A Middle Ordovician conodont faunule from the ...

A Middle Ordovician conodont faunule from the Tetagouche Group, Camel Back Mountain, New Brunswick D. J. KENNEDY Depmrtment q f Geology, Colora~IoCollrgr, Colorcldo Springs, C O . , U . S . A .80903

Can. J. Earth Sci. Downloaded from www.nrcresearchpress.com by UNIV VICTORIA on 04/07/14 For personal use only.

C. R. BARNES Ileparrmerrr uf Eurrh Sciences, University o f Waterloo, CY~lt~rloo, Ont., Canada hT2L3G 1 AND

T. T. UYENO Geological Survey ofcanada, 3303 33rd St. AT.W . , Calgary, Alta., C a n c ~ dT2L ~ ~2A7 Received August 1 1 , 1978 Revision accepted November 3, 1978

'She 'Tetagouche Group is a 10000 ni geosynclinal sequence of slates, greywackes, rhyolite tuffs, and greenstones underlying parts of northern New Brunswick. It hosts the well-known stratabound massive sulphide deposits of the Bathurst-Newcastle mining area Few fossils have been found in the group and its age is poorly known. More than 890 collodonts have been recovered from a locality near Carnel Back Mountain in the Metahasalt unit. Corlocerodontus? lucrimosu~and Protopcrnderodus liripipus are described as new species. The faunule contains Zone species indicative of the Yrioniotli,~alobatus Subzone of the Amorpllo,qnmthus tvaert~nsi.~ and is the first record of the subzone in North America. The subzone equates with the middle Caradocian (approxiniate8y the Soudleyan Stage) or late Wildernessian Stage of the Middle Ordovician Epoch. During this interv:il the Proto-Atlantic Ocean is considered to have been undergoing closure, hence recent interpretations that regard the Metabasalt tlnit as forming during an earlier phase of opening must be reexamined. Le groupe de Tetagotlche est ilne sequence geosynclinale de 10000 m comprenant des ardoises, des grauwackes, des tufs rhyolitiques et des roches vertes qu'on retrouve en profondeur en plusieurs endroits du nord du Nouveau-Brunswick. I,e groupe renferme les dkpbts stratiformnes de sulfures massifs de la region miniere de Bathurst-Newcastle. On a trouve peu de fossiles dans le groupe et son Age est ma1 etahli. On a trouve au-delh de 890 conodontes dans une localite pres de Canlel Back Mountain dans I'unite de metabasalte. On decrit Coeloc~rodontus? lnc~ri~nosus et Protopanderodu.~liripipus comme de nouvelles especes. I.,a faunule comprend des especes indicatrices de la sous-zone Prioniod~tsalobatus de la zone Amorplzognathus roc~erensis et c'est la premiere occurrence de cette sous-zone en Anlerique du Nord. I,a sous-zone est en correlation avec le Caradocien moyen (appr-osimativement I'etage de Soudley) o u I'etage du Wilderness superieur de I'Ordovicien moyen. Durant cet intervalle, on pense que I'ocean protoAtlanaique s'est referme et ainsi on doit reexaminer les interpretations recentes qui regardent I'unite de metabasalte comnie s'etant forrne durant une phase plus ancienne d'ouverture. [Traduit par lejournal] Can. J. Earth Sci., 16, 540-551 (1979)

Introduction The northern part of the Miramichi Highlands of northern New Brunswick is underlain by Ordovician, Silurian, and Devonian volcanic and sedimentary rocks. The strata are strongly folded and intruded by Devonian granites and some basic rocks. The rocks of Ordovician age belong to the Tetagouche Group and contain the famed zinclead-copper deposit s of the Bat hurst-Newcas tle mining area. A recent detailed study of the Tetagouche Group of the Bathurst region by Skinner (1974) provided a three-fold division of the group. In ascending order the divisions are Sedimentary unit, Metabasalt unit, and Rhyolitic unit. The total thickness of the

group is thought to be in the order of lOOOOm (Skinner 1974). However, a sparsity of outcrops, marker beds, fossils, sedimentary (way-up) structures, combined with complex structure, result in poorly known stratigraphy and uncertain thickness. The Tetrigouche Group consists of slate, greywacke, rhyolite tuff, and greenstone. Polyphase deformation has produced a greenschist facies (locally amphibolite facies) of metamorphism for much of the group (Williams c't ul. 1972, p. 221). These authors noted (y. 213) that although Middle Ordovician fossils have been recorded from parts of the Tetagouche Group that are less deformed, much of the group is more complexly and inten-

