57 



ON THE AFFINITIES AND HABITS OF THYLACOLEO. 

 By R. Broom, M.D., B.Sc. 



The nature of few fossil animals has been more discussed than 

 that of the remarkable extinct Australian form to which Owen 

 gave the name of Thylacoleo cariiifex. Not only has there been 

 considerable difference of opinion as to the affinities of the animal, 

 but its probable habits have been even more debated. 



The first important paper on Tliylacoleo was published by 

 Owen in 1859.* In this paper are described the greater part of 

 the posterior half of the skull, a fragment of the. maxilla, and the 

 main part of the ramus of the lower jaw. From the examination 

 of the foramina at the base of the skull, together with one or two 

 other characters, Owen was led to conclude that the remains were 

 those of a Marsupial, while from the characters of the temporal 

 fosste, occiput, and especially from the rudimentary condition of 

 the molars, together with the enormously large and cutting pre- 

 molars, which bore a considerable superficial resemblance to tho'^e 

 of the cat tribe, he was further led to the conclusion that the 

 form had been a carnivore, and " one of the fellest and most 

 destructive of predatory beasts."! His views of its affinities at 

 this time probably were that it had its nearest relatives in the 

 Dasyuridce, bearing apparently a somewhat similar relationship 

 to the existing carnivorous forms that the lion does to the dog. 

 At this time there was no evidence as to whether the lai-ge tooth 

 in the front of the jaw, indicated only by the socket, was a canine 



* On the Fossil Mammals of Australia. Part i. Description of a 

 mutilated Skull of a large Marsupial Carnivore {Thylacoleo carnifex, Owen) 

 from a calcareous conglomerate stratum, eighty miles S.W. of Melbourne, 

 Vic. Phil. Trans. Vol. 149, 1859. 



t Loc. at. p. 319. 



