56 41 Esthonyx ( Esthonychidae) 1), 4 Deltatherium Cope, 1881, (Matthew,1937) Matthew(1937) Deltatherium, Chriacus Actocyonidae, Deltatherium, ( Panto

Transcription

1 VERTEBRATA PALASIATICA pp fig. 1 ( ) ( Yuesthonyx gen. nov. ) 1) ( ) ( ) ( Yuesthonyx tingae gen. et sp. nov. ), Esthonyx ( Meiostylogon) ( Interogale) Megalesthonyx Megalesthonyx Adapidium, ( Yuesthoncidae Fam. nov. ) Q , 20,, 1978, (pseudictopid) (,1980), Tillodontia Marsh,1875 ( ) Yuesthonychidae fam. nov. ( ) Yuesthonyx gen. nov. ;, W ;,,, ; Yuesthonyx gen. nov., Megalesthonyx Rose, 1972, Adapidium Young, 1937, Huananius Huang et Zheng, 1999 (1979), Esthonychidae, Adapidium 1) ( : KF980301) :

2 56 41 Esthonyx ( Esthonychidae) 1), 4 Deltatherium Cope, 1881, (Matthew,1937) Matthew(1937) Deltatherium, Chriacus Actocyonidae, Deltatherium, ( Pantodonta) (McKenna,1975), (Van Valen, 1978) (Lucas and Schoch, 1998) (McKenna and Bell, 1997) Deltatherium,, P4,, Torrejonian Deltatherium, Yuesthonyx P1/ 1 ( Yuesthonyx P1/ 1 ),, ( Yuesthonyx Huananius, ) ; ( ) Yuesthonyx gen. nov. Yuesthonys tingae gen. et sp. nov. Yu, Esthonyx, ( ) Yuesthonyx tingae gen. et sp. nov. ( 1), P3 M3 ( IVPP V 10176) P2 M3 (V ), c m3 (V ), p4 m3 (V ), m1 2 (V ) Esthonyx, :?,1,4,3/?,1,4,3, P1/ 1,P1/ 1 P2/ 2 ; P2, P4, ;p2 W, ;M3, V, ;,, 1km ;,,, P2, P2 P2 ( P1), P2 1) McKenna and Bell (1997), Esthonychidae Tillotheriidae Gazin(1953), Gazin

3 1 : ( ) ( Yuesthonyx gen. nov. ) 57, (10. 75mm) M1 2 P2 (C1), (2mm), 3 P2, V ,,,, ( ),,, P3 4,, V P4,,,,, P4, P3 P3,P4 P4, M1 2,,M2 M1,,, W,,,,,, M3 M1 M2 V , p1 p1 (V ),, (p1), (715mm) m1,, (p2), (11mm), m1 2 p2, m1 p3 p4 V p4 p4, V, 1 ( ) Table 1 Measurements of the cheek teeth of Yuesthonyx tingae gen. et sp. nov. (mm) P2 P3 P4 M1 M2 M3 L W L W L W L W L W L W V V p2 p3 p4 m1 m2 m3 L W L W L W L W L W L W V V V

4 ( ), ( IVPP V 10176) (V ) Fig. 1 Yuesthonyx tingae gen. et sp. nov., maxilla and mandible 1,1a. left upper cheek teeth, occlusal view (stereophotographs), 2 ; 2. partial skull, ventral view, 1. 5 ; 3,3a. left mandible, occlusal view (stereophotographs), 2. 2 ; 4. left mandible, labial view, 1. 5

5 1 : ( ) ( Yuesthonyx gen. nov. ) 59,, m1 2 V,,,, V,,, m3 m1 2,, ( Taligrada Cope, 1883),, 30, ( ),,,, P1/ 1,,P4/ 4,,P1/ 1,P4/ 4,, 3, Megalesthonyx hopsoni, ( ) ( Adapidium huanghoense Young,1937) (,1979 ; Stucky and Krishtalka, 1983) ( Huananius youngi Huang et Zheng, 1999) 3, Megalesthonyx,p1,,, W, Yuesthonyx,, P2,,Rose (1972) Megalesthonyx hopsoni Esthonyx Esthonyx Trogosus (Stucky and Krishtalka, 1983) Rose, Megalesthonyx Esthonyx Trogosus,, ( Puercan Torrejonian ),