0008-4077/79/030540-12$(1H .00/0 @l979 National Research Council of CanadaIConseil national de recherches du Canada

KENNEDY ET AL.


sively folded and may represent older deposits involved in an earlier deformation, of possibly late C~iinbrianage. The Tetagouche Group is regarded as a geosynclinal sequence associated with an island arc (the Tetagouche Arc) that lay to the south of another island arc (the Oliverian Arc) located in Gaspk, Quebec (Bird and Dewey 1970, pp. 1031-1060; Skinner 1974. pp. 45-46; Rast and Stringer 1974). The exact nature of the units within the 'Tetagouche Group with respect to the island arc model is currently in dispute. In particular, there is disagreement on whet her the graptolite-bearing sedimentary rocks postdate (Skinner 1974; McBride 1976) or predate (Davies et ui. 1973) the volcanic rocks. Of the latter rocks, the Metabasalt unit of Skinner (1974) has been interpreted by Whitehead and Goodfellow (1978, p. 216) as an ocean floor basalt sequence "formed as a result of rifting at the mid-oceanic ridge which was associated with the opening of the Proto-Atlantic". McBride (1976, p. 481) proposed that the "Tetagouche volcanic rocks represent an islandarc system built adjacent to a subduction zone during Cambrian times on the northwestern edge of the stable craton now represented by the Avalon Platform of Newfoundland and the Caledonian Belt of Southern New Brunswick". Both these recent interpretations are difficult to reconcile with the limited paleontological data. Rast and Stringer (1974, p. 17) reported the occurrence of Arenig fossils near the top of the lower unit of the Tetagouche Group. The conodont data presented herein show that part of the Metabasalt unit is of early Caradocian age. The graptolites from the Sedimentary unit (W. T. Dean irz Skinner 1974, p. 43) provide a Caradocian age, similar to o r somewhat younger than the conodonts from the underlying Metabasalt unit. The latter two units thus probably formed during the period of closure, I-ather than opening, of the Proto-Atlantic Ocean. A resolution of the complex stratigraphic and structural problems will be assisted by improved paleontologic control. Fossils have been found in each of the map units: graptolites in the Sedimentary unit, trilobites, and now conodonts, in the Metabasalt unit. and crinoids in the Rhyolitic unit (Skinner 1974, p. 43-44). The graptolites suggest a Caradocian age, about Clirnncograptus ~iilsoni Zone or Bicmrzograptus clingnni Zone. The crinoid data provided no precise age. The trilobites were collected in 1969 and 1970 by H. Melmstaedt and W. T. Dean of the Geological Survey of Canada. These came from "a lenticular

