37
ON A NEW SAUROPODA, WITH NOTES ON OTHER FRAGMENTARY REPTILES FROM SZECHUAN Br C. C. YOUNG INTRODUCTION In the summer of 1936, Prof. C.L. Camp and the present author excavated important parts of a Sauropoda skeleton at Hsikuashan near Junghsien (Szechuan) and collected some other fragmentary Dinosaur remains in the vicinity of the same area. I have already given a short geological account of this discovery elsewhere.' The whole collection was then transported to the Cenozoic Research Laboratory in Peking and prepared in the laboratory under my supervision. The main part of the material represented by the skeleton from Hsikuashan will be described first. Other fragmentary specimens are only briefly enumerated as an appendix. I wish to express here my sincere thanks to Dr. C.L. Camp with whom I greatly enjoyed the friendship of a common field trip. I am grateful for having had the opportunity to rely upon his experienced skill in the delicate work of excavation. I Young, C. C. f937. New Tri*uic and Cretaceous Reptiles u China. Bull. Genl. Soc. China,VoI. XVII, No.1, pp. 113-118.

On a New Sauropoda, with Notes on Other Fragmentary Reptiles from Szechuan

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Page 1: On a New Sauropoda, with Notes on Other Fragmentary Reptiles from Szechuan

ON A NEW SAUROPODA, WITH NOTES ON OTHER

FRAGMENTARY REPTILES FROM SZECHUAN

Br

C. C. YOUNG

INTRODUCTION

In the summer of 1936, Prof. C.L. Camp and the present author

excavated important parts of a Sauropoda skeleton at Hsikuashan near

Junghsien (Szechuan) and collected some other fragmentary Dinosaurremains in the vicinity of the same area. I have already given a short

geological account of this discovery elsewhere.' The whole collection was

then transported to the Cenozoic Research Laboratory in Peking andprepared in the laboratory under my supervision. The main part ofthe material represented by the skeleton from Hsikuashan will bedescribed first. Other fragmentary specimens are only briefly enumerated

as an appendix.

I wish to express here my sincere thanks to Dr. C.L. Camp withwhom I greatly enjoyed the friendship of a common field trip. I amgrateful for having had the opportunity to rely upon his experienced skillin the delicate work of excavation.

I Young, C. C. f937. New Tri*uic and Cretaceous Reptiles u China. Bull. Genl. Soc.China,VoI. XVII, No.1, pp. 113-118.

Page 2: On a New Sauropoda, with Notes on Other Fragmentary Reptiles from Szechuan

280 Bulletin, of the Geological Society of China

L DESCRIPTION OF THE SAUROPODA FROM

IISIKUASHAN, JUNGHSIEN.

Sub-order Sauropoda

Family Brachiosauridae

Sub-family Helopodinae

Genus Omei.saurus Young (gen. nov.)

With the genotype Omeieavrus junghsienth Young (sp. nov.)

Omeisdurus junghsiensis Young (sp. noy.)

Material and mode of occurrence. The first bone to be discovered

in the site was a left femur. Later on, we found part of the sacrum

still in juxta-position with the femur, a condition suggesting that there

was a chance of unearthing the complete skeleton. Thus, we decided

to carry out a limited excavation lasting approximately two weeks.

As shown in the published section, the site lies a few yards E of

the river which runs N-S and E from the Junghsien city, and just below

a hard sandstone cliff. This fossiliferous cliff, about 8 m high and probably

artificially cut in the fields, compounds to a ridge of harder sandstone.

The first bone was observed about one half of a meter above the ground.

The matrix is a kind of greenish gray sandstone dipping toward north

and lying approximately 200 meters above the Tzeluting limestone. The

true dip of the strata near the quarry is 15e, somewhat obscured by

strong cross-bedding.

We started to quarry from the top, the trench being about 8 meter

long (S.N.) and 2.5 meters wide (along the cliff) just above the bone bed.

After working for three days with four coolies and one technician,

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Young :New' Sauropoda, & Other Reptiles from Szechuam 281

numerOus ribs began to appear in the middle part of the quarried area,

about 1,5 meter below the top. Since the beds showed a considerable dip

towards the north, the main work had to be done in that direction.1ollowing the extension of the bones, we tried to enlarge the quarry in

S.E. direction by about two meters.

