A somite (or primitive segment in older texts) is a division of the body of an animal. In vertebrates this is mainly discernible in the embryo stage, in arthropods it's a characteristic of a hypothetical ancestor. In vertebrates In the developing vertebrate embryo, somites are masses of mesoderm distributed along the two sides of the neural tube and that will eventually become dermis (dermatome), skeletal muscle (myotome), and vertebrae (sclerotome). Because the sclerotome differentiates befor… (More on Somite)