The Allantois and Urachus: Histological Study Using Human Embryo and Fetuses.
Xuelai LiuXianghui XieZhe Wu JinHuan WangYanbiao SongPeng ZhaoLong LiPublished in: Fetal and pediatric pathology (2021)
The urachus forms from the distal end of the allantois and develops into a closed fibrous cord between the base of the urinary bladder and the umbilicus. The urogenital sinus forms from the proximal end of the allantois.