After some 12 days of excavation, most of the bones were exposed

as is shown in Textllgure 1. The orientation of the animal is somewhat

dubious. Judging by the location of the ribs, sacrum and the major

part of the vertebrae, it would seem that the animal was lying in S.N.

direction, so that the head should have to be searched for further north.

Yet, several neck vertebrae and the left humerus were found just south

of the major portion of the skeleton. In spite of several trials, noadditional bones were discovered in either direction. It may be inferred

that the body of the animal was twisted and dismembered in the water.

Since the west part of the site serves as a path and also since . con-

siderable portion of the cliff has disappeared, both the head and the

tail have apparently been lost.

All the bones are dark grey or even black in color. Most of them

are very soft and weathered, the preservation of which required careful

solidifying and binding processes. We were short of shellac, so we used

the native gum. Finally, some 2300 kg of bones with matrix were packed

in 24 boxes and transported by coolies with great difficulties from

J unghsien to the highway station at Peimuchen, about 200 lis away.

The specimens were subsequently prepared in the Cenozoic

Research Laboratory in Peking under my supervision. The pieces

determined compose:

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282 BulLetin of the Geological Society of China

Fig. 1 - The Omeiszirus skeleton as it was found in situ. C. coracod. F, f ibula.

Fe. femur. H. humerus, f, ilium. Is, hchium. Nv. neck.vértebrae. P,pubis. R, ribs. S, sacrum. Sc, scapula V, vertebrae. Much reduced.

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Young:-.New Sauropoda, & Other Reptiles from Szechuan 283

4 neck vertebrae

3 pre-sacral vertebrae

13 sacral and post-sacral vertebrae in juxta-position

8 ribs, representing almost the entire left sideThe left scapula and coracoid (the distal part of the

scapula is damaged)

Fig. 2- Omth wsyusg7uiensis. A Deck.veTtebra. Lateml. upper. lower, freut und

back view., much teduced.

A complete left humerus

2 lIla (upper border damaged)

2 Ischla (complete)

The left pubis almost complete

The upper part of a left femurThe complete left fIbula

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284 Bulletin of the Geological Society of China

The most characteristic porTions of this material consist of the

almost complete pelvic girdle and the partly preserved fore and hind limbs.

The study of these pieces leads to the conclusion that we are dealing

with a Sauropoda.

I. DESCRIPTION

Vertebrae

Neck vertebrae. There are at least fuur pieces safely referable

to the neck vertebrae. One is an almost complete specimen (Fig. 2).

Of the three other ones, more fragmentary, two are illustrated in Figs. 3

and 4.

Fig. 3 - Omeisaurus yunghsiensis. Another neck.vcrtebra. Lower, upper and la.

teral views. Much reduced.

The best specimen A (Fig. 2), slightly deformed but rather well

preserved, probably represents the seventh or eighth vertebra when cOnl

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Young:New Sauropoda, & Other Reptiles from Szech.uan 285

Fig. 4 - Omeisaunss yunghsieissis. Neckvertebra. fragment. Much reduced.

pared with the neck of Helopus. It is of a long and complex type.The upper margin of the considerably elevated processus pseudospinosus

is straight and elongated, without a trace of the upward swelling soconspicuous in the case of Helopus zdanskyi and Ca.ma.rosaurus supremus.

The centrum, complete anteriorly and posteriorly, is of a typical

opisthccoekius type. Its lateral part is marked by a depression. The

various cavities (upper, middle and lower) are not yet well separated, but

distinctly indicated, the lower one being crossed obliquely by a sharp ridge.

Pre- and post-zygapophyses well preserved. The former shows a clear

articulating facet for the cavity observable below the pointed post-

zygapophysis of the preceding vertebra.

Spechnen B (fig. 3) is similar to specimen A but shorter. It therefore

must have been set further back on the neck. This piece is less complete

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286 Bulletin of the Geological Society of China

ana more crushed. But the same essential structures are recognizable.

The posterior part of the centrum and the post-zygapophysis are damaged.

The third specimen C (fig. 4) is only represented by its damaged

posterior part. The post-zygapophyses are gone. The posterior cavity

of the centrum is well indicated and large. Observed in lateral view, the

two oblique ridges separating the upper, middle and lower lateral cavities

are more prominent than in specimens A and B. This vertebra has to

be considered as belonging to a rather posterior part of the neck.

