|
''Thylacoleo'' ("pouch lion") is an extinct genus of carnivorous marsupials that lived in Australia from the late Pliocene to the late Pleistocene (2 million to 46 thousand years ago). Some of these "marsupial lions" were the largest mammalian predators in Australia of that time, with ''Thylacoleo carnifex'' approaching the weight of a small lion. The estimated average weight for the species ranges from 101 to 130 kg.〔http://link.springer.com/article/10.1007%2Fs10914-013-9228-3〕 ==Description== Pound for pound, ''Thylacoleo carnifex'' had the strongest bite of any mammal species living or extinct; a ''T. carnifex'' weighing had a bite comparable to that of a 250-kg African lion, and research suggests that ''Thylacoleo'' could hunt and take prey much larger than itself.〔http://rspb.royalsocietypublishing.org/content/272/1563/619.full#ref-29〕 Larger animals it may have hunted include ''Diprotodon'' spp. and giant kangaroos. Its seems improbable that the Thylacoleo could achieve as high a bite force as a modern day Pantera Leo, however this may have been possible when taking into consideration the size of its brain and skull. Carnivores usually have rather large brains when compared to marsupials, which lessens the amount of bone that can be devoted to enhancing bite force. Thylacoleo however, is thought to have had substantially stronger muscle attachments and therefore a smaller brain. Canids possessed elongated skulls, while cats tend to possess foreshortened ones. The similarities between cat morphology and that of the Thylacoleo indicates that while though it was a marsupial, biologically it possessed greater similarities to cats, and as a result had a higher capacity for bite strength than animals within its own phyla.〔https://laelaps.wordpress.com/2007/08/31/thylacoleo-carnifex-ancient-australias-marsupial-lion/〕 It also had extremely strong fore limbs, with retractable, cat-like claws, a trait previously unseen in marsupials. ''Thylacoleo'' also possessed enormous hooded claws set on large semiopposable thumbs, which were used to capture and disembowel prey. The long muscular tail was similar to that of a kangaroo. Specialized tail bones called chevrons allowed the animal to tripod itself, and freed the front legs for slashing and grasping.〔(NOVA | Bone Diggers | Anatomy of Thylacoleo | PBS )〕 Its strong forelimbs, retracting claws, and incredibly powerful jaws mean it may have been possible for ''Thylacoleo'' to climb trees and perhaps to carry carcasses to keep the kill for itself (similar to the leopard today). Due to its unique predatory morphology, scientists repeatedly claim ''Thylacoleo'' to be the most specialized mammalian carnivore of all time.〔(Extinct Australian "Lion" Was Big Biter, Expert Says )〕 ''Thylacoleo'' had vertical shearing ‘carnassial’ cheek–teeth that are relatively larger than in any other mammalian carnivore.〔 ''Thylacoleo'' was clearly derived from the diprotodontian ancestry due to the pronounced development of upper and lower third pre-molars which functioned extreme carnassials with complementary reduction in the molar teeth row.〔Roderick T. Wells , Peter F. Murray & Steven J. Bourne (2009) Pedal morphology of the marsupial lion ''Thylacoleo carnifex'' (Diprotodontia: Thylacoleonidae) from the Pleistocene of Australia, ''Journal of Vertebrate Paleontology'', 29:4, 1335-1340, DOI: 10.1671/039.029.0424〕 They also had canines but they served little purpose as they were stubby and not very sharp.〔http://www.naturalworlds.org/thylacoleo/introducing/introducing_tc_1.htm〕 ''Thylacoleo'' was at the shoulder and about long from head to tail. The species ''T. carnifex'' is the largest, and skulls indicate they averaged , and individuals reaching were common. Fully grown, ''Thylacoleo Carnifex'' would have been close to the same size as a jaguar. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Thylacoleo」の詳細全文を読む スポンサード リンク
|