The first somites appear in the anterior portion of the trunk, and new somites “bud off” from the rostral end of the paraxial mesoderm at regular intervals (Figures 14.2C,D and 14.3). Somite formation begins as paraxial mesoderm cells become organized into whorls of cells called somitomeres.

What comes from paraxial mesoderm?

The paraxial mesoderm gives rise to the axial skeleton. The lateral plate mesoderm gives rise to the appendicular skeleton.

What are 3 layers of somites?

The mesoderm is the middle layer of the three germ layers that develop during gastrulation in the very early development of the embryo of most animals. The outer layer is the ectoderm, and the inner layer is the endoderm. The mesoderm forms mesenchyme, mesothelium, non-epithelial blood cells and coelomocytes.