6 60 41 ( Lofochaius) (,1977 ;,1989), ( Huananius) (Huang and Zheng, 1999), ( Meiostylodon) (, 1975) ( Anchilestes) (,1977 ;, 1989), Meiostylodon Esthonyx, Huananius ( Interogale datangensis Huang et Zheng, 1983), ( Tiffanian Clarkforkian ), Esthonyx Interogale (,1989) Megalesthonyx Interogale,, Huananius M1 2, (Clarkforkian), Azygonyx Esthonyx ( Gingerich, 1989), (late Wasatchian) Megalesthonyx (Rose, 1972) (Cuisian) Franchaius Plesiesthonyx (Baudry, 1992) Esthonyx (Tong and Wang, 1998),, Trogosus Tillodon, 4, Basalina (Lucas and Schoch, 1981) ( Kuanchuanius) (, 1963a ;,1990) ( Chungchienia) (Chow, 1963b ; Chow et al., 1996) ( Adapidium ) ( Young, 1937 ; Gazin, 1953 ;, 1979 ; Stuky and Krishtalka, 1983), : 1) ( Higotherium hypsodon) cf. Trogosus sp. (Miyata and Tomida, 1998a,b),,, Megalesthonyx ( Stucky and Krishtalka, 1983 ; Baudry, 1992 ; Lucas, 1993 ) Bridgerian : Adapidium huanghoense Young, 1937, (F12) ( ), (1937) m2 3,, Gazin (1953), (1979) ( ) P4 M1 Stucky Krishtalka (1983), Megalesthonyx Adapidium huanghoense Megalesthonyx Basalina basalensis Dehm et Oettingen2Spielberg, 1958, Ganda Kas, (Taeniodonta),,,Lucas Schoch (1981) 1)

7 1 : ( ) ( Yuesthonyx gen. nov. ) 61, (Lucas and Schoch, 1998) Kuanchuanius shantungensis Chow, 1963,, ( ), m2 3 ( IVPP V 2764), Trogosus, (Lucas and Schoch, 1998) Kuanchuanius? danjiangensis Cheng et Ma, 1990,, ( ) M1 ( GV 86033) Trogosus, (,1990) Chungchienia sichuanenica Chow, 1963,, ( ) (p3 p4) ( IVPP V 2767),, ( Edentata),,, Tillodon Higotherium (Chow, et al., 1996 ; Miyata and Tomida, 1998a),,, Tillodon Higotherium, Chungchienia lushia Chow et al., 1996,, ( ) Higotherium hyposodon Miyata et Tomida, 1998, Akasemachi Akasaki, m2 3 (NSM2PV ), Trogosus Tillodon,, ( Miyata and Tomida, 1998a) Cf. Trogosus sp. (Miyata et Tomida, 1998b), Iwajima Akasaki, Lofochaius brachyodus Chow et al., 1973 (?) ( ) ( IVPP V 4239), Lofochaius, (1989) Lofochaius Harpyodus Plethorodon, Lofochaius (Lucas, 1993 ; Wang et al., 1998 ; Ting, 1998 ; Lucas and Schoch, 1998) P1 P2,,P4,, ( ),, P3, Lofochaius Meiostylodon zaoshiensis Wang, 1975, ( ) M1 2 ( IVPP V 4869),, Esthonyx Anchilestes impolitus Qiu et Li, 1977, ( ) (Zalambdalestidae), (1989) P3 M2 p4 m3 ( IVPP V 4315),P4,,

8 62 41, Anchilestes impolitus, Interogale datangensis Huang et Zheng, 1983, ( ) ( IVPP V 6861), (Anagalida), i2, (,1989) p1, Huananius youngi Huang et Zheng, 1999, ( ) P3 M3 p3 m2 ( IVPP V 11700),,,,p3,,p4 V, p4,, Yuesthonyx tingae gen. et sp. nov., Dysnoetodon minuta Zhang, 1980, ( ), ( IVPP V 5837) P3 P4,p4,, Dysnoetodon minuta Plethorodon chienshanensis Huang et Zheng, 1987,, ( ) ; ( IVPP V 8304) (Taligrada), (de Muizon and Marshall, 1992 ; Wang et al., 1998) V 8304,P4,P2 P3 P4, V P2 8,, Dysnoetodon minuta Plethorodon chienshanensis,, Lofochaius Anchilestes 4,,, Meiostylodon zaoshiensis, Huananius youngi, YU ES THONYX, A NEW TILLODONT ( MAMMAL IA) FROM THE PAL EOCENE OF HENAN TONG Yong2Sheng WANGJing2Wen FU Jing2Fang ( Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sceince Beijing ) Kay words Henan, Late Paleocene, Tillodontia

