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Description
This cladogram is speculative, but it is mostly in line with scientific studies mixed in with my own opinion; no actual phylogenetic analysis was undertaken. Feel free to comment or suggest changes, but be aware that I may reject or modify your suggestions.

Definitions for clade names:

Ceratopsia - Ceratops montanus, Triceratops horridus <- Pachycephalosaurus wyomingensis
Chaoyangsauridae - Chaoyangsaurus youngi <- Psittacosaurus mongoliensis, Triceratops horridus
Neoceratopsia - Triceratops horridus <- Chaoyangsaurus youngi, Psittacosaurus mongoliensis
Archaeoceratopsidae - Archaeoceratops oshimai <- Triceratops horridus
Euceratopsia - Leptoceratops gracilis + Protoceratops andrewsi + Triceratops horridus
Leptoceratopsidae - Leptoceratops gracilis <- Protoceratops andrewsi, Triceratops horridus
Leptoceratopsinae - Leptoceratops gracilis <- Montanoceratops cerorhynchos
Coronosauria - Coronosaurus brinkmani <- Leptoceratops gracilis
Protoceratopsidae - Protoceratops andrewsi <- Ceratops montanus, Leptoceratops gracilis, Triceratops horridus
Ceratopsoidea (= Ceratopsomorpha) - Ceratops montanus, Triceratops horridus <- Protoceratops andrewsi
Ceratopsidae - see here

Please note that the above names and/or definitions are not meant to constitute nomenclatural or definitional acts.

Sources for cladogram include but are not limited to:

Arbour & Evans (2019). "A new leptoceratopsid dinosaur from Maastrichtian-aged deposits of the Sustut Basin, northern British Columbia, Canada"
Farke et al. (2014). "A Ceratopsian Dinosaur from the Lower Cretaceous of Western North America, and the Biogeography of Neoceratopsia"
Han et al. (2018). "Postcranial anatomy of Yinlong downsi (Dinosauria: Ceratopsia) from the Upper Jurassic Shishugou Formation of China and the phylogeny of basal ornithischians"
Napoli et al. (2019). " Psittacosaurus amitabha, a new species of ceratopsian dinosaur from the Ondai Sayr locality, central Mongolia"
Sereno (2010). "Taxonomy, cranial morphology, and relationships of parrot-beaked dinosaurs (Ceratopsia: Psittacosaurus)"

Description
This cladogram is speculative, but it is mostly in line with scientific studies mixed in with my own opinion; no actual phylogenetic analysis was undertaken. Feel free to comment or suggest changes, but be aware that I may reject or modify your suggestions.

Definitions for clade names:

Ceratopsia - Ceratops montanus, Triceratops horridus <- Pachycephalosaurus wyomingensis
Chaoyangsauridae - Chaoyangsaurus youngi <- Psittacosaurus mongoliensis, Triceratops horridus
Neoceratopsia - Triceratops horridus <- Chaoyangsaurus youngi, Psittacosaurus mongoliensis
Archaeoceratopsidae - Archaeoceratops oshimai <- Triceratops horridus
Euceratopsia - Leptoceratops gracilis + Protoceratops andrewsi + Triceratops horridus
Leptoceratopsidae - Leptoceratops gracilis <- Protoceratops andrewsi, Triceratops horridus
Leptoceratopsinae - Leptoceratops gracilis <- Montanoceratops cerorhynchos
Coronosauria - Coronosaurus brinkmani <- Leptoceratops gracilis
Protoceratopsidae - Protoceratops andrewsi <- Ceratops montanus, Leptoceratops gracilis, Triceratops horridus
Ceratopsoidea (= Ceratopsomorpha) - Ceratops montanus, Triceratops horridus <- Protoceratops andrewsi
Ceratopsidae - see here

Please note that the above names and/or definitions are not meant to constitute nomenclatural or definitional acts.

Sources for cladogram include but are not limited to:

Arbour & Evans (2019). "A new leptoceratopsid dinosaur from Maastrichtian-aged deposits of the Sustut Basin, northern British Columbia, Canada"
Farke et al. (2014). "A Ceratopsian Dinosaur from the Lower Cretaceous of Western North America, and the Biogeography of Neoceratopsia"
Han et al. (2018). "Postcranial anatomy of Yinlong downsi (Dinosauria: Ceratopsia) from the Upper Jurassic Shishugou Formation of China and the phylogeny of basal ornithischians"
Napoli et al. (2019). " Psittacosaurus amitabha, a new species of ceratopsian dinosaur from the Ondai Sayr locality, central Mongolia"
Sereno (2010). "Taxonomy, cranial morphology, and relationships of parrot-beaked dinosaurs (Ceratopsia: Psittacosaurus)"