Of these three specimens, the first one is the most characteristicfor a systematic diagnosis. Its main features are: the strong development

and the straight. outline of the processus pseudospiiiosus, the smallness

of the centrum and the general lateral compression of the bone.

Other vertebrae. Back of the neck the vertebrae are represented

by a group of 15 segments. With the exception of the anterior three

which were lying rather dislocated within the deposits but nevertheless

approximately in contact with the other ones, all of them were found in

actual juxta-position. They may be listed as follows: two postero-dorsal

vertebrae; one dorso-sacral; three primary sacral; one caudo-sacral and

8 anterior caudal vertebrae. All of them are more, or less deformed.

The two isolated postero-dorsal vertebrae are represented merely

by the centrum (Fig. 5). Both are somewhat deformed. They are

opisthocoelic, the posterior cavity being rather strongly concave. In the

first one, the nerve canal is well preserved anteriorly. The second one

is laterally expanded due to the compression from the top. The depres-sion on the lateral side of the centrum is moderately deep. On neither

of the two specimens can any trace of a parapophysis be noted in the

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Young :New Sauropoda, & Other Reptiles from Szeclvuan 287

centrum. This fact agrees with the condition observed on Hélo puszdanskyi by Wiman, namely that back (and including) vertebra XXII the

parapophysis is no longer inserted in the centrum but shifts upwards,

being set rather high on the vertebrae immediately preceding the pelvis.

The preservation of the supposed dorso-sacral vertebra is just as

poor, with only the main central and lower part of the centrum preserved,

Fig. 5 Omthøiu yunghie,ith. Posti.ro.dorsal vertebrae. hagmete. Much

reduced.

in addition to being somewhat depressed. Lateral depression wl1 marked

on both sides. Posterior cavity of the centrum is deep.

The primary sacral group (Fig. 6) is composed of three vertebrae

as in the case of Helopus. Both the centrum and the dorsal spine are

co-ossified. They are obliquely deformed with the right side badly dam-

aged, so that most of the description is based on the left side. Never-

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288 Bulletin of the Geological Society of China

theless, the essential features are apparent and point to a characteristicauropod-type, closely resembling the figures and description given by

Osborn and Mook of Camaraiurus supremn Cope.

Fig. 6. Omdianis ysghsinsis. Sacta veitebiic. Much reduced.

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Young:New Sauropoda, & Other Reptiles from Szechuan 289

The centrums are more slender than ii the preceding vertebrae and

only moderately constricted. They are platycoelous. The so-called

sacricostal lobe is not preserved, but the three inferior bars of the sacral

ribs are well indicated. The superior bars are less complete, but at least

two of them can be distinguished. Connecting the two series of bars, the

sacral ribs develop as large plate-like lamellae which are well preserved

on the left side. On the right side they are only preserved at the base

and are badly deformed. These lamellae are slightly concave anteriorly.

Since the marginal border is but poorly preserved, it is difficult to deter-

mine their exact extension but it probably was the same as in Camara-

saurus. All the dorsal spines are apparently co-ossified. They are solid

and compact.

Caudal vertebrae. Behind the above described sacral vertebrae,

there are 9 caudal vertebrae represented in' our collection. As they were

found in actual connection with the sacrum, they surely form a natural

series. They show a similar but much less pronounced deformation as

the sacrum so that their characters can be ascertained with greater

accuracy than in the previous vertebrae. All of them lack the caudal rib

of the right side, being more or less complete otherwise.

The fist one (Fig. 7) represents evidently the so-called caudo-sacral

or first caudal vertebra. But its structure differs broadly from that

observed in the other Sauropoda available for comparison (for instance

CanwrasaurusJ. First of all, it was found entirely loose from the real

sacrum, with no indications whatsoever of co-ossification. In addition,

the centruin is not elongated but of the same shape as in the following

vertebrae. The caudal ribs develop as a fan-like plate, concave anteriorly,

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290 Bulletin of the Geologicol Society of China

largely preserved on the specimen. 4nother marked feature is thepresence, just above this place, of an independent bony wing, laterallyattached at the base of the dorsal spine. This wing is set transversally

to the expanded caudal rib and concave ventrally. This peculiar process

seems to represent a bony development connecting the pre- and post-zygapophyses, or else it corresponds to what Osborn and Mook call

Fig. 7 Omdsawtis ywghsienth. Csudo..aaiii vertd,ra. Much reduced.

the superior bar of the sacral rib in the real sacrum. But it looks too

small to have actually beei in function. The dorsal spine, almost com-

plete, is rather short. As shown in Fig. 7, the dorsal spine of the next

following vertebra is still adhering to the specimen.

