See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/263844805 A new species of Kryptobaatar (Multituberculata): the first Late Cretaceous mammal from Inner Mongolia (P.R. China) Article in Bulletin de l'Institut Royal des Sciences Naturelles de Belqique, Sciences de la Terre · January 2001 CITATIONS READS 13 339 3 authors, including: Thierry Smith Royal Belgian Institute of Natural Sciences 215 PUBLICATIONS 3,383 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Chelinioid studies View project PalEurAfrica View project All content following this page was uploaded by Thierry Smith on 11 July 2014. The user has requested enhancement of the downloaded file. BULLETIN DE L'INSTITUT ROYAL DES SCIENCES NATURELLES DE BELGIQUE SCIENCES DE LA TERRE, 71-SUPP.: 29-50.2001 BULLETIN VAN HET KONlNKLlJK BELGISCH INSTITUUT VOOR NATUURWETENSCHAPPEN AARDWETENSCHAPPEN, 71-SUPP.: 29-50,2001 A new species of Kryptobaatar (Multituberculata): the first Late Cretaceous mammal from Inner Mongolia (P. R. China)l by Thierry SMITH, Dian-Yong GUO & Yan SUN SMITH, T., GUO, D.-Y. & SUN, Y., 2001 - A new species of Introduction Ktyptobau~ar(Multituberculata): the first Late Cretaceous inammal from Inner Mongolia (P. R. China). Bulletin de I'lnstit~rt royal des Sciences nutrri-elles de Belgique, Sciences de la Terre, Supplement 71: Many Cretaceous mammal species were described from 29-50, 9 pls., 8 figs., 2 tables; Bmxelles-Brussel, Deceinber 15, 2001. the Mongolian part of the Gobi desert (see KIELAN- - lSSN 0374-6291 JAWOROWSKAet al., 2000, for an overview), most of them collected from the Djadokhta Formation at Bayn Dzak Abstract (American-Mongolian expeditions in 1 WOs, see SIMPSON,1925, 1928; Polish-Mongolian expeditions in Multituberculates are the best represented mammals of the Late Crctaceous 1963 to 197 1, see KIELAN-JAWOROWSKA,1970, 1974) and in Asia and most of them are from Outer Mongolia. The djadochtatheri- from Ukhaa Tolgod (American-Mongolian expeditions oidean multituberculate Kr)ptobaut~i-mandihuensis n. sp. is described on the basis of two skulls froin the Upper Cretaccous localiiy of Bayan since the 1990s, see ROUGIERet al., 1997; WIBLE& Mandaliu (Inner Mongolia, People's Republic of China). The main charac- ROUGIER,2000). However, knowledge on Late ters that differentiate it from tlie type species K. dashzevegi KIELAN- Cretaceous mammals from the Chinese portion of the JAWOKOWSKA,1970 are: the base of the zygomatic arch situated at the level Gobi desert was based on an axis of Khuduklestes bohli- of tlie anterior root of the P4 and the narrow anterior extent of the orbit, the "V" shape of the palatoinaxillary suture between the tlvo major palatine ni N~ssovet al., 1994 discovered in 1929-1930 by the fonmina, the high and thick part of the dentary under the mandibular Sino-Swedish expedition at Tsondolein-Khuduk in the diastema. the long and low part of the dentary iinder the mandibular notch, Gansu Province (BOHLIN,1953, p. 41-42, fig. 20). More the anteroposteriorly short coronoid process. the presence of 5 cusps on the recently, the Sino-Canadian expedition (1987 to 1990) middle row of Ml and on the labial row of ml, the long p4. the Iiigh ratio reported the discovery of several mammalian skulls in p4:ml length, and the robust il. The presence of this species in lnner Mongolia extends the palacogeographical distribution area of the Bayan Mandahu, Inner Mongolia (DONG,1993, p. 2000; djadochtatherioideans to the soutliern part of the Gobi Basin. Neveiiheless, JERZYKIEWICZet al., 1993, p. 2 188-2 189) 250 km north- morphological differences between K. tnandahitensis from lnner Mongolia east from Tsondolein-Khuduk (Fig. 1). The specimens and K. dushzevegi from Outer Mongolia suggest a palaeogeographical iso- are yet undescribed so far. lation within the Djadochtatherioidea group during the Campanian. The two skulls of multituberculate mammals described Key words: Mammals, Multituberculata, Djadochtatherioidea, Laie below were discovered during the Sino-Belgian expedi- Cretaceous. Inner Mongolia. tion in Inner Mongolia at Bayan Mandahu in 1996 (Fig. a 1). A nearly complete skeleton of a large multituberculate Résumé and four other skulls and postcranial remains have also been found at Bayan Mandahu, in 1995 and in 1999 Les multiiuberculés sont les mammifères les mieux représentés du Crétacé respectively, and will be described later. supérieur d'Asie et la plupart d'entre eux sont connus de Mongolie exté- rieure. Le multituberculé djadochtatherioidéen Ktyptobaumr r~~unduliuen.