[1] Like other types of dinosaur eggs, the shell of Guegoolithus is made up of tightly packed crystalline units.

[2] The surface of the eggshell exhibits sagenotuberculate ornamentation (nodes and ridges forming a net-like pattern, with pits and grooves in between[4]).

[1] Guegoolithus was first discovered in 2000 by Spanish paleontologists Olga Amo-Sanjuán, José Ignacio Canudo, and Gloria Cuenca-Bescós, though it was described as an oospecies of Macroolithus.

[1] In 2016, Moreno-Azanza and several of his colleagues reported the discovery of a new fossil site in La Rioja, Spain, which included eggs assigned to Guegoolithus.

[1] Styracosterns (a clade of ornithopods that includes hadrosaurs and their close relatives) are, like G. turolensis, incredibly common in the lower Cretaceous of Spain.

The eggshell structure is apparently designed to be easily broken from the inside, indicating that these dinosaurs were altricial.