42 3 2004 7 VERTEBRATA PALASIATICA pp. 177 192 figs. 1 5 1) ( 100044) : 2 : ( Dzungariotherium orgosense) ( ) ( Paraceratherium yagouense sp. nov. ) : ;, ;DP2 M1,, Indricotherium Dzungariotherium Paraceratherium 3, Paraceratherium :, : Q915. 877 : A : 1000-3118(2004) 03-0177 - 16 1 (1990),, p3 p4, Dzungariotherium orgosense, 2002 7,,,,,,, Gromova (1959) U 1) ( :40232023) ( : KZCX2-103) :2003-12 - 26
178 42 2 Dzungariotherium orgosense Qiu ( = Chiu), 1973 ( 1 3 ; 1) IVPP V 13571, P2 ;V 13807, P3 ;V 13862, P4, ; V 13808-1 3, P4 M2,P4 ;V 13809, M3 ;V 13810, M3, ;V 13811, M3 ;V 13812, M3 ;V 13813, M3, ;V 13814, i1 ;V 13815, p2 ;V 13816, p2 ;V 13817-1 4, p3 m1 m3 ;V 13818, m2 ;V 13819, P2 (V 13571, 1 A),,,S, 45,,,,,, ;, ;, ; V ;, ( ) P3 (V 13807, 1 B), ;,,,,,,,,,, P2, V P4 (V 13808-1, 1 C) ( ) P3,,, P3, M1, 2 M2, P4 M2 (V 13808-2, 1 D),,, 20 mm,,,, ;,,, ;,, ;, 5 M3, M2,, (V 13812), ; (V 13809 V13811, 1 E), 1Π3 3 M3 (V 13813), M3 (V 13810 1 F), ; M3 M2,
3 : 179 M3 (V 13811, 1 E) ( ) 97. 5 mm, ( ) 66 mm 1 Fig. 1 Occlusal view of upper cheek teeth of Dzungariotherium orgosense A. right P2 (V 13571, reverse) ; B. right P3 (V 13807, reverse) ;C. left P4 (V 13808-1) ; D. left M2 (V 13808-2) ; E. right M3 (V 13811, reverse) ;F. left M3 (V 13810) ; scale = 5 cm (A C same scale ; D F same scale) (i1, 2), Gromova (1959) Paraceratherium pro2 horovi,,,, Gromova,, ; ; 52. 5 mm, 36. 6 mm, 32 mm p2 (V 13815, 3 A),,, ;, ;,, p3 (V 1381721, 3 A) U ;
180 42,, ( ), ;, ;, ( 3 A1), ;,, p4 (V 1381722) p3 m1, U, ;, 2 (V 13814) ; Fig. 2 Lower incisor (V 13814) of Dzungariotherium orgosense A. mesial view ; B. lateral view ; scale = 5 cm ( ), ;,, ;, p3, p3, p3 p4 m1 (V 1381723, 3 A) m2 (V 13818, 3 C),,, p3 m1 m3 (V 1381724, 3 B), U, ;,,, ; ; ;, ( ) 71 mm ; ( ) 62 mm( ) 131 mm, 117 mm, 102 mm p3 p4 (1990), Indricotherium Paraceratherium, Indricotherium, Paraceratherium p3,p4, Paraceratherium, Indricotherium p3 p4,,, ( 1) Indrico2 therium Paraceratherium, M1,
3 Fig. 3 Lower cheek teeth of Dzungariotherium orgosense A. left p2 (V 13815) left p3 m1 (V 13817-1 3), A1. buccal view ; A2. occlusal view ; A3. lingual view ; B. left m3 (V 13817-4), B1. occlusal view ; B2. buccal view ; C. right m2 (V 13818, re2verse), C1. occlusal view ; C2. buccal view ; scale = 5 cm
182 42 Indricotherium Paraceratherium Dzungariotherium 1959 Gromova,, 2 3 : Indricotherium transourali2 cum ( = I. asiaticum, I. minus, Baluchitherium grangeri ), Paratheratherium prohorovi ( = Aralotherium prohorovi) P. bugtiense ( = Baluchitherium osborni), Indricotherium Paraceratherium, 2 3 Gromova (1959) Indricotherium Paraceratherium, Indricotherium, Paraceratherium Paraceratherium Indricotherium ( ) 6 :1) P1 ( ) ;2) P2 ( ) ;3) ( ), ( ), ( ) ;4) M3 ( ) ;5) (i1) ( ) ;6) p3 p4 ( ), ( ) Indricotherium Paraceratherium ( ) :1) P3 P4 ( ) ;2) p3 ( ), ( ) 2 :1) i1 p2, ( 1) ;2) m3 (V 13817-4, 3 B) ( ) 62 mm Indricotherium Paraceratheri2 um 56 mm Dzungariotherium 1973 D. orgosense Indricotherium Paraceratherium (,1973),, M2 M3 ; ( ), D. orgosense,, Indricotherium Paraceratherium ( 1) D. orgosense P1,P2,M2 M3,,M3, D. orgosense, ( 1) ( Gromova, 1959, p. 12), D. orgosense Dzungariotherium, D. turfanense, 1978, D. orgosense Lucas Sobus (1989) D. orgosense Lucas Sobus (1989), Indricotherium Dzungariotherium Para2 ceratherium Indricotherium, I1,, -, ; Para2
3 : 183
