This rather stout bone is one of our best-preserved bison humeri. This is the left humerus, shown above in anterior view.
The distal end, at the elbow joint, is on the left, while the proximal end (shoulder joint) is on the right. Bison have a large knob of bone called the lateral tuberosity which is broken off of this specimen; it should be at located at the lower right. The darker lines and patches are sediment that has not yet been removed.
Below is the posterior view:
Again, proximal is on the right. The large humoral head that articulates with the scapula to form the shoulder joint is visible on the right. The large notch on the distal end (on the left) is the olecranon fossa. This accommodates the olecranon process of the ulna (the point of the elbow) when the front leg is extended.
Here are the lateral and medial views:
This humerus was found at the West Dam of Diamond Valley Lake. West Dam deposits are older than those at the East Dam, and contain both Bison antiquus and Bison latifrons; it’s not clear which species is represented here.