The ornamentation is compactituberculate, i.e. the eggshell is covered with dome-like nodes formed by the tops of the shell units.

[3][5] The high density of pores on the eggshell surface suggests that these eggs were laid in a humid environment.

[3] At the Mercedes Formation, Sphaerovum-like eggs were found in large, closely packed groups indicating that they were buried in a shallow pit.

[4] The holotype specimen of Sphaerovum is heavily silicified, making the eggshell structure unrecognizable and assignment to any oofamily difficult.

Also, some eggshell fragments tentatively assigned to Sphaerovum were found loosely associated with the remains of a Saltasaurid titanosaur at the Guichón Formation in Uruguay.