9 1 : ( ) ( Yuesthonyx gen. nov. ) 63 Summary This paper reports a new tillodont species, Yuesthonyx tingae gen. et sp. nov., belonging to a new family, Yuesethonychidae. The new taxa is created based on the materials collected from the Late Paleocene Dazhang Formation of the Tantou Basin, Henan Province, in The associated mammal fossil in the Dazhang Formation is a mandible of pseudictopid ( Anagalida) ( Tong and Wang, 1980). We also briefly review the Asian tillodonts and noticed the tillodonts were diversified during Early Paleocens. Tillodontia Marsh, 1875 Yuesthonychidae fam. nov. Type genus Yuesthonyx gen. nov. Diagnosis A long diastema between canine and second premolar, mesostyles of upper molars present or well developed and connecting with paracone and metacone to form W2shaped ectoloph ; trigonids of lower molars less compressed anteroposteriorly relative to esthonychids, paraconid less reduced, metaconid tall and thin, and hypoconulid shift lingually. Including genera Yuesthonyx gen. nov., Megalesthonyx Rose, 1972, Adapidium Young, 1937, Huananius Huang et Zheng, Remarks Yuesthonychidae differs from the known esthonychids as mentioned in diagnosis, which supports that Adapidium may represent a new family of tillodonts proposed by Chow and Wang (1979). Deltatherium Cope, 1881 is recently considered to be related to the Tillodontia (Lucas and Schoch, 1998), or allocated to the Tillotheriidae ( = Esthonychidae) as a subfamily (McKenna and Bell, 1997). Despite its systematic position is uncertain, Deltatherium is distinctly different from the known yuesthonychids in having less molariform P4, and in lacking mesostyles on upper molars. It also differs from the contemporaneous yuesthonychids by the absence of P1/ 1 ( present in Yuesthonyx), and the pre2 and postprotocrista of upper molars extending to the paracone and metacone, respectively. Yuesthonyx tingae gen. et sp. nov. (Fig. 1) Holotype A partial skull with left P3 M3 ( IVPP V 10176). \ ; Referred specimens left maxilla with P2 M3 (V ), left mandible with c m3 (V ), left mandible with p4 m3 (V ), and left mandible with m1 2 (V ). Diagnosis Close to Esthonyx in size, with dental formula 3? / 3? Canine large, post2canine diastema short, but diastema between P1/ 1 and P2/ 2 long ; P2 triple2rooted, P4 with small metacone ; p2 double2rooted. Paracone and metacone of upper molars conical, mesostyle developed to form a strong W2shaped ectoloph, conules clear, and pre2 and postcingulum short and weak ; metacone, postmetacone crista, and metaconule of M3 less reduced. Lower molar paraconid distinct, separated from metaconid by a V2shaped valley ; metaconid high and thin ; metastylid absent ; hypoconulid lingually located, and entoconid isolated from hypoconulid. Rostrum constricted abruptly at the position of P2, and mandibular symphysis unfused. Locality and horizon Wangpo Village, 1km west of Dazhang, a small town of Songxian County, Henan Province ; Dazhang Formation, Nongshanian Age, Late Paleocene. Remarks Dazhang specimens assigned to the Tillodontia is based on the following features : rostrum constricted at the position of P2, P1/ 1 reduced, long diastemae present between P1/ 1 and P2/ 2, molariform P4/ 4, and morphological similarities of cheek teeth to the known tillodonts. The presence of mesostyles on the upper molars of Dazhang specimens is comparable to those of Megalesthonyx hopspni, Adapidium huanghoense, and Huananius youngi, and differs from that of

