Fig 1.
Holotype of Ischioceratops zhuchengensis (ZCDM V0016) in right lateral view.
Photograph (A), drawing (B) and reconstruction of holotype individual (C). Abbreviations: cv, caudal vertebrae; lil, left ilium; ot, ossified tendons; rfem, right femur; rfib, right fibula; ril, right ilium; ris, right ischium; rtib, right tibia.
Fig 2.
Holotype of Ischioceratops zhuchengensis (ZCDM V0016) in dorsal view.
Photograph (left, scale bar equals 8 cm) and drawing (right). Abbreviations: cv, caudal vertebrae; lis, left ischium; ot, ossified tendons; pris, pit on right ischium; rfem, right femur; ril, right ilium; ris, right ischium; sa, sacral; sr, sacral rib.
Fig 3.
Caudal vertebrae of holotype of Ischioceratops zhuchengensis (ZCDM V0016) in right lateral view.
Caudals 2–11 (A), caudals 10–15 (B), caudals 1–2 (C). Abbreviations: ch, chevron; cv, caudal vertebrae; ns, neural spine; poz, postzygapophysis; prez, prezygapophysis; ril, right ilium; sa, sacrals; tp, transverse process.
Fig 4.
Ossified tendons of holotype of Ischioceratops zhuchengensis (ZCDM V0016), indicated by white arrows.
Abbreviations: li, left ilium; ot, ossified tendons; ri, right ilium; sa, sacral vertebrae.
Fig 5.
Pelvic girdle of holotype of Ischioceratops zhuchengensis (ZCDM V0016).
Left ilium in lateral view (A), right ilium in lateral view (B), and both ilia in dorsal view (C). Abbreviations: isped, ischiadic peduncle; ot, ossified tendons; pop, postacetabular process; pped, pubic peduncle; prp, preacetabular process; sa, sacral vertebra; sr, sacral rib.
Fig 6.
Ornithischian left ilia in lateral view.
All figures are just outlines, similar but not identical to the original image. All figures are for illustrative purposes only. Outlines are not to scale. A1, Heterodontosaurus tucki, outlined from [45]; A2, Othnielia rex, from [46]; A3, Hypsilophidon foxii, outlined from [34]; A4, Hexinlusaurus multidens, based on ZDMT 6001, outlined from [47]; A5 Agilisaurus louderbacki, based on ZDMT 6011, outlined from [47]; A6, Jeholosaurus shangyuanensis, based on IVPP V15939, outlined from [20]; B1, Tenontosaurus tilleti outlined from [48]; B2, Dryosaurus altus, based on HNM dy II, outlined from [49]; B3, Camptosaurus dispar, outlined from [50]; B4, Iguanodon atherfieldensis, outlined from [50], 1990; B5, Ouranosaurus nigeriensis, outlined from [50], 1990; C1, Gryposaurus incurvimanus, outlined from [51]; C2, Parasaurolophus cyrtocristatus, based on FMNH P27393, outlined from [52]; C3, Corythosaurus casuarius, outlined from [53]; C4, Gilmoreosaurus mongoliensis, based on AMNH 6551, outlined from [52]; C5, Brachylophosaurus canadensis, based on MOR794, outlined from [54]; C6, Edmontosaurus regalis, based on ROM 5167, outlined from [51]; C7, Saurolophus osborni, based on AMNH 5220, outlined from [51]; C8, Maiasaura peeblesorum, based on MOR unnumbered, outlined from [54]; C9, Kritosaurus navajovius, based on TMM 42309–2, outlined from [54]; D1, Homocephale calathocercos, outlined from [21]; E1, Yinlong downsi, based on IVPP V18637; E2, Psittacosaurus neimongoliensis, based on IVPP 12-0888-2, outlined from [55]; E3, Archaeoceratops oshimai, based on IVPP V11114, outlined from [24]; E4, Auroraceratops rugosus, outlined from [29]; E5, Protoceratops andrewsi, outlined from [6]; E6, Leptoceratops gracillis, based on NMC 8889, outlined from [56]; E7, Montanoceratops cerorhynchus, based on AMNH 6466, outlined from [28]; F1, Centrosaurus, outlined from [57]; F2, Chasmosaurus belli, outlined from [58]; F3, Triceratops horridus, based on YPM 1821, outlined from [59]; F4, Styracosaurus albertensis, based on AMNH 5372, outlined from [60]; upper: Ischioceratops zhuchengensis, based on ZCDM V0016.
Fig 7.
Ischia of holotype of Ischioceratops zhuchengensis (ZCDM V0016).
Left ischium in lateral view (A); right ischium in lateral view (B); close-up of pit on the right ischium (C). Abbreviations: cv, caudal vertebrae; isf, ischiadic foot; obp, obturator process; plis, pit on left ischium; pris, pit on right ischium; ril, right ilium.
Fig 8.
Ornithischian left ischia in lateral view.
