44. THE DESEADO FORMATION OF PATAGONIA 
MEASUREMENTS 
Lower dentition, total length 114 mm. 
incisors, length 20 mm. 
canine, length 8 mm. 
premolar 2 to 4 35 mm. 
molar 1 to 3 42 mm. 
Mandible, total length 188 mm. 
height under molar 1 24 mm. 
height to top of coronoid 95 mm. 
The dorsal vertebrae have short, wide, and somewhat 
depressed centra (in this individual the epiphyses are 
free, though this is the only indication of youth). The 
lower rib facets are small, that on the posterior margin of 
the centrum being a mere streak, while the one on the 
anterior margin is narrow. ‘The upper rib facet is a rounded 
convex surface on the end of a short stout transverse proc- 
ess. The prezygapophyses are convex surfaces, wide 
transversely, but narrow in the anteroposterior direction, 
while the postzygapophyses are correspondingly narrow 
concave facets under the rear of the spines. ‘The spines 
are thin and high, and the neural canal is nearly circular in 
section. 
The lumbar vertebrae have laterally compressed, deep 
centra, with very long transverse processes, shorting spines, 
and zygapophyses of the subcylindrical interlocking type. 
In all their features the vertebrae resemble those of Theo- 
sodon, being nearly as highly specialized and in the same 
manner. 
MEASUREMENTS OF TYPICAL VERTEBRAE 
Dorsal vertebra No. 7, length 23 mm. 
width of centrum ’ 22 mm 
Dorsal vertebra No. 9, length 28 mm. 
Lumbar vertebra No. 2, length 29 mm 
Lumbar vertebra No. 2, width of centrum 24 mm. 
Lumbar vertebra No. 2, width across transverse processes 160 mm. 
The femur is short and very stocky. The rounded head 
is carried on a short neck, and does not rise nearly as high 
as the greater trochanter, the sulcus for the round liga- 
