423. Discovery of the Fossil Giant Salamander (Megalobatrachus) in Japan*

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 45. pp. 197-200. pl. 29, April 10, 1962

423. DISCOVERY OF THE FOSSIL GIANT SALAMANDER (MEGALOBATRACHUS) IN JAPAN*

TOKIO SHIKAMA and YOSIIIKAZU HASEGAWA

Geological Institute, Yokohama National University

日本における化石ハンザキの発見:愛媛県喜多郡肱川村敷水の石灰岩採石場にある裂罅堆撰物たる敷水層より産した大サンショゥウオは.日本現世種に同定される.時代は上部蔦生層と同じく,更新世後期である。鹿間時夫・長谷川善和

Introduction their cordial thanks to them. The junior writer could observe some com- In the spring of 1958, Prof. K. NAGAI parative specimens by the courtesy of of the Geological Institute of the Univer- Drs. S. UENO, H. OZAKI and Y. IMAIZU- sity of Ehime sent the writers numerous I. He also could gain valuable M advice fossil bones and teeth collected at a and help for his research from Drs. Y. limestone quarry of Shikimizu, Hijikawa- OKADA, K. KOBA, H. TAKASHIMA, M. mura, Kita-gun, Ehime Prefecture (132•‹ SHIMIZU. T. MIYAO, Y. IKOMA and 1. 43'E. 33'28'N). Among them they found UCHIDA. The writers also express their a dental bone of a giant salamander. hearty thanks to these gentlemen. Further. in the summer of the same The fissure deposits at the quarry year, in a field survey jointly held by of Shikimizu. the Shikimizu bed of thc the Geological Institute of Yokohama writers, are mainly composed of brown National University and the Geological Institute of Ehime University, supported brecciated clay of 14 m thick, underlain by layers of black sand, yellow clay anc by the Caving Club of Shikoku, ['Mime News Press Co., the authorities of the gravel, also overlain by red clay and black humus. From the bed are found Hijikawa-mura. several specimens of the similar species were gained from the the following species. same quarry. The writers could obtain Cervus (Deperetia) praenipponicus SHINAMA valuable help and assistance from Prof. Sinomegaceroides yabei (SHIK AMA) K. NAGAI and the members of his Insti- Capricornis crispus (TEM.) Germs (Sika) nippon TEM. tute, Prof. K. Y.AM AGUCHI and the other members of the Caving Club of Shikoku, Maraca fuscata (BLVTH) Messrs. M. NOGUCHI, H. OCHI and the Metes leucurus kuzuiiensis SHIKAMA other gentlemen of Ehime News Press sus japonicus SCH. Ur Co., Mr. M. IKEDA and the other gentlemen artes ten SHII:AMAM of Hijikawa-mura, and wish to extend stela itatsiMu TEM. Leptas brachyurus TEM. & SCH. Sciurus sp. * Received Oct. 6, 1961, read Jan. 15, 1961. Clethrionomys sp.

