Megaloolithidae Temporal range: 171.6–48.6 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Egg fossil classification
Basic shell type:	†Dinosauroid-spherulitic
Oofamily:	†Megaloolithidae Zhao, 1979
Oogenera
Megaloolithus Pseudomegaloolithus

Megaloolithidae is an oofamily of fossil egg of the Dinosauroid-spherulitic morphotype. They probably are the eggs of sauropods.^[1]

Paleopathology

Multilayered shell

Megaloolithid eggs with multiple layers of eggshell have been preserved in the fossil record.^[2] Multilayered fossil eggs resemble those of modern forms in sometimes having incomplete extra layers and pore canals that don't properly align.^[3] The misalignment of the pore canals can prevent oxygen from getting to the embryo and cause it to suffocate.^[2] The term ovum in ovo has been used for multilayered dinosaur eggs although this is inaccurate use of the term.^[4] The greater abundance may indicate that these eggs were more prone to such pathologies, but are most likely due to a larger sample size of them.^[5] Megaloolithid eggs with a discretispherulitic morphotype account for the majority of dinosaur eggs preserved with this deformity.^[3]