The remaining caudal vertebrae may be de scribed together (Fig. 8).

Their centrum is well preserved, although somewhat deformed. The

caudal rib of the first one is still clearly palmated, but reduced con-

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Young:New Sazropod,a, & Other Reptiles from Szechuan 291

siderably. In the others it merely forms a short process, as is usual inSauropoda. In all of them the pre. and post-zygapophyses are well

preserved. The rugo ities of the dorsal spine are not so strong as in the

case of Tienshanosaurus, but clearly expressed. Though belonging to the

Fig. Omeisrus yunghsiuis. Eight caudal vertebrae. Much reduced.

anterior part of the tail, their tip is not broadly rounded as inCamarasauriis suprenvus, but rather acuminate like in Tienshanogaurus.

Corresponding to the caudal vertebrae, we have only two chevrons

represented (Fig. 9). They were found isolated besides the row of thecaudal vertebrae, so that their exact nosition is unknown. They aretypically Y-shaped but with the inferior blade much longer than the

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292 Bulletin of the Geologieat Society of China

superior fork. The fork itself is bridged in its upper part by lateralexpansions of its branches. When compared with the illustrations given

by Osborn and Mook of Camarasaurue, these two pieces probably represent

the fourth and fifth chevrons of the tail and thus belong to the fifth and

sixth caudal vertebrae described above.

On the whole, the most important characters displayed by the

above described specimens are: (1) the remarkable development of the

Fig. 9 - Omeisir*s yungluiensis 'evrons" of cauda! veitebree.

processtw pseudospinos'us, on the neck vertebrae: a 255 mm. long wing,

surprisingly straight. (2) The presence of only 3 real sacral vertebrae.(3) The broad trañsversal fan-like expansion of the caudal rib on the

first caudal vertebra (the same feature is only faintly indicated in thenext following vertebra and further on it disappears entirely).

RIBS.

As shown in the field sketch, Fig. 1, eight more or less complete

ribs were Cound scattered in situ. Five of them have the head

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Young:Nw Sauropoda, & Other Reptiles from Szechuan 293

Fig. 10 Omeisrus yunghsirnsis. Rib.. Much vcduced.

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294 Bidletin of the Geological Society of China

(tuberculum and capitulum) preserved or indicated. The other three are

only represented by paits of the shaft (Fig. 10). The largest specimen

reaches a length of almost two meters, about the size of the Iongst ribof Co,nwra«aurus supremus, judging from the reconstruction given by

Osborn and Mook.

Dimensions'

Cavic & DoRsAL VERTEBRAE

length breadth height Height from theNumber without Posterior Posterior base of centrum toof the tne upper bord of

Vertebra joints processus pseudo-spina dorsalis

Neck, spec. A 450 125 - -near the

base" " B 460 90 120 325

" " C 160* 148 330

PosterOdOrsat* 1 120 195 200 -Posterodorsal 2 140 - -Dorso-sacral 130 - -SACRUM

Total length of the three sacral centrums 320

Max. height from the base of the middle. ceutrum tothe tip of the spina dorsalis 640

Height of the spina dorsalis 250

I Owing to the mare or less dc1omed coeditioG of the various vertebrae and ,lb. sotne of thc

dimensions (marked by an asterisk) bave to be taken as approximations.

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Young:New Sauropoda, on Other Reptiles from Szechuan 295

(3) CAUDAL VERTEBRAE

No. Height Length of Width of Height of Width of Height ofCentrum Centrum Centrum Centrum Centrum

anterior anterior posterior posterior

(4) RIBs

1 500 115 210 160 190 165

2 590 140 175 170 - -3 570 100 140 175'- -4 530 94 170 200 140 177

5 500 105' 120 170 130 180'

6 500 94 145 170 125* 180'

7 475 75 120 165 120 145

8 470 95 115' 145' - -9 - 105 - - 115 175

No.

