Family Puzosiidae from Hokkaido and Saghalien : Studies on the Cretaceous Ammonoidea from Hokkaido and Saghalien-V
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九州大学学術情報リポジトリ Kyushu University Institutional Repository Family Puzosiidae from Hokkaido and Saghalien : Studies on the Cretaceous Ammonoidea from Hokkaido and Saghalien-V Matsumoto, Tatsuro Faculty of Sciences, Kyushu University https://doi.org/10.5109/1524119 出版情報:九州大學理學部紀要 : Series D, Geology. 5 (2), pp.69-118, 1954-10-30. 九州大学理学部 バージョン: 権利関係: Mem, Fac. Sci,, Kyushu Univ,, Ser. D, Geology, Vol. V, No.2, PP.69-118, text・figs.1-6, table 1, plates 9-23,0ctober 1954 Family Puzosiidae from Hokkaido and Saghalien (Studies on the Cretaceous Ammonoidea from Hokkaido and Saghalien-V) By Tatsllro MATSUMOTO Introduction There are a number of forms referable to the Desmocerataceae in the Cre・ taceous deposits of Hokkaido and Saghalien. They are grouped in four families, Desmoceratidae, Puzosiidae, Kossmaticeratidae and Pachydiscidae. Some of the important members of the 6rst and last groups have been described in Iny recent paper(Appendix勿T. M.(Editor)1954). I treat here the second group. Although it would be desirable to give a de丘nition of the‘‘Family Puzosiidae”, there are certain unsettled questions relating to the extent and status of that group, so that I shall not discuss the matter at length here. However we have a series of forms which constitute a fairly easily recognizable natural group. The main purpose of this paper is to describe them systematically. In connexion with the description of our material some necessary remarks on foreign specimens will be included. In aconcluding chapter I shall give my preliminary view on the‘‘family”. The material which I have studied is mainly my own collection which was obtained in connexion with my stratigraphical work. The specimens are preserved partly in the Geological Institute, University of Tokyo(GT.)and partly in the Department of Geology, Kyushu University(GK.). As to the localities, horizons and stratigraphical problems readers are requested to refer to the previous papers(T.M. 1942-43and also T. M.(Editor)1954). I have fort皿ately been able to exarnine fully the original material of JIMBo(1894), YABE(1909)and KAwADA(1929)in the Univer・ sity of Tokyo. Some of the collections in tbe Department of Geology&Mineralogy, Hokkaido University and in Hokkaido Mineral Resources Survey(‘Chikashigen- Chosajo’), Sapporo have also been examined. After I had prepared a draft of this paper and photographs of our specimens I visited London(1953-54)and had an opportunity to observe specimens which are preserved in the British Museum(Natural History), Geological Survey& Museum of Great Britain and Mr. WRIGIIT’s collection. 70 T.Matsumoto Systematic Description Order Ammonoidea Superfamily Desmocerataceae Family Puzosiidae SpATII,1922 Genus Pμ208『αBAYLE,]878 1ン2りθ sρθoゴθs: ノ1〃2〃20〃カθs s〃妙Zα〃z〃α∫%s ScHLUTER, 1871 (=ノ1〃2〃20ηξ’θsカ10κ〃10∫〃5 BAYLE,1878,κoκSowERBY,1827). Gθκ〃ゴoD似g〃os£sごDiscoidal and rather evolute shell, consisting of many whorls which are compressed and elliptical in cross section and have an arched venter. Umbilicus of moderate size(30-40%of diameter)surrounded by a perpendicular wa11 with a subangular umbilical shoulder. Periodic, more or less flexiradiate, con・ strictions showing a forward projection on crossing venter. The ventral part of the whorls is ornamented with subcostae or fine costae which run nearly parallel to constrictions. The inner part of the flanks is almost smooth. Suture・lines in early stage of growth are similar to those of immatureルZε膓o〃oグ㌘s and in later stage of growth have a large and asymmetrically tri丘d L, unusua11y small U1,0blique or recurved U2 and remarkably descending elements of subdivided U3(=S). Rθ勿oグんs:The generic name was proposed by BAYLE(1878, explanation of pls. xlv and xlvi)without description of diagnosis. Of the three species figured by BAYLE as 1)〃20sゴα,ρ1耽〃膓α如was selected by H. DouvlLL丘(1879, p.91)as type. BAYLE’s 6gure of‘‘ヵ1α〃〃1α如”shows that he interpreted that species too widely and in fact his figure represents a species previously described by ScHLUTER (1871, P.4, P1. ii, 五gs.5-7)as/1〃2〃20κ力杉s sμbρ1α〃〃Zα∫〃s. There is therefore a case for regarding ρ膓α〃〃α’〃sSowERBY as debarred from selection as type species on the grounds that it was not one of BAYLE’s syntypes, but the question requires a decision by the Inter・ national Commission on Zoological Nomenclature苦. For the time being I fo110w Dr. SPATH’s interpretation (1923, P.42). The genus varies to some extent in compression and involution of whorls and also in curvature and strength of the constrictions;the features vary with growth and are modi6ed by condition of preservation. Therefore careful comparison at each growth.stage is necessary for the precise speci6c identi丘cation, while in too many cases only sma11, presumably immature specimens have been treated. However in the present state of our knowledge the genus seems to be divided into two subgroups, which are defined here as subgenera. Subgenus P〃20sグα(s. s.) D飢g%osεs:The outer whorl of the fu11-grown stage is essentia11y similar to the inner whorls but with obsolescent ornamentation. *Mr. C. W. WRIGHT proposes to refer the question to the Commission(personal communica・ tion, May,1953). Family Puzosiidae from Hokkaido and Saghalien 71 Subgenus Anapuzosia, nov. (ex MATsuMoTo,1938, MS.