541

bed of greyish-white limestone intercalated with greenstone of the Metabasalt unit at a point mile east of Eighteen Mile Brook and 13miles north of the summit of Camel Back Mountain, 35 miles west-southwest of Bathurst." (W. T . Dean in Skinner 1974, p. 43). The preliminary trilobite data suggested a Porterfieldian age. Some of the limestone samples that were collected for trilobites, were processed for conodonts. A faunule of 894 specimens was recovered. Although black, opaque, and slightly etched and fractured, the specimens are well preserved considering the regional deformation. From a prelirninary examination, Uyeno (in Skinner 1974, p. 43) reported that "the faunule. previously unreported from the North American continent, is of Baltoscandian aspect and belongs t o the Ansorphogrzrrthu,~tvnererzsis Zone, Prioniodr~saiobatus Subzone of Bergstrom (1971)" and thus of middle Caradocian age (Fig. 1). The purpose of this present paper is to (a) describe the conodont faunule in detail; (b) provide some taxonomic revision of conodonts from the Priorliodus alohntr~sSubzone and document its presence in North America: and ( c ) indicate that further collections for conodonts may be fruitful and could eventually allow better resolution of the complex stratigraphic and structural problenls of the region. Conodont Fauna Approximately 6 kg of limestone from the Camel Back Mountain locality yielded a total of 894 identifiable conodonts (Table 1). The conodonts are typical of the North Atlantic Province for which a detailed zonation has been established (Bergstrom 1971). The faunule is of low diversity, comprising five multielement species and five form species. It is dominated numerically by four multielement species: Periodon cf. P. ac.ulentus Hadding, Arrzorphogrzuflzus tvrrerensis Bergstrom, Prioniod~rs aiobatr4s BergstrGm, and Protopanderodus liripipus n. sp. The last three of these species in the fauna enable correlation with sequences elsewhere. P . celobarus is the inost significant species as it is restricted to the P. r~iobatusSubzone of the Amorphognathus tvaerensis Zone in the Dalby Iimestone, Sweden (Bergstrom 1971, p. 101). Viira (1967, table 1) records the presence of the amorphognathiform element in Stages CII (Kukruse) and CIII (Idavere) in Estonia. Bergstrom (1971, p. 106) placed the boundary between the Idavere and the overlying Johvi Stage within the P. alobarus Subzone.


TABLE1. Conodonts collected from the haetabasalt unit, Tctagouche Group, at Camel Back Mountain, New Brunswick " A c o ~ ~ ~mutatus ~ s " (Branson and Mehlb "Acokfirs" sa'i77iirrris Rhodes s.f. Amorphognuthus tvcrererzsis Bergstr~m arnorphognathiform (partly complete) estimated from fragments ambalodiform dextral sinistral *ligonodiniform Coeloceror~ontus?lucrirno~usn.sp. s.f. "Drepanoilus" altiyes Henningsmoen s.f. "l'onderor~u.~"' ~it?zilarisRhodes Pcriodoi? aculeatu~Hadding transition serizs (total) cordylodifortn ligonodiniform cladognathiform hibbardclliform prioniodiniform tortiliform falodiform acideatus-type grandis-type Prioniodlrs alobatu~KergstrBn~ prioniodiform amc~rp3hsgnathiform(complete) broken platforn~s belodiforrn hi bbardellifosm tetrapsioniodiform oistodiform ~3oto~~ai1dc~ro~ius Iiripipus a s p . symn~etricaland sligl~tlyasymmetrical markedly asymmetrical scandodiform Str~chanogncrtiiusptrruus Rhodes s.fe

UPPER SUBZONE

LQWER SUBZQNE FIG.1. Conodont zones and sub~onesof the Elalmdeilian and early Caradociati (Hergstriim 1971). 'I'he Camel Back fziun~ale belongs to thc I'rioniod~4~ alohut~i.> S u b ~ s n e(asterisk).

America, particularly the Porterfield Stage of the Virginia Appalachians. Bergstrom (197 1, fig. 11) has shown that the range of the type Porterfieldian Stage overlaps considerably with the type Wildernessian Stage. Systematic Yaksntology The prefix GSC refers to specimens deposited in the type collection of the Geological Survey of Canada, Ottawa. All species names are used in the sense of multielement species unless qualified by s.f., sensrrformo. Generic names in quotes I-eferto Total 894 traditional form genus assignments. For description, elements are oriented with the oral margin *NOTF:Other rarniform elements are illdistinguishable from those of Prioiriorlus alobatus. horizontal. No significant new con~mentsare possible about Detailed cc)rrelation with the Norwegian Chasmops Shale and Limestone cannot be effected as the following taxa: Warnar. (1966) did not report any Yrionic~dus "Acod~r,~" I I Z U ~ ( ~ ~(Brarason MS and Mehl, 1933) s .f. : species. Bergstriim (1971. p. 104) suggested a broad not illustrated. "Ac*odus" similaris Rhodes, 1955 s.f.: plate 1421, correlatioia of the upper part of A . ~ ~ ~ n e r e nZone sks with the Lower Chasmops Shale and Lower Chas- 22). "Drepartodus" uPtipes Henningsiraoen, 1948 s .f. : mops Liirae st one. 'The Camel Back faunelle can therefore be dated not illustrated. 6Pancierodus"sinziPari.s (Rhodes, 1953) s .fa: not as belonging to the Prioniodus uloKatl~sSubzone of Zone (Fig. 1). The illtistrated. the Amorphognukhus tvaer~n,c.is stibzone equates with the middle Caradocian, approximately the Soudleyan Stage, or the late Genus Arnorphogrzathus Branson and Mehl, 1933 Wildernessian Stage of the Middle Ordovician. Emended Bergstrom and Sweet 1966 and This is the first reported occurrence of the subzone Bergstrom 1971 in North America. The conodont evidence is in general agreement with the preliminary trilobite Tjjpt. species : Amcsrphognathu,~orsdocicicus Branson and Mehl, 1933 data noted by W. T. Dean (in Skinner 1974, p. 43). which showed that the trilobites have much in Arnorphognathus tvuerc.nsis Bergstriim, 1962 Plate 1, figs. 25-27, 29 common with assemblages from eastern North

