Utah State University Eastern Price, Utah, United States
Abstract Body : We examined the macroscopic features on the remains of two nearly complete Mammuths columbi to identify etiopathologies of the skeleton. Modern-day proboscideans tend to suffer from arthritis under the classification of spondyloarthropathy more so than osteoarthritis. Spondyloarthropathy has not only been recorded in modern elephants but also in the fossil record of mastodons and mammoths. Various forms of spondyloarthropathy have been expressed in proboscideans, including ankylosing spondylitis, diffused idiopathic skeletal hypertosis (DISH), and Reiter’s syndrome. A common feature of all forms of spondyloarthropathy is the expression of disease in the axial skeletal joints, such as the spine and sacroiliac joints.
CEUM 897 (the Huntington Mammoth), was discovered on the Wasatch Plateau of Central Utah in 1988. It is a nearly complete and well-preserved specimen, missing only the smaller elements of the skeleton. CEUM 897 is estimated to be a 55-60 year old male based on tooth wear and pelvic morphology. Another mammoth, nicknamed Zed, was excavated from Pit 23 at Rancho La Brea in Los Angeles, California in 2006. As with CEUM 897, Zed is nearly complete, and estimated to be a 47-51 year old male. We examined the macroscopic anatomy, photographed, and 3D surface scanned pathologic elements of both specimens.
We found fusion in the axial skeleton of both individuals; however, those pathologies differ greatly from one another. CEUM 897 possesses three fused thoracic vertebrae with the gross appearance of unilateral dripping candle wax on the left side. This is consistent with the diagnosis of new bone production in the anterior longitudinal ligament. In the area of fusion, it's intervertebral spacing appears unaffected. The pathologies exhibited by CEUM 897 are consistent with early DISH. Zed has two regions of fusion within his vertebrae, seen in thoracic 15-16 as well as thoracic 17-lumbar 2. Despite the presence of two separate regions of fusion, they are neighboring. That supports a diagnosis of ankylosing spondylitis, where spinal fusion occurs without skip lesions. Unlike DISH, the intervertebral spacing is heavily affected by the formations of marginal syndesmophytes. Additionally, vertebrae that are not fused are very squared, which is also consistent with ankylosing spondylitis. Recognition of two forms of spondyloarthropathy in separate individuals of Mammuthus columbi helps place bone diseases that affect modern members of their clade (i.e., the endangered Elaphus maximus) into a broader evolutionary context.
