(page 2)

    Wells, Horton and Rodgers, (1982) have conducted studies of the morphology and development of wear patterns on the teeth of the species Thylacoleo carnifex.  They examined the striations produced by the grinding of food against the tooth enamel of known carnivores and herbivores and compared their findings with similar marks on the fossil teeth of Thylacoleo.  The wear patterns created by food passing down the enamel surface of the Thylacoleo teeth were similar to those present on the teeth of known carnivores but were not like those seen on herbivore teeth.  They resolved that the mandibular (lower) teeth retained a stabbing or piercing action, while the maxillary (upper) teeth functioned as both an anvil against which food is held and a "stone" against which the lowers are sharpened. Thylacoleo's  large premolars have a crescent-shaped slicing edge.  As these
skull of Thylacoleo
The enormous upper incisor teeth are well preserved and easily visible in this specimen of a Thylacoleo skull.  The reddish ochre colouration of this fossil is caused by a thin coating of silt particles rich in iron oxide.  Most of the cave fossils found in South Australia exhibit this characteristic.  If the encrustation is completely removed, such bones are often surprisingly white, and have the appearance of being quite recent.
edges pass each other during a bit, all the shearing forces are directed upon two converging points.This action is further emphasized by the fine serrated enamel margins of the teeth, which generate an effect similar to the cutting edge of a steak knife.

    Also, wear on the maxillary incisors created a blunted, semi-circular wear surface; in contrast, wear on the mandibular incisors held a sharp triangular outline from which fine, serrated ridges descended.  Examination of the jaw mechanics of the complete Thylacoleo material indicates a possum-like jaw musculature designed for stabbing with the mandibular incisors and slicing with the enormous premolars.  All evidence suggests a carnivorous marsupial of diprotodontid ancestry, not a plant-eater.

    The adaptations of Thylacoleo's limb were for climbing and gripping rather than running and walking, while the absence of interlocking canines as a method of holding prey was compensated for by the large, hooded claw of the thumb. Thylacoleo may well have seized prey by grasping it with its powerful hands, then killed it by strangulation or suffocation in a similar manner as do lions and cheetahs (Schaller, 1972); combined use of incisors and premolars would quickly strip the prey's skeleton of hide and flesh.

    Solid evidence of thylacoleonid predation has come from examinations of incised bones initially reported from Queensland (De Vis, 1883) and Victoria (Spencer and Walcott, 1911) and more recently from Lancefield in Victoria (Horton et al., 1979; Horton and Wright, 1981).  Horton and Wright (1981) studied deep v-shaped incisions on ribs and limb bones of kangaroos and made note that "The Lancefield bones suggest that the species (Thylacoleo) was a meat-eater and give no indication that it was a bone-crusher".  Their proposition gains support from the absence of completely severed bones in coproloites (scats), characteristic of the bone-eating and crushing Tasmanian devil (Sarcophilus harrisii).

    What animals were preyed upon by Thylacoleo?  Wells, Horton and Rodgers (1982) note that the animal's size itself makes it an unlikely predator of arboreal species, which are capable of moving through the highest branches with ease.

    The remains of Thylacoleo are often found in association with those of the extinct leaf-eating kangaroos of the genus Sthenurus.  Possibly, Thylacoleo preyed upon these and other kangaroo species and dragged its prey into trees, as does the leopard, removing it from the reach of scavenging animals such as the Tasmanian devil.  This view harmonizes well with all of the available evidence and provides a niche for a carnivore, which avoids competition with the thylacine (Thylacinus) the only other large predatory Australian marsupial known to have existed.

    Recent findings of fossil material

mandible section of Sthenurus
Mandible section of Sthenurus, an extinct genus of large kangaroos from the Pleistocene epoch.  Could this and 
other macropods have been the main prey of Thylacoleo
This specimen is from the Wellington Caves of New 
South Wales.  Length - 125 mm.
have extended the geographic distribution of Thylacoleo to the Pleistocene deposits of the Lake Eyre Basin; indeed it is present in most Late Pleistocene faunas throughout the whole of the Australian continent.  With the exception of the Victoria Cave Deposit at Naracoorte (Wells, et al., 1984), its numbers are usually low, which is in agreement with an animal filling the niche of top carnivore. Thylacoleo appears to have vanished along with many of the large marsupial herbivores during a time of great aridity which occurred about 18,000 years ago.  It was a period when the great ice sheets of the northern hemisphere reached their maximum.
life reconstructions of sthenurine kangaroos - Frank Knight
Life reconstructions of large, leaf-eating sthenurine kangaroos from the Pleistocene deposits of Lake Callabonna in South Australia: Sthenurus tindalei (background), and the much larger Sthenurus stirlingi in the foreground.  Courtesy: Frank Knight.

    Until quite recently, Thylacoleo carnifex was the only representative of the family Thylacoleonidae, but discoveries in mid-Tertiary sediments of Queensland, the Northern Territory and South Australia (Archer and Wade, 1976; Archer and Rich, 1982; Clemens and Plane, 1974; Pledge, 1977) indicate an older diversification of these fascinating marsupial carnivores (Archer and Dawson, 1982).  Presently, these earlier species are known mainly from teeth, skull and jaw fragments.  While much smaller in dimension than T. carnifex, species of the Tertiary, such as Wakaleo alcootensis, Wakaleo oldfieldi, Wakaleo vanderleuri (mid-Miocene) and T. hill (? Pliocene), all exhibit the same characteristic slicing premolars of their much larger Pleistocene relative.

Acknowledgement: This subsection of Thylacoleo Revealed has been referenced (in part) from: RICH, P. V., VAN TETS, G. F., and KNIGHT, F., 1985. "Kadimakara - Extinct Vertebrates of Australia". Pioneer Design Studio, Lilydale, VIC. pp. 225-29.
back to: Presenting Thylacoleo carnifex (page 1) return to the introduction forward to: About Australia and the Marsupials (page 1)

Website copyright © C. Campbell's NATURAL WORLDS.
Photographs and other illustrations (where indicated) are © C. Campbell's NATURAL WORLDS.
Other photos and images are © their respective owners.