In planetary geology, a tholus (pl. tholi) is a small domical mountain or hill.

"THOLUS"
"THOLUS"
"THOLUS"
[Absurdities in modern medical terminology.]
Volcanism on Mars
Rahway Valles
Anaglyph of East Mareotis Tholus
Cannibalism in the Madagascan dinosaur Majungatholus atopus
Discovery of a flank caldera and very young glacial activity at Hecates Tholus, Mars
Explosive volcanism on Hecates Tholus, Mars: Investigation of eruption conditions
The vertebral column of Majungatholus atopus (Theropoda: Abelisauridae) from the Late Cretaceous of Madagascar
Valleys on Hecates Tholus, Mars: origin by basal melting of summit snowpack
Erosion by flowing Martian lava: New insights for Hecates Tholus from Mars Express and MER data