Wikipedia
Cairanoolithus is an oogenus of dinosaur egg which is found in Southwestern Europe. The eggs are large ( in diameter) and spherical. Their outer surface is either smooth, or covered with a subdued pattern of ridges interspersed with pits and grooves. Multiple fossil egg clutches are known but the nest structure is unclear.
The parent of Cairanoolithus is probably some kind of non- ornithopod ornithischian, possibly the nodosaurid Struthiosaurus.
The eggs were first named in 1994, when the two oospecies were classified in distinct oogenera as Cairanoolithus dughii and Dughioolithus roussetensis. They are now considered to belong in a single oogenus, possibly even a single oospecies. Though it has been classified as a megaloolithid, Cairanoolithus is usually placed in its own oofamily, Cairanoolithidae.