197 198 Tokio SHIKAMA and Yoshikazu HASECAWA

Apodenuus sp. frontal and with right orbitosphenoid Sorex shinto THOAIAS have some simple parallel shallow Crocidura dsinezumi(TEM. & SCH.) grooves. Bone becomes thinner from ogera sp. M posterio-inner to anterio-outer sides. Rhinolophus sp. Length and width as preserved 28.5 and Pipistrellus sp. 15.6 mm respectively, thickness 4.7 mm. Phasianus sp. Right parasphenoid (figs. 2a. 2b). Ayes, gen. & sp. indet. A fragmental bone of anterior part Ophidia, gen. & sp. indet. of parasphenoid thin, flat, smooth and Lacertilia, gen. & sp. indet. broken in marginal part. Ventral and Bufo sp. dorsal surface of anterior part marked Rana sp. with shallow grooves running in radial Pisces, gen. & sp. indet. direction. Maximum length. width and Beside vertebrates tolerable numbers of thickness are 27.8, 9.8 and 22 mm re- Decapoda. Myliapoda and Mollusca were spectively. found. The fauna above mentioned is Right dentary no. 1 (figs. 3a-3d). correlated with that of the Upper Kuzuu Bone good in preservation although formation and regarded to Late Pleisto- tips of anterior- and posterior parts cene in age. Hitherto no fossil giant slightly broken. Length as preserved salamander were found in Japan, so the +8.7 mm, height and length of dental discovery of it from the Pleistocene arch 54.5 and .1.7 mm; height and thick- formation in Shikoku is very significant ness at anterior end 9.4 and 5.6 mm re- from the palaeogeographical point of spectively. Fossa for angular large, view. long and concave in buccal side. Pleuro- dont teeth sit at ridge of bone; teeth crown lost. Root undeveloped, but tubes Description of dental pulp of thirty three in numbers, developed at dental arch. A cross Megalobatrachus japonicus (TEMMINCK) section of tube oval shaped, 1.5 mm in Plate 29, figures 1-8 long diameter and 0.7-1.0 mm in short diameter. Height of tube •€4 mm in Specimens :-A right parietal. a right median part ; interval between tubes 1- parasphenoid, three right dentary and 2 mm. The osseus tissue of tubes the three vertebrae, stored in the Geological same as that of dentary. Attached area Institute, Yokohama National University. of the tubes to the wall of dental arch Locality:—Shikimizu limestone quar- becomes narrower upwardly. ry, Karaiwadani. Hijikawa-mura, Kita- Right dentary no. 2 (figs. 4a, 4b). gun, Ehime Prefecture. A fragment of posterior part pre- Horizon :—Late Pleistocene; Shikimi- served. Bone as large as no. 1 ; height zu bed composed of yellowish brown and thickness at end of dental arch 14.3 brecciated clay (fissure deposits). and 5.4mmmm respectively ; length as pre- Description:-Right parietal (figs. la, served +50 mm and length of dental b). 1 arch +33.4 mm. Dental pulp tubes all Bone rather complete in preservation lost ; shallow fossae and low ridges run but marginal part a little broken. Joint- in alternation on dentary. ing borders with left parietal, right Right dentary no. 3 (figs. 5a, 5b). 423. Discovery of the Fossil Giant Salamander (Megalobatrachus) 199

A small fragment of dentary pre- wider than centrum. Anterior neural served at the area of maxillary foramen. canal crescent, convex upward, while Bone considerably worn. posterior canal more circular than anter- Three vertebrae preserved of pre- ior. Articulating surface of prezygapo- sacral and post third vertebra. physis elongate oval, much longer than Vertebra no. 1 (figs. 6a-6d). wide and relatively longer than that of

Bone lustred, considerably large and no. 1. Articulating surface of post-

thicker than the following two bones; zygapophysis ovate. Zygapophysial ridge ossification developed ; ventral side well developed and slightly concave in

thicker than dorsal side. Centrum am- dorsal view. Right pre- and postzygapo-

phicoelous. longer than high and hand- physis broken off. Neural arch provid- drum formed in general outline with ed with an elevated ridge-like median median constriction. Centrum 18.8 mm keel ; neural spine absent. long along median ventral line ; anterior Vertebra no. 3 (figs. 8a-8e)

glenoid cavity 11.5mm wide and 12.0mm Bone like no. 2. Transverse process, high, while posterior glenoid cavity 12.2 right prezygapophysis, left postzygapo- mm wide and 11.2 mm high. Glenoid physis and upper part of posterior glen- cavity oval, deep, unpierced and with oid cavity broken off. Length of centrum median foramen lying dorsally ; ventral 12.0 mm : distance between tip of left surface of glenoid cavity larger than prezygapophysis and tip of right post- dorsal one ; anterior median foramen zygapophysis 18.8mm ; width of posterior almost touches posterior one. Some glenoid cavity +7 mm. A foramen at

nervous foramen opened on ventral the posterior margin of neural arch surface of mid centrum. Right pre- fairly deep and triangular with longest

zygapophysis and right transverse ventral margin.

process broken off ; base of left trans- Remarks:-The individual numbers verse process preserved. Right half of of the giant salamander in question seem

neural broken. Prczygapophysis stout to be four in total ; at least one is smal-

and large. Zygapophysial ridge well ler sized and at least three are larger developed, concave in dorsal view, par- sized. The specimen stored in the Ueno ticularly at its posterior part. Articulat- National Science Museum is 1170 mm in

ing surface of prezygapophysis elongate total length and that of Ueno's collec- oval in shape, longer than wide,•€7•~6 tion is 380 mm in ditto : assuming from mm and directed anterio-lateralward. these specimens, the smaller one seems Vertebra no. 2 (figs. 7a-7e). to be about 500 mm long and larger ones Bone slightly smaller than no. 1 and about 900 mm long. This species has ossification insufficient. Distance from relatively longer vertebrae than the

tip of left prezygapophysis to tip of left recent species (figs. 9a-9d), and no other

postzygapophysis 16 mm. Anterior glen- clear distinction can be noticed between oid cavity higher than wide, 6.7 mm the two species. Thus the writers put

wide and 6.9 mm high ; posterior glenoid this species to a recent one. As the cavity wider than high, 7.4 mm wide existence of fossil species is established and 6.6 mm high. Centrum 12.2mm long, in Shikoku, it may also be possible to

neural canal 3.7 mm wide and 22 mm discover a recent species in Shikoku, high. Neural arch at the narrowest the writers think.