KENNEDY ET AL.

543

Genus Coeloc.c)rodontus Et hington, 1959 Arnorphognatlzus tvaerensis Bergstriin 1962, pp. 36-37, plate 4(7-10); Bergstrom, 1971, pp. Tvpe s p ~ ~ *:i eCoelo~~erodontirs s trigonius E t hing135-136, plate 2 (10 only; 11 = holodontiform eleton, 1959 ment): Lindstrom, 1977, pp. 47-49, plate 2 (1- 12) C'oc~locerodontr~s ? lac-ritnosus n. s p. s .f. (contains merltielement synonymy to date). Plate 1, figs. 20,23 Can. J. Earth Sci. Downloaded from www.nrcresearchpress.com by UNIV VICTORIA on 04/07/14 For personal use only.

Kc)rncirks The one partly complete amorphognathiform element differs markedly from most illustrated amorphognathiform elements but is very similar to the specimen illustrated by Viira (1974, plate 7(24)). The brokela specimen lies within the range of variation of A. tvneretzsis (Lindstrom 1977; S. M. Bergstriim, personal communication, 1978). Many broken processes are present and they appear to be from amorphognathiform elements of this species. The arnbalodiform elements, which presumably belong to this apparatus, are similar to the two unpaired am balodiform elements of A rnorphogtlutkzlrs t~:uerc~rt,ri.s Bergstrom s. f., i.e. Arnbulodirs ti-icengulciris slrccic.us Bergstrorn s.f. and A. t . erratic-us Bergstriim s.f. The denticles on the anterior process are not as large as those in specimens illustrated by Bergstriim (1962, plate 3 (11-17)). The Camel Back Mountain arnbalodiform elements are closely comparable to elements of A. t . serecicers S ~ ~ S Viira I A (1974). It is notable that Viira(1970, table I) recorded her three form subspecies of Arnorphognutlzrrs ordovic.ic~rsfrom Stages CII (Kukr-use) and CIII (Idavere) in Estonia and no other amorphognathiforna elements had a similar range. A. t . sue(-icus and A. t. erraticus sensu Vih-a, 1970 (= A . t . suecicus sensu Viira. 1974)have identical ranges, i.e. Stages CII and CIII and no other ambalodiforin elements were recorded from these two stages. Of the I-amiform transition series, only one specimen of the ligonodiniform element was found, though others may lack the denticillation on the anticusp and be indistinguishable from the belodlform elements of B. rilobat14s. The other ramiform elements could not be distinguished from homologous elements of Y. alobeltus and no holodontiform elements were found. Viira (1970) also recorded Ligonodinu delic-atci s. f. from Stages CII to CIII and Stages E to FII. Such a distribution suggests similar ligonodiniform elements in two or more apparatuses of Amoi-phognuth~rs. Two form species, Tetrcprisniocius asymmetricus Bergstrom s.f. and T. cf. T. superhus (Rhodes) s.f., and one hi bbardell iform species Rourzdyu inc-litznta (Rhodes) s .f. were also identified by Viira (1970) from strata of Stages CII and CIII. Types Hypotypes: GSC60653-60656

