Ischium Ischium The ischium () forms the lower and back part of the hip bone ("os coxae"). Situated below the ilium and behind the pubis, it is one of these three bones whose fusion creates the hip. The superior portion of this bone forms approximately one third of the acetabulum. The ischium is made up of three parts–the body, the superior ramus and the inferior ramus. The body contains a prominent spine, which serves as the origin for the superior gemellus muscle. The indentation inferior to the spine is the lesser sciatic notch. Continuing down the posterior side, the ischial tuberosity
Petrous part of the temporal bone highly degraded, and contaminated by DNA from soil microbes. In 2015 it was found, surprisingly, that the petrous bone has remarkably high preservation of DNA. A 2017 study comparing DNA from different skeletal sites concluded that "The inner part of petrous bones and the cementum layer in teeth roots are currently recognized as the best substrates for (ancient DNA) research...Both substrates display significantly higher endogenous DNA content (average of 16.4% and 40.0% for teeth and petrous bones, respectively) than parietal skull bone (average of 2.2%)." Consequently, petrous bones are now the most widely-used skeletal site for the study of ancient