portion of zygapophysial ridges slightly Distribution of Megalobatrachus :-— 200 Tokio SHIKAMA; and Yosilikazu HASEGAWA

After I. SATO the recent species is known from Middle Honsyu and North References Kyusyu ; the Kirigamine, Suwa-gun, BLAIR. W. F.. A. P. BLAIR, P. BRODNORB,F. R. Nagano Prefecture (northern limit of CAGLE. G. A. MOORE (1957). Vertebrates distribution), the Nagara River and the of the United States, pp. 218-219. Upper Hida River, Gihu Pref., the Na- CUVIER, G. (1825), Recherches sur les osse- bari River, Mie- and Nara Pref., the mens fossiles, tom. 5, pt. 2. pp. 431-444. Upper Asahi- and the Takahashi Rivers, pl. 26. Okayama Pref., the Upper Yura River, DARLIXGTON, P. J. (1957). Zoogeography. Kyoto Pref., the Upper Ota River, Hiro- ISIIIEAWA, C. (1903), Natural History of shima Pref., the Toyooka River, Hyogo Giant Salamander. Jour. Zool. Japan, vol. 15, no. 172. pp. 59-62. Pref.. the Tenjin- and I-lino Rivers, ISHIKAWA\ J. (1935), On the giant salaman- Tottori Pref., the Eno River, Shimane der captured in Matsuyama City. Zool. Pref., the Nishiki River. Yamaguchi Mag. Japan. vol. 47. no. 564. p. 714. Pref. and the Yakukan River. Oita Pref. KABURAKI, T. (1932), Habits of the giant etc. Some questionable samples, known salamander (Megalobatrachus japonicas). from the suburbs of Matsuyama city Gifu Pref. Rep. Nat. Monum. Sun:., no. and Kagawa Pref. (ISHIKAWA. 1935), may 2. pp. 108-111. be supported by the fossil species. - (1938) , Habitats of the giant salamander Cryptobranchidae is distributed in the (Megalobatrachus japonicas). Rep. Nat. world as follows; recent species is in fonum. Surv.. no. 3, pp. 98-103. M Eastern Asia including Japan, Lower OKADA. Y. (1949). Illustrated Encyclopedia of the Fauna of Japan, rev. ed., p. 290. Pliocene one in Nebraska. North Ameri- SATO, I. (1943). Introduction of Japanese ca and Miocene-Upper Oligocene one in Urodela. Europe. It may be said that Cryptobran- SILuOLD, P. F. (1842-47), Fauna Japonica. no. chidae migrated in geological ages from 3. Mammalia et Reptilia, pp. 127-135. pl. Europe to Eastern Asia. 6-8.

Explanation of Plate 29

Megcalobairaclms japonicas (TEM.)

Fig. 1. A part of right parietal. •~ 1. a, ventral side: b, dorsal side.

Fig. 2. A part of right parasphenoid, •~1. a, ventral side; b. dorsal side. Fig. 3. Right dentary. a. buccal side, •~1; b, lingual side, •~1; c. upper side, •~1.95; d, lingual

side, •~ 1.95.

Fig. 4. A part of right dentary, •~ 1. a, buccal side; b, lingual side. Fig. 5. A part of right dentary, •~1. a, buccal side: b. lingual side.

Fig. 6. Vertebra no. 1, •~1.9. a, dorsal side; b, ventral side; c, left side d. posterior side. Fig. 7. Vertebra no. 2.•~ 2. a, dorsal side; b, ventral side; c, left side; d, right side; e. an-

terior side.

Fig. S. Vertebra no. 3, •~2. a, dorsal side : b, ventral side; c. right side ; d, anterior side ; e,

posterior side. Fig. 9. Twentieth vertebra of recent specimen (Ueno's coll.), •~1.7. a, dorsal side; b, ventral

side ; c, anterior side; d, right side. SHIKAMA and HASEGAWA : Megalobatrachus Plate 29

3a 4 a 5a

3b 4b 5h

1 a 1 b 3d

2a 2b

6c 7c

8c 7b 7c

7a 9d 9b 7e

8 b

8a 6d 9c 8d 8 e

TAKAGT and HASEGAWA photo.