1

2

Preserved lengthalong the shaft

Distance between Maximumcapitulum and

tuberculum (ormaximum breadth

preserved)

middlebreadth

46

51

- --3 745 185 43

4 1650 219 65

5 1750 185 52

6 1250 ?125 36

7 852 195 26

8 25- -

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296 Bulletin of the Geological Society of China

SCAPULA AND CORACOID

The scapula is only represented by the proximal end, its anterior

part and the shaft being broken. Both the glenoid and coracoid borderare intact. The coracoid, on the contrary, is almost complete, only the

Fig n - Q,nejsrus ywighsie,ssis. Scapu1 &nd coracoad. Much reduced.

antero-inferior border being damaged. The two bones were found innatural connection.

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Young:New Sauropoda, & Other Reptiles from Szechuan 297

The preserved part of the scapula is too small too permit judgement

of the actual shape of the bone but, nevertheless, sufficient to indicate

sauropodian affinities. A tentative reconstruction is given in Fig. Ii,

based cn a complete scapula of Tienshanosaurus chitaiensis. The coracoid

is mainly characterized by its shortness. Usually, the oracoid of a

Sauropod (Camarasaurus, Helyus, Tienshanosaurus, etc.) is sub-rectang-

ular in outline, and its verticai and longitudinal dimenswxis are suhequal.

In our specimen the outline is disUlly rounded and the proximal breadth

measured along the scapula border exceeds considerably (almost twice)

the proximal-distal length. The bone is moderately concave inside and

moderately convex outside, and very thick in the glenoid part. The in-

ferior angle is set very close to the glenoid border. The coracold foramen,

iather big, is situated 53 mm. apart from the scapula border on theouter side; but on the inner side it lies almost in contact with the scapula.

The scapula border itself .i.s surprisingly straight, as in Camarasaurus,

instead of forming the open S-shape curve characteristic for Tien-

shanosaurus and Helopus.

Dimensions Szechuan Tienshano&nirus ti etopussp. chitaieiz4s zdanskyi

Maximum anterior-posterior breadth

along the scapula 454 250 312

Maximum trsversal breadth between

the scapula and the lower margin 233 125 70

Maximum breadth of the gtenoid

surface 93

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298 BulLetin of the Geotogil Socie(y of China

HUMERUS

Belonging to the same left side as the scapula and coracoid de-

sc:ribed above, we have a humerus which is almost intt, though somewhat

crushed and damaged at the distal end. The proximal part is considerably

Fig. t2 - Omeis, ujsissis. Ich hiimcvwr. Mucb reduced.

expanded with a concave antero-superior muscular fessa and a stiongdeltoid crest The Shaft i moderately strong. Its borders keep almost

straight for a considerable length and then, gradually, diverge to formthe distal expansion of the bone, which is very moderate. In this

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Young:New Sauropoda, & Other Reptiles from Szechuan 299

regard our form differs remarkably from Tiens nanosaurus but stands

close to Helo'pus. In the latter form, however, the shaft is b ilt strongerwith a characteristic bending. Distal fossa damaged but apparently not

very strong. Shaft hollow, at least in the middle part. Size snialler thai'

in Helopus but larger than in Tienshanosaurus.

Dimensions

PELVIC GIRDLE

With the exception of the right pubis, all the elements of the pelvic

girdle are preserred, a!though partly damaged.

¡liii.. On the two ita the superior expansion is partly missing.The other parts are rçpresented on one or the other of the specimens.

Both were therefore tentatively reconstructed as shown in the Textfigs.

13-14.

The left ilium is the best preserved, though the posterior part of

the upper expansion including the acetabular contact with the ischium is

missing. In the right one, the upper border of the fan-like expansion

is still more damaged but the ischiadic peduncle is for the most partpreserved. The tip of the pubic peduncle, however, is partly broken.

When compared with the ilium of other Sauropoda available, our

specimen displays some analogies to certain genera but, nevertheless,

Szechuan Tienshanosaurus Helopusspec. chitaiensis zdanskyi

Total length 845 680 910

Proximal breadth 335 302 363Distal breadth ?230 ?225 225Minimum breadth of shaft 143 115 1.75

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300 Bulletin of the Geological Society of China

Fig 13Omeisaurus ywghsieiuis. Left ilium. Much reduced, a

keeps an isolated pQsition. It Is evidently clo8er related to l4ienshizw.-as-

aurus and Fletopus than to Camarasauriie (cf. figure 18). The pubicpeduncle is perpendicular to the main axis of the bone as in Tienshawo,-

saurus, but set more forward than in Heiopue.and it looks remarkablyshorter than in both these forms. Still more remarkable is the extension

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Yowng:New Savropoda, & Other Reptiles from Szech.uan 301

of the acetabulum crest which extends to as far as the end of the pubicpeduncle.

