also leptomeninges, odontocytes, and laryngeal cartilage (bone/cartilage from branchial arches) Dura connective tissue Mesoderm muscle mesoderm bone mesoderm CV structures, blood mesoderm lymphatics mesoderm urogenital structures mesoderm serous linings (peritoneum) mesoderm spleen mesoderm adrenal cortex mesoderm gut tube epithelium - lungs, liver, pancreas Endoderm Thymus endoderm (also starts as gut tube) Thyroid, parathyroid Endoderm