184 42 ceratherium Dzungariotherium, I1, -, (2003), Indricotherium Paraceratherium Dzungariotherium 3,,Gromova (1959) Paraceratherium Indricotherium, Gromova (1959), Paraceratherium Indricotherium, Dzun2 gario2therium (1973), Paraceratherium, Indricotherium,,, Dzungariotherium Indricotherium,, Indricotherium Paraceratherium Dzungariotherium,,, ( ) Paraceratherium yagouense sp. nov. ( 4 5 ; 2) IVPP V 13820, DP1 DP4 M1 M2 P2, V 1382121 2, M3 Paraceratherium, P. bugtiense, DP1 DP4 ; DP1, P1,,M1, ; (DP1 ),,, ; ; ; ; Yagou,,, ( ), 85 mm,, 85 mm, 10 mm, 17 18 mm, DP2, 65 mm, DP3, 20 mm,,, DP4,, - 25 mm ; 70 mm ;,,, M1, 95 mm ( ), ( 4 C,5 B),,, ( 4 C,5 B),,, ;,,
4 ( ) (V 13820, ) Fig. 4 Skull (V 13820, holotype) of Paraceratherium yagouense sp. nov. A. right lateral view ;B. crown view of upper cheek teeth ;C. dorsal view abbreviations : L. lacrimal ; M. maxilla ; N. nasal ; Pm. premaxilla ; scale = 5 cm
186 42,, 65 mm, 38. 5 mm 20 mm, 40,, M2 (36 mm), 70 mm DP1 470 mm DP1,,,,,, ;, DP2 ;, ;DP1 DP3,,, DP4,, ;,, ; ; DP3 P2,, ; 3 :,, ;, M1,, ; ;,,, ;, ;,,,,, ;, M2, V 13821-1 ( 5 A) V 13821-2 M3 D. orgosense, ;, ;, 68. 5 mm 88. 5 mm, ( P. bugtiense Benaratherium callstrati ), V 13820, Paraceratherium :1) ;2), ;3) ( ),, ;4) DP1, ( Indricotherium ) ;5) ;6) M1 ( ), Benaratherium, Gabunia (1964), Benaratherium
3 : 187 5 ( ) Fig. 5 Paraceratherium yagouense sp. nov. A. Left M3 (V 13821-1),A1. buccal view ;A2. occlusal view ;B. anterior part of skull (V 13820, holotype), left antero2lateral view scale = 5 cm, 4 abbreviations as in Fig. 4,,,,, Paraceratherium Dzungariotherium 2, Paraceratherium 5, P. prohorovi ( 2), M1,,, P. prohorovi Paraceratherium lipidus M2 (,1978) P. prohorovi,m3 P. prohorovi, Paraceratherium tienshanense (,1959 ;,1962) Paraceratherium Paraceratherium sui (,2003),,
188 42 2 Table 2 Comparison of cheek teeth of some indricotheres (mm) Paraceratherium Indricotherium yagouense sp. nov. bugtiense 3 prohorovi transouralicum V 13820 ( Holotype) F. 2Cooper,1934 Gromova, 1959 DP1 L 23. 9 21 32. 5 34 W 18. 4 20 28 28 DP2 L 28. 3 39 42 47 W 36. 6 38 42 51 DP3 L 37 48 53 54 W 47. 7 43 54 58. 5 DP4 L 60 62 73 W 58 53 70 M1 L 74. 3 75 73 89 W 71 72 84 103 H 70 76 3 Measured and calculated from plate. Paraceratherium bugtiense, Paraceratherium Paraceratherium bugtiense V 13820 (Forster2Cooper, 1934, Fig. 20, Pl. 64 : fig. 22), :1), P3 P4, 140 mm, 43 mm ; V 13820 200 mm 80 mm 2), DP2 ; V 13820 DP4 3), V 13820 ( 4C,5B) 4) DP2 DP4,,, ; V 13820, DP3 DP4,,,,, P. bugtiense, Paraceratherium,, M1, ( ) Paraceratherium M3,,, M1 3 1), Dzungariotherium orgosense ;, Paraceratherium : P. yagouense
3 : 189 2) Indricotherium Paraceratherium Dzungariotherium 3, Paraceratherium, Indricotherium Dzungariotherium Gabunia (1964) Benaratherium,, 3) Dzungariotherium orgosense,,, IND RICOTHERES ( PERISSODACTYLA, MAMMAL IA) FROM OL IGOCENE IN LINXIA BASIN, GANSU, CHINA QIU Zhan2Xiang WANG Ban2Yue DENG Tao ( Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences Beijing 100044) Key words Linxia Basin of Gansu Province, Oligocene, Indricotheriidae Summary The indricothere fossils from the Linxia Basin, Gansu Province, were first reported by Qiu et al. in 1990. The fossils were purchased from the Dongxiang county drugstore, allegedly from the deposits near the bottom of the Jiaozigou ravine. The age of the fauna was then considered as early Miocene because of the presence of a segment of proboscidean tusk among the purchased fossils. In 2002, while checking the fossils kept by a local dragon2bone dealer in the Hezheng County, the authors of the present paper found some well preserved Oligocene fossils, such as teeth of Tsagan2 omys, Aprotodon, some chalicothere, skull and teeth of indricotheres etc, allegedly from a ravine called Yagou of the Dongxiang County. Subsequent geologic work not only confirmed the provenance of the Yagou fossils, but also found