part of part of develops from develops from right cardiac atrium fossa ovalis of heart SCTID:277719009 FMA:9246 Wikipedia:Fossa_ovalis_(heart) UBERON:0003369 Found in the right atrium of the heart, the fossa ovalis is an embryonic remnant of the foramen ovale, which normally closes shortly after birth. In a heart specimen of a neonate, the fossa ovalis is translucent, but later in life the membrane thickens. fossa ovalis oval fossa foramen ovale of heart anatomical surface region