What is the oogenus name for the largest known dinosaur eggs?

The oogenus name for the largest known dinosaur eggs is Macroelongatoolithus.

An oogenus is a classification used for fossil eggs when scientists cannot confidently match them to a particular dinosaur species. Macroelongatoolithus eggs are exceptionally long and large, with the biggest specimens exceeding 60 centimetres in length. They are usually about three times longer than they are wide.

These eggs were once linked to large tyrannosaurs because of their size, but shell structure, egg shape and later discoveries point instead toward giant caenagnathid oviraptorosaurs. The 2017 description of Beibeilong, including an embryo nicknamed “Baby Louie,” provided especially important evidence because the embryo was associated with Macroelongatoolithus eggs.

The eggs have been found in Asia and North America, showing that these giant oviraptorosaurs had a broad geographic range. Their scientific history is complicated because several egg species and even egg genera have since been treated as synonyms, but Macroelongatoolithus remains the recognized oogenus for this giant egg type.