244 



NOTOUNGULATA 



ORDER VIII 



3.1.4.3. 



Family 2. Albertogaudryidae Ameghino. 



Upper molars broader than long, slightly quadrangular, with short 



protoloph and a detached inner cusp. Lower premolars and molars consisting of 

 two crescents and a detached inner cusp. Incisors not well developed, upper canines 

 triangular. Premolars simpler than molars. Astragalus with a short neck. 



The members of this family, which are ancestral to the next to be 

 considered, attained the size of a tapir, and were among the largest of all 

 South American Eocene mammals. 



Alhertogaiidrija, Ruetimeyeria Ameghino. Upper molars rounded. Eocene ; 

 Notostylops beds. 



Scabellia Ameghino. Upper molars quadrangular. Eocene; Noto- 

 stylops beds. 



3.1.3-2.3. 



Family 3. Astrapotheriidae Ameghino. 

 Incisors small, especially the upper ones, which are cleft and have 



0.1. jj- 1 . o. 



two lobes. Canines developed as powerful, triangular tusks, whose tips close against 

 each other. Premolars are simpler and smaller than the molars and are fewer in 

 number. Upper molars are longer than wide and consist of a straight ectoloph, 

 an oblique protoloph and a short straight metaloph, also having a parastyle and 

 crest. M^ vdthout metaloph. Lower molars consist of two elongated crescents and 



Fig. 330. 



Astrapotherium miuinum Ameghino. Upper Miocene (Santa Cruz beds), Patagonia. A, Upper canine. 

 -B, Lower canine, 1/4. C, Upper third premolar to third molar. D, Lower fourth premolar to tliird molar, 

 1/3. (After Amegliino.) 



an inner cusp which is sometimes fused with the anterior end of the second crescent. 

 3fanus and pes pentadacfyl. Astragalus flat and with very short neck. 



These large ungulates, with dentition simulating that of rhinoceroses, 



