200 Professor Marsh’s Monograph of the Dinocerata. 
GENEALOGY OF UNGULATES. 
“From this primitive type of mammal, a special line appar- 
ently led off through the Triassic and Jurassic to the Cretaceous, 
where it formed a well-marked group, which may be called 
the siesonelonipene the probable ancestors of. all succeeding 
these have continued to the present time, the survivors being 
the ers the Artiodactyla, and the Perissodactyla. 
38. 
| Recent. Pron” Hyrae. Art. Pertss. | 
-| Quaternary. \ | 
Pili : Mastodon 
| sot ss — Dinothertum | 
| 5] Miocene. | ‘ 
| x “Bre tothertum 
| ee | a 
B i f ‘clacodon. ae 
Kocene. : \ 
‘ . 
Amblydactyla} sHolodactyla : 
| Cret es | 
retaceous. 
/ 
6 Protungulata ) 
Jurassic, 
Triassic. 
ee a lee 
Permian. fo co Lone tides : m8 
FIGURE 38. Diageo to illustrate the senanlags of Ungulate Mammals. 
“Another order, also, which may be termed the Amblydac 
tyla, passed off apparently from the main ungulate stem in ” 
minate yphodon, in ‘te lower Eocene, and the other, 
r onaniel ‘es the Dinocerata here hehe, came to an en 
in the middle Eocene 
