excellent swimmers and remain submerged for long periods of time; however, on land, they can be quite lumbering. The legs of a crocodile splay out to the sides of the large body, and as a result, they are not very effective at supporting the reptile's weight. Also, legs that sprout from the side of the body are not very good when it comes to long-distance walking or running. To make any progress on land, a crocodile moves in a snakelike fashion, with its spine flexing in a horizontal plane, allowing its limbs to gain ground. This movement squeezes the lungs, and if the reptile moves at anything more than a walking pace, it quickly becomes breathless.

The body plan of the Quinkana was very different from that of living crocodiles. No limb bones of this animal have ever been found, but similar, yet more ancient crocodiles had relatively long legs that were able to support more of the animal's weight. This arrangement was much better suited to a life on land compared with the crocodiles we know today. It's doubtful that these reptiles were capable of high-speed, long-distance pursuits, but over short distances, they must have been quite deadly.

The fossil record of Quinkana is not fantastic, but from the remains we do have, it is possible to estimate the size of this beast—estimates run from 2 m all the way up to 5 m—but the living animal was probably around 3 m long. A 3-m-long, terrestrial crocodile must have been quite an animal and surely an effective predator. The crocodiles are all meat eaters, and Quinkana was no different. However, unlike today's crocodilians, which have conical teeth, Quinkana jaws were lined with lots of curved, bladelike teeth that were effective tools for slashing at prey.

Exactly what this reptile hunted and how it hunted them is a mystery, but the Komodo dragon gives us valuable insight on the hunting and feeding behavior of a giant reptile. Quinkana's Australia was a very different land to the place we know today. The Australian megafauna—a myriad of extinct beasts, some of them huge—once roamed this southern landmass, and many of these animals were fair game for Quinkana. Marsupials like diprotodons—giant, wombatlike animals—fell prey to this crocodile. Although Quinkana was better adapted for a life on land than the crocodilians we know today, it probably still spent a good deal of its time near sources of water as these attracted large numbers of herbivorous marsupials and other animals on which this reptile could have preyed, including giant birds. The Quinkana probably used ambush tactics to surprise its prey. Using undergrowth as cover, the crocodile may have stalked to within striking distance of its victim using its excellent sense of smell and then, when its quarry was within range, it burst from cover with an explosive turn of speed. Lunging at the prey with its mouth open, the jaws snapped shut on the victim.

Many of the modern crocodile species can take very large prey; they do this by dragging the unfortunate animal into the water and drowning it. Quinkana was more of a landlubber, and killing large animals without the advantage of water was probably very difficult. If it latched its powerful jaws onto the hind leg of something like a diprotodon, it may have found itself in serious trouble as an enraged, 3-tonne marsupial would have been able to inflict serious injury on a 250-kg reptile. With this limitation in mind, perhaps Quinkana had to be content with preying on smaller animals that were killed with a simple snap of the jaws, or with hamstringing larger prey and tracking them to their deaths, a similar technique to that employed by the Komodo dragon.

The most recent Quinkana remains are around 40,000 years old, and as is the case for most extinct animals from this period, we have no accurate idea of exactly when this species died out. It may have been around up until very recent times, but until we find the bones, we'll never know for sure. Australian Aborigines undoubtedly came face-to-face with Quinkana, and unfortunate individuals may have even fallen prey to it. To what extent humans hunted this reptile, if at all, is unknown, but such a large, land-dwelling animal may have been hunted by humans at some point in the past.

We do know that the most recent bones of this animal come from a time in Australia's history that is marked by the disappearance of many of its amazing animals. Around this time, global cooling was gripping the planet, and although Australia was never buried beneath ice, weather systems the world over were affected. Rains failed, and Australia dried out. Humans may have also modified the habitats of Australia by starting bushfires to clear undergrowth. In combination, climate change and human activity caused the Australian vegetation to die back, and the herbivores began to disappear as their food dwindled. With prey becoming scarcer and scarcer, predators like Quinkana were also hit hard, and they, too, eventually became extinct.

♦ There were once several species of mekosuchine crocodile living in Australia and the South Pacific. The remains of these animals have been found on numerous islands in the South Pacific, but they probably didn't get to these islands by swimming as it is thought that they had no tolerance to saltwater. Perhaps, like smaller reptiles, they were carried between the islands on rafts of vegetation that were broken away by storms and floods. It is thought that Vanuatu and New Caledonia were probably the last refuges of these reptiles, and it is very likely that they survived on these islands until the arrival of humans in quite recent times.

♦ Other mekosuchine crocodiles, close relatives of Quinkana, have also been discovered in Australia. Some of these remains are around 24 million years old, which shows that Quinkana and its relatives were a successful group of animals.

♦ Over the last 50 million years or so, at least five other groups of crocodiles have stalked the land, and for a while, some of them competed with mammals in North America and Asia for the supremacy of terrestrial habitats following the demise of the dinosaurs.

♦ The name Quinkana comes from the Aboriginal word quinkan. To some of the indigenous people of Australia's Cape York Peninsula, quinkans are humanoid spirits that live in caves and other dark places.

Further Reading: Molnar, R.E. "Crocodile with Laterally Compressed Snout: First Find in Australia." Science 197 (1977): 62-64.

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Responses

  • Helmi
    Why has quinkana become extinct?
    8 years ago
  • IMPI
    Why did the quinkana evolve?
    5 years ago
  • Temesgen Isaias
    Where did Quinkana's live?
    5 years ago
  • ferdinand
    How did the quinkana reptile become extinct?
    2 years ago
  • Ilse Waltari
    Why it was 25 millon years ago did quinkana became extinct?
    8 months ago
  • prudenzio
    How did quinkanas die?
    8 months ago
  • miranda
    What is a quinkana;s home?
    8 months ago

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