An ellipsoidal dome is a dome (also see geodesic dome), which has a bottom cross-section which is a circle, but has a cupola whose curve is an ellipse.
A prolate ellipsoidal dome is derived by rotating an ellipse around the long axis of the ellipse; an oblate ellipsoidal dome is derived by rotating an ellipse around the short axis of the ellipse.
[2] Of small note, in reflecting telescopes the mirror is usually elliptical, so has the form of a "hollow" ellipsoidal dome.
The Jameh Mosque of Yazd has an ellipsoidal dome.
[3] This article related to an architectural style is a stub.