150 CARNIVORES. 
THE PRIMITIVE CARNIVORES. 
No account of the Carnivores would be complete without some reference, 
however brief, to a number of peculiar species occurring in the Miocene and 
Eocene formations of Europe and America, which differ so remarkably from all 
living terrestrial representatives of the order, as to render it imperative to refer 
them to a totally distinct group. These extinct primitive, or, as they are techni- 
cally called, Creodont Carnivores, differ from modern land Carnivores in the 
absence of a distinct flesh-tooth in either jaw; all the molar teeth of each jaw 
being constructed on the same plan, and the whole of those in the lower jaw being 
frequently like the single flesh-tooth of other Carnivores. As a rule, the crowns 
of the upper molar teeth are triangular in form, and of the type noticed on p. 340 
of the first volume. And whereas in all existing Carnivores the two bones in the 
upper row of the wrist, technically known as the seaphoid and lunar, are com- 
pletely welded together, in nearly all the Creodonts they remain quite distinct. 
These and other characters indicate that these primitive Carnivores are a much 
more generalised group than the modern land Carnivores, of which they may have 
been the direct ancestors. Moreover, the teeth of many of these extinct forms are 
so like those of the carnivorous Marsupials (although agreeing generally in number 
with the modern carnivorous type, as exemplified by some of the dogs), that there 
is considerable probability that in these animals we have a direct connecting link 
between the Marsupials and the existing land Carnivores. The best known repre- 
sentatives of this group in Europe have been described under the names of Hycano- 
don and Pterodon ; and while some of the species were no larger than a fox, 
others attained dimensions nearly or fully equal to those of a brown bear. There 
is little doubt that from some of these primitive Carnivores—and more especially 
the North-American forms known as Miacis—the majority of the existing land 
Carnivores are descended. It is noteworthy that an American and European genus 
known as Palwonictis shows a remarkable-gradation in the structure of its teeth 
towards the cats, although it is rather difficult to believe that the cats are directly 
derived from this primitive form. 