Fig. 14 Omeisatrus yunghsiezsis. Right ilium. Much reduced.

Jschia (Figs. 15-16). Both ischia are nearly complete, only the

sU'perior margin Is somewhat damaged. On the right side, the shaft

is narrower but more rounded than on the left. On the whole, the

bone is rather robust, very different in its general shape from that of

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302 ßv.Uetin of thc Geologicol Scciety of China

Fig. 15 On*eua'rus y:mghsiensts. Left isdihim. Much reducid.

Camarasaurus but reminiscent of Helo pus and Tienshanosaurus. The

distal end is slightly expanded as in the case of Tienshanosaurus; less

expanded than in Helopus.

Pubis (Fig. 17). Only the left one is preserved. The ischial border

is broken up to the margin of the pubic foramen but it seems to bave

been of considerable expansion. The remaining part of the bone is strong-

ly built. Distal end more expanded than in Helopus.

How far the ischia and pubis were co-ossified along the inner border

like in Heiopv.s cannot be ascertained. But in any case, their distal parts

were free.

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Young :----New Sauropoda, & Other Reptiles from Szechuan 303

By its three elements the pelvic girdle is decidedly larger than in

both Helopus and Tienshcvnosaurus as shown in the following table.

Fig. 16 Omeisauriis yw*ghsensis. Right iachium. Muth rejuced.

Dimensions:

ilium

Oineis. Tiens hann Fie1op.

Maximum length 7723 570 570

Height above the acetabulum 825 300 274

(right) 584* 475 485

IschiumMaximum length. 683 560 647

(rightI 721*

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304 Bulletin of the Geological Society of China

Fig. 17 Omthaiirus ywsghsiith. Left pubis. Much reduced.

Pubù

right dia1 pert slightly crushed

Breadth at acetabuum ?313 285 211(right) ?307

Breadth at distal end ?13O 115 190(right) 131

Thicknes8 at distal end 66 65 87(right) ? 39

Maximum Jength 649 630-Breadth at acetabulum ?350 234-Breadth at distal end 194 ?185 138

Thickness at distal end 79 ? 60 87

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Young:New Sauropoda, & Other Reptiles from Szechuan 305

A reconstruction of the girdle is given in Fig. 18, made on the

basis of Tiens ho.nosaurus and Helopu3 reduced to the same scale.Our form differs in certain essential points from both genera, although

it seems to have a croser affinity to the latter genus than to the former.

A close relationship with Ti.enshanosaurus is excluded by the less open

shape of the anterior embayment of the ilium. In Helopus the acetabulum

is set much more backward and the pubis and ischium have a verydifferent shape: less expanded proximally and more constricted distally.

Fig. ¡8 O,,dansnjs yisglisiensis. Restored pelvk girdle (A), cnmperecI witb thoecol Hi#ISS (B) and Tienshsossru, (C), at the same scale

POSTERIOR LIMB

The posterior lijnb is only represented by a part of a left femur

and a left fibula.

The femur is preserved up to the part below the fourth trochanter,

which is very prominent and projects visibly even when viewed from the

anterior. The head is more differentiated than both Tiensha.nosaurus and

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806 BuUettn of th.e Geological Society of China

Helopus and appears to be a more advanced type. The distal part is

reconstructed in Fia. 19, using the general form of Helopus.

Fag. 19 Oevisainu ywaghsissu. Left mur. from three sidos. Much reduced.

The fibula is complete but dislocated above the distal end. It is along slender bone. The shaft is surprisingly round, and does not showany trace of the peculiar ridge which, starting from the inner side of

the proximal end, extends up to the anterior side of the distal end inmost other genera (Helopus, Camarusaurus, etc.).

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Young :New Sauropoda, & Other Reptiles from Szec1uan 307

Fig. 20 - Omeisaurus yunghsiensis. Left fibuIa Much teduced.

