Cranial morphology and phylogenetic relationships of Amynodontidae Scott & Osborn, 1883 (Perissodactyla, Rhinocerotoidea) Author Veine-Tonizzo, Léa Géosciences Rennes, UMR 6118, Université de Rennes 1, CNRS, 35000 Rennes (France) and JURASSICA Museum, Route de Fontenais 21, CH- 2900 Porrentruy (Switzerland) and Department of Earth Sciences, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K 1 S 5 B 6 (Canada) and Beaty Centre for Species Discovery, Canadian Museum of Nature, PO Box 3443, Station D., Ottawa, ON, K 1 P 6 P 4 (Canada) leaveinetonizzo @ cmail. carleton. ca (corresponding author) leaveinetonizzo@cmail.carleton.ca Author Tissier, Jérémy JURASSICA Museum, Route de Fontenais 21, CH- 2900 Porrentruy (Switzerland) and American Museum of Natural History, Central Park West at 79 Street, US- 10024 New York (United States) jeremy. tissier 123 @ gmail. com jeremy.tissier123@gmail.com Author Bukhsianidze, Maia Georgian National Museum, 3, Purtseladze street, Tbilisi 0105 (Georgia) maiabukh @ gmail. com maiabukh@gmail.com Author Vasilyan, Davit Author Becker, Damien JURASSICA Museum, Route de Fontenais 21, CH- 2900 Porrentruy (Switzerland) and Department of Geosciences, University of Fribourg, CH- 1700 Fribourg (Switzerland) davit. vasilyan @ jurassica. ch damien. becker @ jurassica. ch davit.vasilyan@jurassica.ch text Comptes Rendus Palevol 2023 2023-03-20 22 8 109 142 http://dx.doi.org/10.5852/cr-palevol2023v22a8 journal article 305635 10.5852/cr-palevol2023v22a8 f100859e-029b-47d5-8854-258ca1d5d772 1777-571X 14238834 urn:lsid:zoobank.org:pub:3201699E-0180-4DB2-9C25-60EE6A783D85 CADURCODONTINI The tribe Cadurcodontini includes Zaisanamynodon , Amynodontopsis , Cadurcotherium and Cadurcodon . This clade is defined by five unambiguous synapomorphies (Bremer index = 1): the postglenoid process of squamosal is dihedron 42 (2); the upper premolars labial cingulum is always present 83 (0); the olecranon fossa of the humerus is low 193 (1); the mandibular condylar process is high 287 (0); the talonid of m3 is longer than the trigonid 288 (1). Zaisanamynodon is placed as a sister group of the clade formed by Amynodontopsis , Cadurcotherium and Cadurcodon . The monophyly of Zaisanamynodon is supported by three synapomorphies (Bremer index = 1): the zygomatic process progressively diverges from the maxilla 37 (0); the lingual cingulum of the upper molars is usually absent 114 (2); the third posterior loph is present on P4 298 (1). ZSN-KKS-28-IPB is a sister group of Zaisanamynodon borisovi , which supports its identification (Bremer index = 1). Zaisanamynodon borisovi ( sensu lato , = ZSN-KKS-28-IPB and Z. borisovi ) differs from Zaisanamynodon protheroi by a single autapomorphy: the paracone fold of M3 is weak 289 (1). Zaisanamynodon protheroi is defined by only one unambiguous autapomorphy: the lingual cingulum of the lower premolars is reduced 148 (0), but five other ambiguous autapomorphies might support the distinction of the two species. Cadurcotherium and Amynodontopsis form a clade supported by three unambiguous synapomorphies (Bremer index = 1): the rostral end of the nasal bones is narrow 24 (0); the mandibular ramus is inclined posteriorly 60 (0); the labial cingulum of the lower molars is always absent 159 (3). Amynodontopsis is sister group to Cadurcotherium , and they share three synapomorphies (Bremer index = 2): the zygomatic process progressively diverges from the maxilla 37 (0); the presence of a sagittal crest on the basilar process 44 (1); the M3 paracone fold is weak 289 (1). Amynodontopsis jiyuanensis has six autapomorphies: nasal notch is above P1-3 3 (0); nasal bones are long 26 (0); paraoccipital process of the occipital is little developed 48 (1); upper molars antecrochet is usually present 110 (2); M1-2 metastyle is long 120 (1); M1-2 posterior part of the ectoloph is concave 122 (1). Cadurcotherium is supported by two synapomorphies (Bremer index = 2): the upper molars lingual cingulum is always absent 114 (3); the lower molars hypolophid is almost sagittal 161 (2). Cadurcotherium cayluxi is defined by two autapomorphies: the M1 postfossette is present 127 (0); the m3 talonid is equal or smaller than trigonid 288 (0). Cadurcotherium minum is defined by one autapomorphy: upper premolars labial cingulum is always absent 83 (3). Cadurcodon is placed as a sister group to the clade formed by Cadurcotherium and Amynodontopsis . Cadurcodon is supported by six unambiguous synapomorphies (Bremer index = 2): the ramus coronoid process is little developed 61 (1); the I1 is absent 71 (1); the i1 is absent 76 (1); the upper molars antecrochet is usually absent 110 (1); the upper postcanine diastema is short 291 (1); the I3 size is distinctly smaller to I2 293 (2).