that fossils from both Yagou and Jiaozigou ravines are from the same fossiliferous level, i. e., from the lower part of the Jiaozigou Formation. We failed to find any traces of proboscidean fossils in both localities. It is highly possible that the proboscidean tusk from the Jiaozigou ravine came from some overlying deposits, then mixed with the Oligocene fossils. Without the proboscidean fossils the lower part of the Jiaozigou Formation can well be assigned to late Oligo2 cene, rather than early Miocene as previously suggested. The indricothere fossils are the best part of the Yagou fossils so far collected and may be of greater significance in age determination. Dzungariotherium orgosense Qiu ( = Chiu), 1973 (Figs. 1 3 ; Table 1) Material IVPP V 13571, right P2 ; V 13807, right P3 ; V 13862, right P4 ; V 1380821 3, left P4, left and right M2 ; V 13809 13813, 5 M3 ; V 13814, left i1 ; V 13815 13816, 2 left p2 ; V 1381721 4, left p3 m1 and m3 ; V 13818, right m2 ; and V 13819, distal part of Mc (or Mt) III. Brief description The P2 is triangular, longer than wide. Labial wall strongly convex, with long parastyle. Protoloph S2form, extending postero2lingually. Metaloph slightly longer than proto2 loph, attenuated labially ; hypocone strongly enlarged. Small crochet and crista are present. Medisi2 nus is wide, blocked lingually at crown base. Postfossette is large. The tooth is surrounded by con2
190 42 tinuous cingulum. The P3 is trapezoid in form. Protoloph is curved back, joining with large hypo2 cone, with a groove on lingual wall between protocone and hypocone. Metaconule forms a ridge, linking ectoloph and hypocone, closing the medisinus. Postfossette is small, open posteriorly. Crista is present, but small and rounded. Cingulum is as in P2. The P4 is similar to P3, but larger, with deeper parastyle fold, lingual groove of protoloph anterior to hypocone, and metaconule more curved. The M2 is trapezoid in form, longer externally and wider anteriorly. Parastyle is very prominent and parastyle fold is deep. Protocone has narrow anterior, but wide posterior constriction folds, and a narrow fold on flattened lingual surface. Antecrochet is large. Metaloph shorter than protoloph, with narrow anterior hypocone constriction fold. Anterior and posterior cingula are high2ridged, but the lingual and labial cingula are weak. The M3 is triangular, with the vestigial, highly reduced posterior end of ectoloph. Cingulum is as in M2. The i1 is close to that of Paraceratherium prohorovi described by Gromova (1959), but with the cross2section of the crown more laterally compressed and the upper ridge undeveloped. The crowns of all the lower premolars are surrounded by continuous cingula. The p2 is very small, single2rooted. Its crown is triangular in form. The main cusp is large, sending 3 ridges : an2 terior, postero2lingual and posterior ones. The P3 is also triangular in form. The metalophid is al2 most complete, with long ridge2formed paraconid and angled postero2labial corner, covered with tu2 bercles. The transverse ridge of the hypolophid is very long. Entoconid is completely merged with hypolophid, with its lingual end anteriorly curved. The p4 is transitional between p4 and m1 in structure, trapezoid in form. Metalophid is U2shaped, with long transverse lophids, but rounded postero2labial corner. Entoconid is enlarged and curved anteriorly. The lower molars differ from the premolars in having higher paralophids and entoconids, more rounded postero2labial corners of meta2 lophids, shallower labial valleys and weaker cingulum. Comparison and discussion