Dimensions:

Femur Omeis. Helopus

Maximum breadth (proximal) 300 294Lateral breadth above trochanter 274 -Anterior-posterior breadth above trochanter 103 -

Maximum length 682 618Proximal breadth ?100 150Distal breadth ..................... 114 102Minimum thickness of the shaft 65

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808 BulLetin of the Geologicat Society of China

RECONSTRUCTION & MOUNTING OF SKELETON.

Since most of the parts of the neck and dorsal vertebrae aremissing, we were unable to reconstruct the preserved anterior limbs and

ribs in a satisfactory way. The pectoral part with the humerus, however,

is mounted. On the other hand, the vertebrae found in association with

the sacrum, the pelvic girdle and the left posterior limb could easily be

joined by comparison with Helopus.

COMPARISON & DETERMINATION

That the above described material beloigs to a Sauropoda Is evident

frzn the characters of the vertebrae, the pectoral girdle, the humerus and

especially the pelvic girdle. As already stated, although the Szechuan

form stands close to Tienshanosaurus and Helopus, it nevertheless shows

a series of differences.

Omeisaurvs Tiens hanosaurua Helopus

Vertebra Processus pseudospinosusparticularky strong, theupper border being sur-prisingly short. Only 3sacral vertebrae withstrongly built sacral

ribs. First caudal ver-tebrae with fan-like,lattened caudal ribs.

Corczcoid Very short and with thescapula border straight.

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Young:New Sauropoda, & Other Reptiles from Szechuan 309

Humerus Proximal part well pal- Strongly con- Less expanded atmated; shaft rather aticted in the both endsstraight; distal part less middle.palmated

Ilium As in Helopus but aceta- Anterior em- Acetabulum settabulum more forward bayment more more posteriorlyin position, pubic pe- obtuse. on the boneduncle broad & strong.Acetabulum large withwall well developed.

hehl um Proximal end cons lerab- Proximal end Proximal end nar-ly expanded; shaft mas- and distal end row and distal endsive; distal end slightly less expanded more expandedexpanded

Pubis Proximal end considerab.ly expanded; shaft mas-sive; distal end moder-ately expanded.

Femur Head well differentiated.IV trochanter prominentand projecting.

? Proximal end ex-panded ; distal endnot expanded.

Head less differen-tiated. Ivtrochanter weak.

Combining all these differences, I find it rather difficult to refer

the Szechuan form to either of the mentioned genus, and still less to non-

Chinese forms such as Camarasaurus. It is therefore advisable to erect

a new genus and new species for it within the sub-family Helopodina..

The name chosen will be Omeisaurus yunghsiensis (gen. et sp. nov.)The specific name indicates the locality of the specimen, whereas the

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310 Bulletin of the Geologieal Society of China

«netic one is dedicated to the famous sacred mountain Otneishan, some

100 kkmeters west of Yunghsien.

11 'TRER REPTILIAN REMAINS FROM SZECHUAN.

As reported - my earlier paper', there are several localities in

Saechuan with remains of Dinosaurs and Crocodiles, besides the Hsikua-

shan locality. Unfortunately, most of the material is represented byrather fragmentary pieces only. Nevertheless, they are worth mention-

B

Fag. 21 - ?O,4smøua. Two tseth. RedUCed to 3/4.

Ing, -In order complete our present knowledge of the Reptiliam remains

from that province.

?Omeisauns yungh s Young (Fig. 21 A)

A single tooth was fourni near Chenchia about 10 II N.E. ofYunghsien city which apparently belongs to a Sauropoda referable tothe form describI above.

I Young C.C. New Tnasuc snd C,ctacsous Reptiles ¡n Cbino. Bull. G..l. Soc. China

Vol. XVII. No. I. 1937.

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Youig:New Sauropoda, & Other Reptiles from Szechuan 311

The tooth, the tip of. which ¡s broken, has a convex external and a

concave inner side as is usual in Sauropoda. On the inner aide the vertical

ridge is very faint and hardly indicated. No accessory cusp or swelling

at the lower inner part. The root is rounded. On the whole, the toothis very slender and may belong to a young individual.

When compared with a tooth of Helopus, our specimen is smaller,

less robust and lacks a basal inner swelling.

