fossa ovalis

https://doi.org/10.1351/goldbook.10740

Oval depression in the heart, on the lower part of the septum of the right atrium.

Note: The fossa ovalis is a remnant of the foramen ovale.

Source:
PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 758 (https://doi.org/10.1515/pac-2015-1202)