CHAPTER XIII 



HISTORY OF THE fLITOPTERNA AND fASTRAPOTHERIA 



Besides the four well-defined groups which make up the 

 tToxodontia (or jNotoungulata) there are two other extinct 

 orders of indigenous South American ungulates, which remain 

 to be considered. These did not have the exceptional develop- 

 ment of the auditory region of the skull which characterized 

 the fToxodontia. The best known and most important genera 

 of the fLitoptema are Usted in the following table : 



tLITOPTERNA. tLitopterns 



I. fMACHAUCHENID^. 



■[Macraixhenia, Plioc. and Plebt. ^ScaMbrinitherium, Parand. 

 ^Theosodon, Santa Cruz. fCramaiichenia, Patagonian. ^Pro- 

 theosodon, Deseado. 



II. PROTEROTHBRIID.E. 



^Epitherium, Monte Hennoso. ^Diadiaphorus, Santa Cruz and 

 Parand. ^ Proterotherium, do. ] ThocUherium,, Santa Cruz. 

 ^Dmiterotherium, Deseado. ^ Prothoatherium, do. 



III. DlDOLODID^. 



\Didolodus, Casa Mayor. ^ Lambdaconus, do. ] Notoprogonia, do. 

 ^ Proectocion, do., etc., etc. 



Only one of the families of this suborder survived into the 

 Pampean stage, where it was represented by a single genus, 

 ^Macrauchenia. Like all the other large Pampean mammals 

 of distinctly South American type, this was a grotesque crea- 

 ture, from the modern point of view. The genus was first dis- 

 covered by Darwin, who says of it : "At Port St. Julian, in 

 some red mud capping the gravel on the 90-foot plain, I foimd 

 half the skeleton of the Macrauchenia Patachonica, a remark- 

 able quadruped, full as large as a camel. It belongs to the 



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