The horizon, where this tooth was found, lies immediately below

the typical Tzeliuching limestone and consequently represents a lowerzone than the Hsikuashan alte. Nevertheless, all the strata are appar-

ently Lower Crtaceous in age and the same form of Sauropoda may be

expected to occur all the way through. For this reason, I tentativelyrefer this single tooth to the Hsikuashan form.

TheroDoda gen. et sp. indet (Fig. 21, B)

A fragment of a tooth with tip and root broken, found in the

same locality as the above mentioned Sauropoda tooth, belongs to acarnivorous Dinosaur. It is laterally compressed. Part of the surface isdensely covered by enamel and finely striated but no traces of any serration

along the edge could be detected. Maximum length 7.8 mm; maximum

breadth, 4.8 mm.

The tooth is much smaller than the first tooth described by Dr.

Camp from Yunghsien' from a level apparently still higher than the

Hsikuashan zone.

I Camp. C. L. Ding.aur Remain. frem the Province of Szechuan. Chins-. China. Univ. Cal.aud. Dept. Geol. Sc.. Vol. 23. No. 14, p. 467.

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312 ultetin of the Geoogical Society of China

Dinosaur indet.

Besides the two teeth separately described above, our material

includes a number of fragments of limb-bones, but on account of their

poor preservation they cannot be determined with any degree of certainty.

Fig. 22 Dino,aotin, indet. Foot-bone.. Much reduced.

There are some phalanges with the terminus (Fig. 22) which seem to

suggest a carnivorous type because f the strong curvature and sharply

poiitted tip of the unequal digit

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Young:New Sauropoda, & Other Reptzes from Szechitan 813

Pholidosauridie indet.

In an earlier paper', I had referred to a "Sauropterygian indet." a

tooth found in the Tzeliuching limestone. Lately, remains of the sameform were found in a number of localities: in Chenchia, aSsociated with

the above described Dinosaur8; in Maanshan N.E. of Junghsien city; in

Shunohsiang, en route from Tzechung to Weiyuan; and in a place S. of

Chungking, according to Mr. S.C. Li of the Geological Institute of the

Western China Academy; in Hsiaobien, Wanhsien by Mr. L. P. Chia.

The final discovery of the anterior part of a skull in the Tzechietzelocality, when I revisited the site on my way back from Junghsien,definitely proves that in all these cases were are dealing with a long-nosed

Crocodiian.

On the Tzechietze specimen the whole nasal part with the pre-

n,axillae is preserved. The tip of the muzzle is broad; the nasal openings

large and confluent. The surface of the bone is undulating, with the

median line marked by a long depressed furrow. On the palatal surface,

there are 9 alveoli preserved on the right and 8 on the left side, all ofthem widely spaced (varying from 1/2 min to 20 mm). Teeth broken ormissing.

Dimen4ons:Length (preserved part) 200 mmMaximum breadth of the tip of the muzzle 64.5 mmMinimum breadth behind the bordering 45 nmMaximum posterior breadth 66 mmLength ol the vertebra 42 mmBreadth of the vertebra 51 mm

I Young. C. C. On the Reptilian Remain, of Tzeliuching formation near Chunking. SzechuanBull. Crol. Soc. China. Vol. XIV. No. I, 1935.

2 Dinosaur remains were aiso recovered from Maanshan and from Shuihobsieng but ar *ofragmentary to merit adesuiptioi,

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314 Bulletin of the Geological Society of China

Fig. 23Pbcfldossurkl. gen, md. Anterior part a skull. About 1/2.

Fig. 24 - Pbohdcsaurid. gee. jod. Teath and fragments of jaw. 1/2.

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Young:New Sauropok & Other Reptiles from Szechuan 815

Three lower jaw fragments found in Hsiaobien by L.P. Chia show

the same elongation of the maxilla and the same spacing of the alveoli.

In one of the specimens a tooth is still preserved and shows a similarity to

those previously tentatively referred to a "Sauropterygian" (Fig. 24, A. B).

Most of the isolated teeth are slender and small, except one specimen

from Maanshan, which is larger than the largest alveolus of the upperjaw described above. (Fig. 24, C, D.)

Fig. 25 - Phdidosaurid, gen. md. Vertebrae 1/2

A platycoelous vertebra from Hsiaobien may be referred to theaame form (Fig. 25).

By their general features these various specimens are obviouslyreierable to some Pholidosauridae. Strange fo say, no older MesozoicCrocodilian is so far known in China.