~i.s n. sp. est décrit sur basc de deux crânes découverts dans le Crétacé supé- The monophyletic order Multituberculata is represented by rieur de Bayan Mandahu (Mongolie intérieure, République Populaire de 86 genera belonging to at least 17 families (see KIELAN- Chine). Les caractères principaux qui différentient cette espèce de I'espèce- JAWOROWSKA& HURUM,2001) distributed in the whole type K. dushzevegi KIELAN-JAWOROWSKA.1970 sont: la base de l'arcade zygomatique située au niveau de la racine antéricure de la P4 et la partie world except the Australian region and Antarctica. Two antérieure de l'orbite étroite, la forme en V de la suture palatomaxillaire large groups are distinguished within the Multituberculata: entre les deux forainens palatins majeurs, le dentaire haut et épais sous le the paraphyletic suborder "Plagiaulacida" sensu KIELAN- diastème mandibulaire, le dentaire long et bas sous I'incisure mandibulaire, JAWOROWSKA& HURUM(2001) which is distributed from le processus coroiioïde court antéro-postérieurement, la présence de 5 cus- the Middle Jurassic (Bathonian of England, FREEMAN,1976, pides sur la rangée médiane de la M 1 et sur la rangée labiale de la m 1, la longue p4, le rapport longueur p4lm I élevé et la robuste i 1. La présence dc 1979; see also BUTLER,2000) to the Early Cretaceous, and cette espèce en Mongolie intérieure permet d'étcndre l'aire dc répartition the apparently monophyletic suborder Cimolodonta which paléogéographique des djadochtatherioidéeiis jusqu'au sud du Bassin du is distributed from the Early Cretaceous to the Late Eocene Gobi, Toutefois, les différences morphologiques entre K. manduhuensis de Mongolie intérieure et K. dashzevegi de Mongolie extérieure sont en faveur d'un isolement paléogéographique au sein du groupe des Djadochtatherioidea durant le Campanieii. 1) This paper is a contribution to Research Project M0/36/001 and to Excavation Project BL/36/C 12 financially supported by Mots-clefs: Mammifères, Multitiibcrculés, Djadochtatherioidea, Crétacé the Federal Office for Scientific, Technical and Cultural supérieur, Mongolie intérieure. Affairs (SSTC-DWTC). 3 O Thierry SMITH, Dian-Yong GUO & Yan SUN Fig. 1 - Map of the Gobi Basin showing the Inner Mongolian locality of Bayan Mandahu, which has provided the material of Krvptobaator mandahuensis and the Outer Mongolian localities of Bayn Dzak, Tugrugeen Shireh and Ukhaa Tolgod, whkh have provided the material of K. dashzevegi. (specifically Priabonian, "Chadronian" of Wyoming and tionships (SERENO& MCKENNA,1995; KIELAN- Saskatchewan, KRISHTALKAet al., 1982; "Chadronian" of JAWOROWSKA,1996; ROUGIERet al., 1996; GAMBARYAN Nebraska, OSTRANDER,1984). The plagiaulacidan multi- & KIELAN-JAWOROWSKA,1997; BUTLER,2000; WIBLE& tuberculates possess many plesiomorphic characters such ROUGIER,2000; KIELAN-JAWOROWSKA& HURUM, 200 1). as, notably, three upper incisors, an upper premolariform Multituberculates are generally considered as more basal canine (if present), five to four upper premolars, four to than archaic therians, symmetrodonts, marsupials and three lower premolars, and the absence of the third lin- placentals, but more derived than monotremes. What - gual row of cusps in M 1 but an incipient postero-lingual some authors disagree about is the relative position of the ridge may be present. On the other hand, the cimolodont triconodonts in comparison with the rnultituberculates. rnultituberculates differ by several apomorphies, the most The same anatomical characters treated in phylogenetic - typical of which are: loss of the first upper incisor, a max- analyses are considered as homoplasies or synapomor- imum of four upper premolars, loss of the two first lower phies according to the authors. Triconodonts are situated premolars, third lower premolar peg-like or lost, increase between multituberculates and symmetrodons (ROUGIER or reduction in size of p4, and development of a third lin- et al., 1996, WIBLE& ROUGIER,2000) or considered as gual row of cusps in M 1. Most of the genera are known more primitive than multituberculates and also only from isolated teeth or fragments of jaws, and thus, monotremes (Hu et al., 1997; JI et al., 1999) in the early during many years, the phylogenetic relationships of the mammal phylogeny. rnultituberculates, which share several homoplasic char- With the exception of the genus Buginbaatar KIELAN- acters with rodents, were poorly understood. The study of JAWOROWSKA& SOCHAVA, 1969, al1 the Mongolian Late skulls and postcranial bones of Mongolian Late Cretaceous multituberculates belong to one monophyletic Cretaceous cimolodontan multituberculates, essentially group: the Djadochtatherioidea KIELAN-JAWOROWSKA& during the last thirty years by Zofia KIELAN-JAWOROWSKAHURUM, 200 1. This superfamily includes the genera: and CO-workers,has permitted to describe more precisely Djadochtatheriurn SIMPSON,1925; Ktyptobaatar KIELAN- the particular