g THE CERATOPSIA 



originally used to include the Kirtland and Fruitland as well. Were we to identify without ques- 

 tion Trkeratop itself, its reference to the McDermott or Ojo Alamo as now restricted would be 

 expected, but all of the ceratopsian material from the Southwest other than the several recognizable 

 Pentaceratofs specimens is too fragmentary for certainty of generic reference. 



The Mongolian Protoceratofs from the Dja-doch-ta formation, has its nearest taxonomic equiv- 

 alent in Leftoceratofs of the Edmonton. Whether this one fact has correlation value without further 

 evidence is open to question. 



The geological sequence of the ceratopsian species is as follows: 



Judith River Formation 



Ceratofs montanus 



Monoclonius crassus 

 Monoclonius recurvicornis 

 Monoclonius sfhenocerus 



Belly River Formation 



Chasmosaurus belli 

 Chasmosaurus kaheni 

 Chasmosaurus brev'irostris 

 Monoclonius dawsoni 

 Monoclonius (Centrosaurus) afertus 

 Monoclonius (C) flexus 

 Monoclonius (C.) cutleri 

 Monoclonius (C.) nasicornus 

 Eoceratofs canadensis 

 Styracosaurus albertensis 



Two Medicine Formation 



Br achy ceratofs montanensis 

 Styracosaurus ovatus 



Edmonton Formation 



Anchiceratofs ornatus 

 Anchiceratofs longirostris 

 Arrhinoceratofs brachyofs 

 Leftoceratofs gracilis 



Fruitland and Kirtland Formation 



Pentaceratofs sternbergii 

 Pentaceratofs fenestratus 



Lance Formation 



Torosaurus gladius 

 T orosaurus latus 

 Triceratofs alticornis 

 Triceratofs brevicornus 

 Triceratofs calicornis 

 Triceratofs elatus 

 Triceratofs flabellatus 

 Triceratofs galeus 

 Triceratofs (Diceratofs) hatcheri 

 Triceratofs horridus 

 Triceratofs maximus 

 Triceratofs obtusus 

 Triceratofs frorsus 

 Triceratofs serratus 

 Triceratofs sulcatus 



Dja-doch-ta Formation, Mongolia 



Protoceratofs andrewsi 