10 64 41 other known tillodonts. The Dazhang specimens differ from Megalesthonyx in having large canines, the presence of p1, and in lacking metastylids of lower molars. Adapidium has laterally hypsodont molars, presence of metastylids on lower molars, and wide stylar shelf on upper molars, which distinguish it from the Dazhang specimens. Huananius has isolated mesostyle on the labial cingulum of upper molars, differing from the new species, in which the upper molars have mesostyles connected with postparacone crista and premetacone crista, forming a W2shaped ectoloph. The Dazhang species is distinct in having large canines, triple2rooted P2, upper molars with developed conules, and less developed pre2 and postcingulum. Rose ( 1972 ) recognized Megalesthonyx hopspni is intermediate between Esthonyx and Trogosus in time and in many morphologic characters. But Stucky and Krishtalka ( 1983 ) considered this hypothesis is less plausible. Usually, Megalesthonyx, together with Adapidium, is placed a position between the Esthonychinae and the Trogosinae, or in the Trogosinae in the phylogenetic hypotheses of tillodonts ( Stucky and Krishtalka, 1983 ; Lucas, 1993 ; Chow et al., 1996 ; Lucas and Schoch, 1998). The discovery of the Dazhang species suggests the tillodonts with mesostyles on upper molars are possibly related to early diversification of tillodonts. Therefore, a new family Yuesthonychidae, including Yuesthonys, Megalesthonyx, Adapidium, and Huananius, is proposed. References Baudry M, Les Tillodontes (Mammalia) de l Eocene inferieur de France. Bull Mus Natl Hist Nat, Paris, Ser 4, C, 14 : Cheng J ( ),Ma A C( ),1990. The new mammalian materials from the Eocene of Liguanqiao Basin. Vert PalAsiat ( ), 28(3) : (in Chinese with English summary) Chow M C( ),1963a. Tillodont materials from Eocene of Shantung and Honan. Vert PalAsiat ( ),7 (2) : (in Chinese with English summary) Chow M C, 1963b. A xenarthran2like mammal from the Eocene of Honan. Sci Sin, 12 : Chow M C( ),Wang B Y( ),1979. Relationship between the pantodonts and tillodonts and classification of the order Pantodonta. Vert PalAsiat ( ),17(1) :37 48(in Chinese with English summary) Chow M C( ),Chang Y P ( ), Wang B Y( ) et al., New mammalian genera and species from the Paleocene of Nanhsiung, N. Kwangtung. Vert PalAsiat ( ),11(1) :31 35(in Chinese with English summary) Chow M C, Wang J W, Meng J, A new species of Chungchienia (Tillodontia, Mammalia)from the Eocene of Lushi, China. Am Mus Novit, (3171) :1 10 Dehm R, Oettingen2Spielberg T, Palgontologische und geologische Untersuchungen im Tertigr von Pakistan. 2 : Die mitteleocgnen Sgugetiere von Ganda Kas bei Basal in Nordwest2Pakistan. Abh Bayer Akad Wiss, Math2Nat, Abt, N F, 91 :1 54 de Muizon C, Marshall L G, Alcidedorbignya inopinata ( Mammalia : Pantodonta) from the early Paleocene of Bolivia : Phylogenetic and paleobiogeographical implications. J Paleont, 66 : Gazin C L, The Tillodontia : an early Tertiary order of mammals. Smithson Misc Collect, 121 :1 110 Gingerich P D, New earliest Wasatchian mammalian fauna from the Eocene of northwestern Wyoming. Composition and diversity in a rarely sampled high2floodplain assemblage. Univ Michigan Papers on Paleontol, 28 :1 97 Gingerich P D, Gunnell G F, Systematics and evolution of the genus Esthonyx (Mammalia, Tillodontia) in the early Eocene of North America. Contrib Mus Paleontol Univ Michigan, 25 : Huang X S( ), Zheng J J ( ), A new anagalid from upper Paleocene of Nanxiong Basin, Guangdong. Vert PalAsiat ( ),21 (1) :59 63(in Chinese with English summary) Huang X S( ),Zheng J J ( ),1987. A new pantodont2like mammal from the Paleocene of Chienshan Basin, Anhui. Vert PalAsiat ( ),25 (1) :20 31(in Chinese with English summary) Huang X S( ),Zheng J J ( ),1999. A new tillodont from the Paleocene of Nanxiong Basin, Guangdong. Vert PalAsiat ( ),37 (2) :96 104(in Chinese with English summary)

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