Morphologically, the above described p3 and p4 from Yagou are almost identical to those from Jiaozigou described by Qiu et al. (1990), possessing mixed fea2 tures of both Indricotherium and Paraceratherium. These features include the tapering of the premo2 lars anteriorly, the well developed and postero2lingually extended paralophid, the complete conflu2 ence of the entoconid with the hypolophid (more similar to Paraceratherium), but the angled poste2 ro2labial corner of the metalophid with accessory tubercles in p3 (more similar to Indricotherium). In size the p3 and p4 from Yagou are slightly larger than those from Jiaozigou, but both are larger than those of Indricotherium and Paraceratherium ( Table 1). It is reasonable to assign them to one and the same species. Based on the better preserved material from Yagou, the dental characters of this large Linxia indricothere form is better known. Morphologically it is intermediate between Indricotherium and Paraceratherium. It is similar to Paraceratherium in the following features : loss of P1 ; triangular form of P2 ; protocone lingually flattened, with vertical groove in upper molars ; more reduced vestige of the posterior end of ectoloph in M3 ; the large tubercle on mesial side in the i1 ; the narrowed an2 terior parts in p2 and p3 ; and the confluence of the entoconid with hypolophid. On the other hand, the Yagou form is close to Indricotherium in having more posteriorly extended hypocone in P3 P4, the deeper parastyle folds in upper cheek teeth, the longer protoloph, the angled postero2labial cor2 ner of the metalophid and the deeper labial valley in p3 and p4. However, the teeth of the Yagou form are larger and may be of higher crowned as compared with those of above 2 genera (see Table 1). Dzungariotherium orgosense was created by Qiu in 1973, based on skull with lower jaw of a very old individual with its teeth heavily worn. Morphologically speaking, the only comparable teeth between the Yagou and the type of Dzungariotherium orgosense are the M2 and M3. They resemble each other very closely in having flattened protocone lingual surface with vertical groove and cingu2 lum, the anterior protocone constriction groove, and the large antecrochet etc. Their slight size dif2
3 : 191 ferences between them (see Table 1) seem to fall within the range of variation of a species, which has been recognized as particularly large in indricotheres ( Gromova, 1959). Lucas and Sobus ( 1989) suggested synonymizing Indricotherium and Dzungariotherium with Paraceratherium, which has priority over the former two, based on the notion that the morphologic differences between the three genera were in fact merely sexual ones. Recently Ye et al. (2003), based partly on lower jaw and incisors, clearly expressed their notion to maintain the 3 genera as separate and valid ones, with which we fully agree. In fact, in her monograph on indricotheres Gro2 mova (1959) already demonstrated in great detail the distinctive characters on skull, lower jaw, teeth, and almost every limb bones between Indricotherium and Paraceratherium. If we agree with Gromova s opinion, it is inevitable to consider Dzungariotherium as a valid genus as well. Dzun2 gariotherium can be characterized, on the one hand, by the mixed features of both Indricotherium and Paraceratherium, on the other hand, by the strongly reduced and upturned symphysis, rather unique characters among the indricotheres. Paraceratherium yagouense sp. nov. (Figs. 4 5 ; Table 2) Holotype IVPP V 13820, a juvenile skull with left and right DP1 DP4, M1, and une2 rupted M2 and right