Sankofa may represent the fossilized eggs of a transitional species between non-avian theropods and birds.

[1] Sankofa pyrenaica is known solely from the Aren Formation, in the southern Pyrenees of Catalonia, Spain, dating from the Upper Campanian to Lower Maastrichtian.

The eggshell has a smooth surface with no trace of ornamentation, and highly variable pore density.

A morphometric analysis by López-Martínez and Vicens in 2012 found that it was an intermediate shape between avian and non-avian theropods, and also very similar to an enantiornithine egg from the Bajo de la Carpa Formation in Argentina, though their microstructures are quite different.

Cladistic analysis found Sankofa to be in a polytomy with Protoceratopsidovum, Troodon eggs, and birds.