FOSSIL VERTEBRATES FROM SAN PEDRO VALLEY—GAZIN 479 
and lying in a horizontal position resting on the lower jaws, but the top portion 
of the skull was crushed and eroded and the tips of the tusks reaching to the 
same level were broken. This damage had evidently been done while the skull 
yet lay partly buried in wet mud. Also the left fore leg of this animal was 
found in nearly normal position relative to the skull, but with the toes directed 
downward, reaching a level in the clay 2 feet below it. This position indicates 
that the animal came to his death by being hopelessly bogged. The position 
and arrangement of the other bones as found suggested that they had been 
moved about by being more or less trampled and disturbed by contemporary 
animals who were so fortunate as to escape being engulfed in the soft and sticky 
mud. A foot of each of the other two mastodons collected was found in a like 
position, giving additional evidence of boggy conditions. The carapace of 
Glyptotherium showed evidence of trampling. The top had been caved in before 
being completely covered and may have been thus crushed by the foot of a 
Stegomastodon arizonae while being partly buried. 
SAN PEDRO VALLEY FAUNAS 
A comparative list of the faunas from the two localities is given 
below: 
BENSON CurTIS RANCH 
AMPHIBIA : 
Amphibian remains 
REPTILIA : REPTILIA : 
Testudinata Testudinata 
Kinosternidae Testudinidae 
Kinosternon arizonense Testudo sp. 
Gilmore 
Squamata Squamata 
Iguanidae Colubridae 
Crotaphytus? sp. Colubrid sp. 
AVES: AVES: 
Colymbiformes 
Colymbidae 
Colymbus sp. 
Anseriformes 
Anatidae 
Querquedula sp. 
Dendrocygna eversa 
Wetmore 
Anabernicula minuscula 
(Wetmore) 
Anatid (indet.) 
Galliformes Galliformes 
Meleagridae 
Agriocharis sp. 
Phasianidae Phasianidae 
Colinus sp. Odontophorid (indet. ) 
Gruiformes 
Rallidae 
Gallinula sp. 
