This is a closer look at
the articulating surface/socket on the same right proximal scapula
(shoulder blade) of a large camel seen in the previous image;
it's from the Late Miocene Dove Spring Formation of the Ricardo
Group, El Paso Mountains, Kern County, California; in actual
size, the circular articulating surface is 7 and a half centimeters
in diameter. Identified by Dr. Hugh Wagner, San Diego Natural
History Museum and Dr. Robert Emry of the National Museum of
Natural History, Smithsonian Institution. According to Dr. Robert
Emry, the socket is called the genoid fossa, which articulates
with the head of the humerus (upper arm bone) at the shoulder
joint. |