OZ fossils - The Age of the Megafauna - The Fauna - Fauna found at the Naracoorte Fossil site
Nimiokoala greystanesi was a small koala from the early Miocene of northern Australia. It probably had a backward-opening pouch, as in living koalas and wombats (an unlikely development for an arboreal animal, Evolutionary relationships member is the massive Diprotodon) are also included in Vombatiformes. Diprotodon, meaning "two forward teeth", is the largest known marsupial to have ever lived. The closest surviving relatives of Diprotodon are the wombats and the koala. However, both the small and large diprotodonts coexisted throughout the Pleistocene and the size difference is similar to other sexually dimorphic. Mapping of eight carpal characters on alternative diprotodontian is contested, and the relationships among major diprotodontian clades have been The terrestrial wombats employ their hands in a plantigrade walk and .. Alternatively , the lunatum might be simply retained in the left hand of the animal.
Possums and gliders use their hands for holding on to branches and treestems, and many species are well known for their dexterity when obtaining and handling food Nowak, The terrestrial wombats employ their hands in a plantigrade walk and for burrowing, while the secondarily arboreal koala has developed a specialized digital anatomy for climbing Lewis, Macropodines are specialized to grazing and browsing.
They forage in a characteristic plantigrade gait Croft, Macropodines only occasionally engage their hands to pull down branches as well as to fight and groom Jarman, To what extent functional diversity is reflected in carpal anatomy has been examined in detail in some mammalian groups, most notably in primates and scandentians e.
Yalden, ; Lewis, ; Sargis, In this study, we examine carpal anatomy in a large sample of diprotodontians. The results are discussed in the light of recent phylogenies, and functional aspects are considered to gain an understanding of carpal evolution in this diverse group. Camera lucida drawings were made of the carpal outlines in dorsal view. Studies of the fossils of this large rat-kangaroo suggest that it was an opportunistic carnivore and ate insects, vertebrates, fruits and soft leaves.
We have, in our illustration drawn him eating a large birds egg, perhaps belonging to the Mihirung which he might have been able to steal.
Nimiokoala greystanesi - The Australian Museum
The kangaroo-like Propleopus might have weighed 70 or so kilograms while the rat-kangaroos of today are only 3 or 4 kilos in weight. To call him a carnivore is not so bizarre when you think that the modern Musky Rat-kangaroo eats insects and the Burrowing Bettong sometimes scavenge sheep carcasses.
Propleopus all had large shearing and very stout grinding teeth so would have been able to cope with some meat in their diet. Whether they hunted for it is not so certain on evidence. Sthenurus tindalei Sthenurine kangaroos were a particular evolutionary line and form which died out in pre-history.
Sthenurine kangaroos appear to have found a niche in the open woodland of central Northern Australia as the lush tropical rainforests were beginning to decline.
Seventeen species in three genera have been described of which Procoptodon Goliah was the largest. The incisor teeth of wombats somewhat resemble those of the placental rodentsbeing adapted for gnawing tough vegetation, as well as for digging tunnels. They have massive jaws that deliver powerful, short chewing strokes, and they have open-rooted teeth that continue to grow throughout their lifetime Johnson Like many other herbivorous mammals, they have a large diastema between the incisors and the cheek teeth, which are relatively simple.
The dental formula of wombats is: Wombats have an extraordinarily slow metabolismwhich aids their survival in arid conditions McIlroy Along with their slow digestion of food, their slow metabolism means they can spend less time feeding than other grazers of comparable size and thus less time exposed outside their burrows Johnson As adaptations for a digging lifestyle, wombats have a heavy and strong pectoral girdle and broad and massive humerus, resulting in powerful forearms.
They also have broad forepaws and strong claws. The name wombat comes from the Eora Aboriginal community who were the original human inhabitants of the Sydney area. Behavior and reproduction A wombat at the Australia Zoo. Modern wombats dig extensive burrow systems with rodent-like front teeth and powerful claws. They fling soil behind them, which is moved clear of the burrow as the animal backs up Johnson The burrows may be extensive, consisting of 30 meters 98 feet or more of tunnel length, with several entrances, side tunnels, and resting chambers, and may be wide enough to allow entry by a light-built human being Johnson Indeed, many wombat burrows were explored by a year old boy inwho wrote a now-famous article on the adventure, although such explorations are strongly advised against as wombats can cause injury Johnson It is not known if extinct wombats were burrowing animals, and the giant wombats do not seem to be as well-adapted for burrowing as the three extant species Johnson Modern wombats tend to be solitary individuals, but many animals may share the same warren, although it appears they occupy different sections Johnson Although mainly crepuscular and nocturnal, feeding at night and resting in their burrows during the day, wombats will also venture out to feed on cool or overcast days.
They are not as commonly seen as many animalsbut leave ample evidence of their passage, treating fences as a minor inconvenience to be gone through or under and leaving distinctive cubic scat.
Their diet consists mostly of grassessedges, herbsbarkand roots. Wombats generally feed alone Johnson Dingos and Tasmanian Devils prey on wombats.
When attacked, wombats can summon immense reserves of strength; one defense of a wombat against a predator underground is to crush it against the roof of the tunnel. Its primary defense is its toughened rear hide with most of the posterior made of cartilage.
This, combined with its lack of a meaningful tail, makes it difficult for any predator that follows the wombat into its tunnel to bite and injure its target. Wombats generally move slowly, but when threatened they run quite fast for short periods. Wombats defend home territories centered on their burrows, and react aggressively to intruders. The common wombat occupies a range of up to 23 hectares 57 acreswhile the hairy-nosed species have much smaller ranges, of no more than four hectares ten acres McIlroy Female wombats give birth to a single young in the spring, after a gestation period lasting about 22 days Johnson