Line diagram of the holotype specimen (ZPAL MgD-I/117) of the protoceratopsid Breviceratops kozlowskii. Based on Maryańska & Osmólska 1975,[1] and Czepiński 2019.[2] References ↑ (1975). "Protoceratopsidae (Dinosauria) of Asia". Palaeontologia Polonica 33: 134−143. Archived from the original on 2018-09-21. Retrieved on 2021-07-25. ↑ (2019). "Ontogeny and variation of a protoceratopsid dinosaur Bagaceratops rozhdestvenskyi from the Late Cretaceous of the Gobi Desert". Historical Biology: 1−28. DOI:10.1080/08912963.2019.1593404. Archived from the original on 2021-07-08. Retrieved on 2021-07-25.