locality, Bainoceratops efremovi . This genus was based on a few dorsal (back) vertebrae that were stated to differ from those of Protoceratops. In 2006 North American paleontologists Peter Makovicky and Mark A. Norell suggested that Bainoceratops may be synonymous with Protoceratops as most of the traits used to separate the former from the latter have been reported from other ceratopsians including Protoceratops itself, and they are more likely to fall within the wide intraspecific variation range of the concurring P. andrewsi. The authors Brenda J. Chinnery and Jhon R. Horner in 2007 during their description of Cerasinops stated that Bainoceratops, along with other dubious genera, was determined to be either a variant or immature specimen of other genera. Based on this reasoning, they excluded Bainoceratops from their phylogenetic analysis. Eggs and nests As part of the Third Central Asiatic Expedition of 1923, Andrews and team discovered the holotype specimen of Oviraptor in association with some of the first known fossilized dinosaur eggs (nest AMNH 6508), in the Djadokhta Formation. Each egg was elongated and hard-shelled, and due to the proximity and high abundance of Protoceratops in the formation, these eggs were believed at the time to belong to this dinosaur. This resulted in the interpretation of the contemporary Oviraptor as an egg predatory animal, an interpretation also reflected in its generic name. In 1975, the Chinese paleontologist Zhao Zikui named the new oogenera Elongatoolithus and Macroolithus, including them in a new oofamily: the Elongatoolithidae. As the name implies, they represent elongated dinosaur eggs, including some of referred ones to Protoceratops. In 1994 the Russian paleontologist Konstantin E. Mikhailov named the new oogenus Protoceratopsidovum from the Barun Goyot and Djadokhta formations, with the type species P. sincerum and additional P. fluxuosum and P. minimum. This ootaxon was firmly stated as belonging to protoceratopsid dinosaurs since they were the predominant dinosaurs where the eggs were found and some skeletons of Protoceratops were found in close proximity to Protoceratopsidovum eggs. More specifically, Mikhailov stated that P. sincerum and P. minimum were laid by Protoceratops, and P. fluxuosum by Breviceratops. However, also during 1994, Norell and colleagues reported and briefly described a fossilized theropod embryo inside an egg (MPC-D 100/971) from the Djadokhta Formation. They identified this embryo as an oviraptorid dinosaur and the eggshell, upon close examination, turned out be that of elongatoolithid eggs and thereby the oofamily Elongatoolithidae was concluded to