CHAPTER XII 

 PROBOSCIDEA 



Suborder Pyrotheria 



THIS suborder was established by Ameghino to receive 

 the peculiar genus Pyrotherium and related forms. These 

 animals are of large size, massive build, with narrow 

 elongated skulls, in which the nasal opening is situated 

 far back, as in animals with a proboscis; with a tiny brain 

 case surrounded by cellular spaces; with the maxillae, 

 palatines, pterygoids and alispenoids developed downward, 

 so that the palatal plane makes a strong angle with the 

 basi-cranial plane; and with the occipital condyles high 

 up on the back of the skull. Then the first and second 

 upper incisors and the second lower incisors are developed 

 into enormous tushes with enamel on the anterior sides only. 

 The remaining incisors, the canines, upper premolar i, 

 and lower premolars I and 2 are wanting; the remaining 

 premolars and the molars being developed into great 

 quadrilateral grinders, each with two transverse crests. 

 The neck is short, the limbs massive and short, especially 

 the lower members of each limb, and the feet were probably 

 five- toed. 



The relationship of these forms has been the subject 

 of extended discussion: Ameghino seeing in this genus 

 the ancestors of the Probiscidea, and comparing them with 

 Palaeomastodon, Dinotherium and Barytherium, even finding 

 resemblances to Diprotodon; Gaudry concludes that they 

 are not proboscidians; and others have suggested that 

 they were specialized toxodonts. I have prepared the 

 following table of comparisons with Palaeomastodon, a 

 toxodont, and Diprotodon. 