κo勿.〃〃4.) 乃φθ功θ6ゴεs: 1)〃205εαb〃ε〃o吻〃汐γαANDERsoN,1938. D飢gκosどs:The adult body chamber is ornamented with periodic, flared or tuberculated, strong ribs of little or no Hexuosity. About a half century ago Professor JAcoB, who examined carefully the change of characters at different growth-stages, described some interesting specimens with a peculiar ornamentation on the large adult body chamber under the speci6c name P〃20sξα勿αyoガαηα(JAcoB,1908, P.38, pl. vi,丘gs.1-4)and remarked that P〃20s化 がo〃〃α’αfrom Basses・Alpes, which is as large as his〃2⑳oグ切伽, never shows such astrong ornamentation. P〃20s∫αs〃bμα〃〃1α加(ScHLihER), the type species of Pμ20sゴo, is represellted also by fairly Iarge specimens, one of which exceeds over 300mm. in diameter(Sc肌6TER,1871, P.5). P〃20sゴαo磁ε〃sゴs KossMAT, which is closely allied to 1元s〃bがo〃〃σ∫α, reaches again to a very large size, being 285 rnm. in one example. However neither author observed in these large specimens of Pz’20sらthe particular ornament of JAcoB’s 〃2¢yoガα〃α. Fortunately I have been able to study a large specimen of P2420sどαfrom the Cenornanian of England, about 20cm・. indiameter(in GRIMsDAI,E Co1L Brit. Mus.(Nat. Hist.), without reg. no. but with GRIMsDAI,E’s no. 1551).Although it is water worn and still septate near its preserved last part, it shows normal ribbing of s励♪1α捌1α∫α・type on the venter and there is no trace of periodic, flared ribs. Our four species of Pκ205飢, described below, includes fairly large specimens of 200mln. or over in diameters but they never show strong periodic ribs, while som、e of our Puzosiids of later date, described in later pages under 〃吻bo『τ〃αs, do have that peculiar ornament on the adult body chmber. Unfortu・ nately I have failed to discover皿mistakable examples of A〃⑳〃20sどαfrom Hok・ kaido and Saghalien. However in the Albian(UpPer Horsetown group)of California there is another interesting example of Aμαρμ20sゴα, P. b∂4ω20砂θ川z6夕αANDERsoN (1938, p.185,p1.41,丘gs.1,2;?pL 40, fig.3), whose large outer whor1, about 160 mm. in diameter, has strong Periodic ribs, although without the pripheral tubercles of JAcoB’s〃2⑳oグ『⑫α. I designate here 1三力〃εκσ砂θη彦〃グσANDERsoN as the type species of∠伽ψμzosどo, since the specimens of JAcoB’s勿4yoタゴα伽are nomenclatorially doubtfuL苦 * Recent authors in France(FABRE,1940;BREIsTRoFFER 1936,1947)seem to have made it clear that d’ORBIGNY,s type of幼のo吻批came from the Cenomanian and the species could range down to the Albian, while JAcoB,s precise stratigraphic work (1907,1908)tells us that his只. 伽夕o加姻is rather common in the Lower to Middle Albian and is replaced by P.ヵ1ακ〃~鋤・ sκ地1αμ〃!α彪in the UpPer Albian and Cenomanian. JAcol3 recorded the occurrence of his Iarge 別のo酩ηαin the 4εη’αZμ8・zone. BRElsTRoFFER(1936, iηBEsAIRIE)regarded the small specimen of JAcoB’s〃2のoγ∫o%α(1908, P1. vi, fig.1)as a variety (boη〃21〃り of P〃20s紐4舵刀s’θ4存PARoNA &BoNARELLI. Thus the question remains whether JAcoB,s large別α夕o夕i醐αis identical with ・4〃2〃20痂’θs〃2⑳o万α〃od’ORBIGNY, P砿osω4%ηs’θ4ガPARoNA&BoNARELLI or otherwise. 72 T.Matsumoto Thus the distinctness of、肋ψ〃20s’αfrom Pμ20sゴo(s. s.)is justified as far as the well preserved specimens are concerned. However the inner whorls of the two groups are essentia11y similar and the special ornament of∠4〃O〃20s『αdid not affect the immature she11. There my be some distinction even in the immature shells, but I have failed to find good criteria. Prof. JAcoB and other authors remarked that」P.沈¢yoプZ碗σis less flattened than 1元がα〃〃1αZα(-s%bヵ1α%〃α∫のand in the former the lateral lobe(L)is regularly tri6d and somewhat deeper than E while in the latter it is distinctly asymmetric and much deeper than E. P. bκε〃卿θηωγαANDERsoN is also round whorled and has the suture of‘乃砺〃2α〃『・type’. The whorl shape however changes with growth and in different species. For instance I fortunately had an opportunity to observe a number of English specimens belonging to P. s加ヵεZ SpATH, which is said by many authors fairly sirnilar to P. 〃2の70夕ω〃α(d’ORBIGNY). In this species the whorl is as high as broad and rounded in section at diameters over 50mm. but is sometimes higher than broad and rather flattened at diameters below 40mm or so.(JAcoB’s immature specimen‘zη4yo夕ら〃o’ (1908,pl. vi, fig.1a, b) belongs rather to the latter category.) Indeed 1三 s〃αカθξ might belong to∠肋4餌20sξα, but the