All figures are just outlines, similar but not identical to the original image. All figures are for illustrative purposes only. Outlines are not to scale. A1, Heterodontosaurus tucki, outlined from [45]; A2, Othnielia rex, outlined from [46]; A3, Hypsilophodon foxii, outlined from [34]; A4, Hexinlusaurus multidens, based on ZDM 6001, outlined from [47]; A5 Agilisaurus louderbacki, based on ZDMT 6011, outlined from [47]; B1, Tenontosaurus tilleti, outlined from [48]; B2, Dryosaurus altus, outlined from [49]; B3, Camptosaurus dispar, outlined from [50]; B4, Iguanodon atherfieldensis, outlined from [50]; B5, Ouranosaurus nigeriensis, outlined from [50]; C1, Gryposaurus incurvimanus, outlined from [51]; C2, Parasaurolophus walkeri, based on FMNH P27393, outlined from [52]; C3, Corythosaurus casuarius, outlined from [53]; C4, Gilmoreosaurus mongoliensis based on AMNH 6551, outlined from [52]; C5, Edmontosaurus regalis ROM 5167, outlined from [54]; C6, Shantungosaurus giganteus, outlined from [62]; D1, Homocephale calathocercos, outlined from [21]; E1, Yinlong downsi, based on IVPP V18679; E2, Psittacosaurus neimongoliensis, based on IVPP 12-0888-2, outlined from [55]; E3, Archaeoceratops oshimai, based on IVPP V11114, outlined from [24]; E4, Auroraceratops rugosus, outlined from [29]; E5, Protoceratops andrewsi, outlined from [4]; E6, Leptoceratops gracillis, based on NMC 8889, outlined from [56]; E7, Montanoceratops cerorhynchus, based on AMNH 6466, outlined from [42]; E8, Ischioceratops zhuchengensis, right and left ilium and ischium, based on ZCDM V0016; F1, Centrosaurus apertus, outlined from [57]; F2, Chasmosaurus belli, outlined from, [58]; F3, Triceratops horridus, based on YPM 1821, outlined from [59]; F4, Styracosaurus albertensis, based on AMNH 5372, outlined from [60].
Table 1.
Measurements of the caudal vertebrae of the holotype specimen of Ischioceratops zhuchengensis (ZCDM V0016).
Fig 9.
Right femur of holotype of Ischioceratops zhuchengensis (ZCDM V0016).
Right femur in lateral (A), medial (B) and anterior views (C). Abbreviations: atr, lesser trochanter; ftr, fourth trochanter; gtr, greater trochanter; ot, ossified tendons; ril, right ilium; sa, sacrals.
Fig 10.
Ornithischian left femur in lateral view.
All figures are just outlines, similar but not identical to the original image. All figures are for illustrative purposes only. Outlines are not to scale. A1, Hypsilophodon foxii, outlined from [34]; A2, Haya griva, based on IGM 100/2017, outlined from [33]; A3, Jeholosaurus shangyuanensis, based on IVPP V15939, outlined from [20]; B1, Tenontosaurus tilleti, outlined from [48]; B2, Dryosaurus altus, outlined from [49]; B3, Probactrosaurus gobiensis, based on PIN 2232/39-1, outlined from [68]; B4, Iguanodon atherfieldensis, outlined from [50]; C1, Brachylophosaurus canadensis, outlined from [69]; C2, Maiasaura peeblesorum, outlined from [69]; C3, Hypacrosaurus stebingeri, outlined from [69]; C4, Corythosaurus casuarius, outlined from [53]; D1, Yinlong downsi, based on IVPP V18637; D2, Psittacosaurus neimongoliensis, outlined from [55]; D3, Auroraceratops rugosus, outlined from [29]; D4, Protoceratops andrewsi, based on AMNH 6251, outlined from [70]; D5, Leptoceratops gracilis, based on AMNH 5205, outlined from [56]; D6, Montanoceratops cerorhynchus, based on AMNH 6466, outlined from [28]; D7, Ischioceratops zhuchengensis, based on ZCDM V0016; E1, Triceratops horridus, based on AMNH 4842, outlined from [59]. Arrows indicate position of fourth trochanters.
Fig 11.
Right tibia and fibula of holotype of Ischioceratops zhuchengensis (ZCDM V0016).
Posterolateral view. Abbreviation: rfe, right femur; rfi, right fibula; rti, right tibia.
Fig 12.
Strict consensus tree of ornithischian relationships produced by analyzing a data matrix of 61 taxa and 346 characters (see text and Supplementary Information); Values above nodes represent bootstrap proportions.
Values beneath nodes indicate Bremer support. Bremer support values of +1 or less are not shown. Tree length = 1046 steps, RI = 0.707, CI = 0.385.
Fig 13.
Position of Ischioceratops zhuchengensis among the Ceratopsia as recovered by an analysis of ceratopsian phylogenetic relationships.
A single most parsimonious tree was produced by analyzing a data matrix of 34 taxa and 162 characters (see text and Supporting Information). Values above nodes represent bootstrap proportions. Values beneath nodes indicate Bremer support. Bremer support values of +1 or less are not shown. Tree length = 321 steps, CI = 0.598, RI = 0.797. Bootstrap values are shown above branches.