50 THE DESEADO FORMATION OF PATAGONIA 



RESTORATION 



In order to get a comparison of what is known of this 

 form with Theosodon I have outlined a restoration of the 

 animal as a whole, realizing that some essential parts are 

 lacking, but the general proportions can hardly vary greatly 

 from those given. It appears, first, that this form has 

 an unusually short back. Though the limbs and lower 

 jaw are | the length of those of Theosodon garrettorum, 

 the vertebrae are \ as long. I have assumed that the 

 number of vertebrae would prove to be the same as in 

 Theosodon. While the limb bones are f as long as in the 

 Theosodon, they are relatively half again as heavy and with 

 the processes much more developed. The greatest differ- 

 ence is found in the tarsus which is only ^ as long as that 

 of Theosodon, though relatively as heavy, and the foot 

 was carried in a nearly plantigrade position the heel raised 

 but a little from the ground, though the anticular ends of 

 the metatarsals and the phalanges indicate that there was 

 a considerable freedom of movement of the various ele- 

 ments. The form seems to be fairly close to the ancestral 

 types such as Lambdaconus of the Casamayor, the limbs 

 of which, however, are entirely unknown, but I should 

 expect that when found these earlier forms would prove 

 to be approximately plantigrade. 



Coniopternium Ameghino 



Coniopternium Amegh., 1895 Bol. Inst. Geog. Argen., t. 15, p. 632. 

 Coniopternium Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 453. 



The genus is based on a calcaneum and astragulus of 

 the macrauchenid type, but of unusually large size. The 

 real generic characters are not evident in the description, 

 but the presence of these bones, and of three cervical verte- 

 brae, which w r e also found, indicating a macrauchenid of 

 about the same size, are evidence that a form larger than 

 the Santa Cruz representatives will turn up in the Deseado 

 beds, for which this name may be reserved. The material 

 is described under the specific name C. andinum. 



