part_of part of part of develops from develops from ends during starts during mesoderm presomitic mesoderm somite Any of the approximately 45 bilaterally paired blocks of mesoderm cells, lying on either side of the notochord and neural tube, and forming sequentially starting at the head during development of the embryo. Together they give rise to the axial skeleton (from the sclerotome), associated musculature (from the myotome), and dermis (from the dermatome). somitic mesoderm UBERON:0002329 somites XAO:0000058 xenopus_anatomy tissue muscular system NF stage 17 NF stage 47