P2. Other material V 13821-1 2, left and right M3 of one and the same individual. Diagnosis Small, close to P. bugtiense in size. Length of muzzle anterior to DP1 not sur2 passing DP1 DP4. No upper incisors, canines, and P1. Cheek teeth high crowned, with thin layers of cement. M1 possesses crown height equaling the maximum crown length, protocone with lingual groove ; DP2 M1 with large antecrochet, anterior protocone and hypocone constriction grooves, high and ridge2formed anterior and posterior cingula, lacking lingual cingulum, often with pillar2formed tubercles in the middle of anterior cingulum, medisinus, postfossette and posterior to antecrochet. Etymology Yagou is the locality where the fossils were collected. Brief description The muzzle is strongly reduced in length. The premaxilla and the maxilla anterior to the DP1 form a thin plate, 85 mm high at the level of the posterior end of the nasal pro2 cess of the premaxilla. Neither incisors and canines, nor their roots, can be detected on the alveolar border. The posterior wall of the nasal notch lies above the posterior part of the DP4. The large in2 fraorbital foramen is above the posterior end of the DP3, and the anterior rim of the orbit is above the middle of the M1. The maxilla extends postero2superiorly, forming a long lobe ( Figs. 4C and 5B : M). The facial part of the lacrimal is very high (Figs. 4C and 5B : L). The frontal surface of the nasals is convex with sagittal suture, and their ventral surface concave. The posterior part of the lateral borders of nasals hangs down. The supraorbital process is large. The postglenoid process is 65 mm long, laterally compressed. The distance between the postglenoid and mastoid processes is 40 mm. A thin layer of cement can be seen on labial walls of all the upper cheek teeth. The DP1 is the least worn of the deciduous teeth. It is triangular, with very small protoloph, but long and complete metaloph. The inner cingulum is well developed anterior to the hypocone. The labial cingulum is fine. Both DP2 and DP3 are heavily worn, leaving closed medisinus in the center of the crown. In DP4 the anterior and posterior protocone constriction grooves and the anterior hypocone constriction groove are clearly shown. The antecrochet is large, blocking the medisinus when not heavily worn. An accessory pillar is present in the postfossette. The anterior and posterior cingula are well deve2 loped, ridge2like in form. The M1 is high crowned, with its crown height equaling the maximum length of the ectoloph. The straight protoloph is longer than the metaloph, which is curved with its posterior border convex. Its protocone, hypocone and cingulum are constructed as in DP4. There are also accessory pillar2formed tubercles. Two M3 of the same individual (V 1382121 2) have been
192 42 referred to the present species, chiefly because of the presence of cement cover and their small size, comparable with the Yagou skull but evidently smaller than those of D. orgosense. However, the antecrochet is smaller and the accessory tubercles are less developed than in the above described M1. Comparison and discussion Although small compared with majority of the other indrico2 theres, the above described skull is much larger than any other rhinocerotids. The following charac2 ters of the skull show its Paraceratherium affinity : the wide distance between the postglenoid and mastoid processes, the strongly reduced muzzle, the wide and thin nasal bones, the presence of metaloph in DP1, the high crowned cheek teeth, and the presence of vertical groove on the flattened inner surface in M1 (and possibly in other upper molars) etc. Four of the five Paraceratherium species ( P. prohorovi, P. tienshanense, P. lipidus, and P. sui) can easily separated from the Yagou form simply by size. They are all much larger. In ad2 dition, the complete loss of the upper incisors and canines, the particularly large antecrochet, the deep constriction grooves and the peculiar pillar2formed tubercles expressed in the upper cheek teeth of the Yagou form are rather unique among the indricotheres so far described. Paraceratherium bugtiense is only species of the genus comparable with the Yagou form in size. However, comparison of similarly young aged skull parts of the two forms shows clearly that they are of different species. In P. bugtiense the part of the skull anterior to the orbit is very low, with shal2 low and low nasal notch, and low and wide maxilla and lacrimal bones (see Forster2Cooper, 1934, Fig. 20), the DP2 DP4 with small antecrochet and shallow constriction grooves (see Forster2Coo2 per, 1934, Pl. 64, Fig. 22). These are quite different from those in the Yagou form as described above. Thus a new species is created for it : Paraceratherium yagouense. Concluding remarks 1) Two indricothere species coexisted in the Linxia Basin : the larger Dzungariotherium orgo2 sense and the smaller Paraceratherium yagouense. 2) The evolutionary history of the indricotheres seems to be more complicated than previously conceived. Indricotherium, Paraceratherium and Dzungariotherium are three valid genera, and can not be lumped into one single genus Paraceratherium as Lucas and Sobus (1989) once suggested. 3) The age of the fossil2bearing deposits of the Linxia Basin is late Oligocene rather than early Miocene as previously suggested by Qiu et al. (1990). References Chiu C S( = Qiu Z X, ),1962. Giant rhinoceros fromloping, Yunnan, and discussion on the taxonomic characters of Indri2 cotherium grangeri. Vert PalAsiat ( ),6(1) : 57 71(in Chinese with English summary) Chiu C S( = Qiu Z X, ),1973. A new genus of giant rhinoceros from Oligocene of Dzungaria, Sinkiang. Vert PalAsiat ( ),11 (2) : 182 191(in Chinese with English abstract) Chow M C ( = Zhou M Z, ),Xu Y X( ),1959. Indricotherium from Hami basin, Sinkiang. Vert PalAsiat ( ),3 (2) : 93 96 Forster2Cooper C, 1911. Paraceratherium bugtiense, a new genus of Rhinocerotidae from Bugti Hill of Baluchistan 2 preliminary no2 tice. Ann Mag Nat Hist, 8 (8) : 711 716 Forster2Cooper C, 1924. On the skull and dentition of Paraceratherium bugtiense : a genus of aberrant rhinoceroses from the lower Mi2 ocene deposits of Dera Bugti. Philos Trans R Soc London, Ser B, 212 : 369 394 Forster2Cooper C, 1934. The extinct rhinoceroses of Baluchistan. Philos Trans R Soc London, Ser B, 223 : 569 616 Gabunia L K, 1964. La faune de mammif res de l Oligocene du Benara. Tbilici : Mezniereba Press. 1 266(in Russian with En2 glish summary) Gromova V, 1959. Giant rhinoceroses. Tr Paleont Inst, 71 : 1 164(in Russian) Lucas S G, Sobus J C, 1989. 19. The systematics of indricotheres. In : Prothero D R, Schoch R M eds. The Evolution of Perissodac2 tyls. New York : Oxford Univ Press. 358 389 Qiu Z X( ),Xie J Y( ),Yan D F ( ),1990. Discovery of some early Miocene mammalian fossils from Dong2 xiang, Gansu. Vert PalAsiat ( ),28 (1) : 9 24(in Chinese with English summary) Xu Y X( ),Wang J W( ),1978. New materials of giant rhinoceros. Mem Inst Vert Paleont Paleoanthrop, Acad Sin ( ), (13) : 132 140(in Chinese) Ye J ( ),Meng J ( ),Wu W Y( ),2003. Discovery of Paraceratherium in the Northern Junggar Basin of Xinjiang. Vert PalAsiat ( ),41 (3) : 220 229