Fig 1.
The articulated right maxilla and jugal of Hualianceratops wucaiwanensis (IVPP V18641).
(A) photograph in lateral view, (B) photograph in medial view, (C) drawing in lateral view, (D) drawing in medial view. Abbreviations: afo, antorbital fossa; cp, caudomedial process of the jugal; dp, caudodorsal process of the jugal; j, jugal; jn, jugal node; ma, maxilla; or, orbit; po, postorbital; sq, squamosal.
Fig 2.
The articulated right maxilla and partial jugal of Hualianceratops wucaiwanensis (IVPP V18641), the broken rostral part of the elements in Fig 1.
(A) photograph in lateral view, (B) drawing in lateral view, (C) photograph in ventral view with inset of a tooth enlarged, (D) drawing in ventral view, (E) photograph in dorsal view, (F) drawing in dorsal view, (G) photograph in medial view, (H) drawing in medial view. Abbreviations: ma, maxilla; j, jugal.
Fig 3.
The articulated left partial jugal and quadratojugal of Hualianceratops wucaiwanensis (IVPP V18641).
(A) photograph in lateral view, (B) photograph in medial view, (C) drawing in lateral view; (D) drawing in medial view. Abbreviations: cp, caudomedial process of the jugal; dp, caudodorsal process of the jugal; qj, quadratojugal; q, quadrate; j, jugal.
Fig 4.
Comparisons of the infratemporal ramus of the jugal in basal ceratopsians.
Outline drawing of the holotype skull of Yinlong downsi showing the infratemporal ramus of the jugal (red) in lateral view (A) and ventral view (B), and the infratemporal ramus in basal ceratopsians in right lateral view (C-H) and ventral view (I-N). (C) Hualianceratops wucaiwanensis (IVPP V18641), (D) Yinlong downsi (IVPP V14530), (E) Hongshanosaurus houi (IVPP V12617), (F) Chaoyangsaurus youngi (IGCAGS V371), (G) Liaoceratops yanzigouensis (IVPP V12633), (H) Archaeoceratops oshimai (IVPP V11114). (I) Hualianceratops wucaiwanensis (IVPP V18641), (J) Yinlong downsi (IVPP V14530), (K) Hongshanosaurus houi (IVPP V12617), (L) Chaoyangsaurus youngi (IGCAGS V371), (M) Liaoceratops yanzigouensis (IVPP V12633), (N) Archaeoceratops oshimai (IVPP V11114). The arrows show the caudal process of the infratemporal ramus of the jugal. Abbreviations: j, jugal; qj, quadratojugal.
Fig 5.
Comparison of the quadrates in Hualianceratops wucaiwanensis and Yinlong downsi.
(A-F) right quadrate and quadratojugal of Hualianceratops wucaiwanensis. (A) photograph in lateral view, (B) photograph in caudal view, (C) photograph in rostral view, (D) drawing in lateral view, (E) drawing in caudal view, (F) drawing in rostral view. (G-I) left quadrate of Yinlong (IVPP V18637) flipped for comparison with the right side. (G) Photograph in lateral view, (H) photograph in caudal view, (I) photograph in rostral view. Abbreviations: gr, groove; q, quadrate; qj, quadratojugal; qj.a, articulation with the quadratojugal; qn, quadrate notch.
Fig 6.
The squamosal of Yinlong downsi (IVPP V18641).
(A) dorsal view, (B) ventral view, (C) left lateral view, (D) caudal view. Abbreviations: fo, fossa on the lateral surface; nd, nodes on the caudal margin; qp, stalked quadrate process.
Fig 7.
The mandible of Hualianceratops wucaiwanensis (IVPP V18641).
(A) photograph in lateral view, (B) drawing in lateral view, (C) photograph in ventral view, (D) drawing in ventral view. Abbreviations: an, angular; d, dentary; emf, external mandibular fenestra; imf, inner mandibular fenestra; lsp, left splenial; pra, prearticular; pd, predentary; rsp, right splenial; sa, surangular.
Fig 8.
Comparison of the mandible in basal ceratopsians in right lateral view.
(A) Hualianceratops wucaiwanensis (IVPP V18641), (B) Hongshanosaurus houi (IVPP V12617), (C) Yinlong downsi (IVPP V14530), (D) Archaeoceratops oshimai (IVPP V11114), (E) Chaoyangsaurus youngi (IGCAGS V371), (F) Liaoceratops yanzigouensis (IVPP V12633). Abbreviations: an, angular; co, coronoid; d, dentary; pd, predentary; sa, surangular.
Fig 9.
Postcranial material of Hualianceratops wucaiwanensis (IVPP V18641).
(A-B) two fused sacral vertebrates, cranial end is to the left. (A) ventral view, (B) dorsal view. (C) partial hind limb and left pes of Hualianceratops wucaiwanensis. Abbreviations: rf, right fibula; rt, right tibia; lf, left fibula; mt.I-II, metatarsal I-II; pII-IV, pes digits II-IV.
Table 1.
Skull measurements of Hualianceratops (IVPP 18641) and Yinlong downsi [IVPP 14530 (holotype), IVPP 18637], in millimeters.
Fig 10.
Strict consensus tree of 216 most parsimonious trees produced by analysing a data matrix of 37 taxa and 210 characters.
Bremer support (values above 1) is shown below and to the left of nodes, and bootstrap values are labeled to the left and above the nodes (values above 50%).
Fig 11.
Ghost lineages implied by this phylogenetic analysis.
Ghost lineages (gray lines) implied by the stratigraphic distributions of taxa and the most parsimonious trees. Thick black lines indicate single occurrences, their length reflects uncertainty in dating. One of the phylogenies implying the fewest lineages is shown. Geochronology from [41].