58 AFFINITIES AND HABITS OF THYLACOLEO, 



or a terminal incisor, and though Owen inclined to regard it as a 

 canine, he admits the possibility of its being an incisor, in which 

 case he recognised that the affinities would be more with the 

 Diprotodonts, for he adds : — " If, however, this be really the 

 foremost tooth of the jaw it would be one of a pair of terminal 

 incisors according to the marsupial type exhibited by the llacro- 

 podidce and the Phalangistidce."* 



In 1866, through receiving further material from Australia, 

 Owenf was enabled to describe the greater part of the skull and 

 of the lower jaw, and to indicate fully the nature of the dentition. 

 It was now clearly shown that the large anterior teeth were 

 incisors which in Owen's opinion " proved the Thylacoleo to be 

 the carnivorous modification of the more common and character- 

 istic type of Australian Marsupials, having the incisors of the 

 lower jaw reduced to a pair of large, more or less procumbent 

 and approximate, conical teeth or * tusks.' "f Not only did the 

 additional evidence confirm him in his opinion that Thylacoleo 

 was a carnivore, but he considers that in this extinct form we 

 have " the simplest and most efiective dental machinery for pre- 

 datory life and carnivorous diet known in the Mammalian class. 

 It is the extreme modification, to this end, of the Diprotodont 

 type of Mar8upialia."§ Beyond admitting its affinities with the 

 Diprotodonts he does not seem to have regarded it as a near 

 relative of any of the existing groups. But from his statements 

 in the article on Palaeontology in the Encyclopa?dia Britannica, 

 8th Edition, 1859, he apparently regarded Thylacoleo as related 

 to Plagiaulax. 



In 1868, Flower read a paper before the Geological Society of 

 London — " On the Affinities and probable Habits of the Extinct 



* Loc. cit. p. 318. [See also a later paper, Vol. 174, Pt. ii. 1SS3, pp. 576- 

 577.— Ed.] 



+ On the Fossil Mammals of Australia. Part ii. Description of an 

 almost entire Skull of Thylacoleo carnifex, Owen, from a fresh-water 

 deposit. Darling Downs, Queensland. Phil. Trans. 1866, clvi. p. 73. 

 X Loc. cit. p. 80. § Loc. cit. p. 81. 