Ilicmgtzosis Simple cone has low, sharp anterior and posterior costae, a suboval cross section with a height to length ratio of about 1:3 to 114and a suberect to proclined cusp. Ile,vcriptic~tzof Holotyye Element is a simple, unornamented cone. Oralposterior margin curves evenly through a broad arc and the distal end of the cusp is suberect. Oralposterior and aboral-anterior edges are sharp. One side is almost flat and the other is smooth and broadly rounded, with the maximum curvature slightly posterior and aboral to the median position. Basal rim flares slightly. Basal margin is straight; basal edge is sharp; oral-basal angle and aboralbasal angles are each about 85 degrees; Iacrymiform basal outline is slightly irregular. Basal cavity extends to the tip of the cusp and the walls are extremely thin. V uria t ion Elements vary from symmetrical to slightly twisted out of the oral-aboral plane. Basal outline varies from biconvex to suboval to lachrymiform. Rate of tapering of proximal portion of element relative to distal portion is variable (compare figs. 20 and 23 on Plate 1). A slight swellingjust in front of the basal edge may be present though the walls are not thickened (fig. 20 on Plate 1). Postero-oral and antero-oral edges vary from sharp (fig. 23 on Plate 1) to sharply costate (fig. 20 on Plate 1). Cusp varies from suberect to proclined at about 45 degrees. Etymology Lucrirnu, Latin. tear; Iachrymiform, tear-drop shaped. Retncirks The species is believed to have had a monoelemental apparatus; however, because of the few specimens available a multielement species is not erected at this time. 'I'he elements differ from our specimens of C . digonius Sweet and Rergstriim from the Lincolnshire Formation and illustrations of the type specimens from the Pr-att Ferry (Sweet and Bergstom 1962) in the ratios of their length, width, and height (elements of C . '? lac-rimcasusare relatively wider and shorter) and in the inclination of the cusp. A number of simple cones with deep basal

544

C A N . .I.EARTH SCI. VOL. 16, 1979

cavities and thin walls are present in Ordovician strata. Their taxonomic relationships are poorly understood and we are not convinced that this species is closely related to the type species, hence the query. Can. J. Earth Sci. Downloaded from www.nrcresearchpress.com by UNIV VICTORIA on 04/07/14 For personal use only.

Types Molotype: GSC60658 Paratypes: GSC160657,60659-60663 Genus Yer.iodon Hadding, 1913 Emended Bergstrom and Sweet, 1966

Tvpc. spc.c.ic~s:Yc~riodo~l cl(~lleatusHadd ing, 1913 Periodon cf. Y . crc-uiec~t~~~ Hadding, 1913 Plate 1, fig. 1-8. 35

Multic.!cnlent sprc.ies sf. Periodo/~~lc-zr!e(rt~ls Madding. Bergstriim and Sweet 1966, p. 363; Barnes and Poplawski 1973. pp. 780-781, plate 5 (15- 1$a) (contains synonymies for constituent elements of the assemblage to date; non ()i,st(?dlkshiiongclt~l,~ Harris, 1962; non Eyfulodrrs hrpr>isHarris, 1962); Be]-gstriim ct al. 1974, plate 1 (4-6), tables 6, 10; Landing 1976, p. 636, plate 3 (3-6, 14); Repetski and Ethitigton 1977, table 2, plate 1 (16-18, 20, 22, 24); Fihraeus and Nowlan 1978. p. 462, plate 3 (7-10, 13) (only), text-figure 5 (synonymy to 1977).

Kcmcrrks The nomenclature for the elements of the apparatuses of Pc.riodor7 has evolved subtly in recent publications. P. acrrleutl4s contains a periodoniform transition series with cordylodifurm, cladog-

nat hiform, ligonodiniform and hibbardelliform elements (aft;r Lindstriim 19641, prioiiiodiniform (= Ozarko~iinumac.rodentatus Graves and Ellison), tol-tiiiform (= Ligonodiilcr tortiiis Sweet atid Bergstriim) and falodiforin (= Oisto~irisprodci~tutus Graves and Ellison). 'Phe tortiliform element has been termed "ligonodinifor-m" or "oulodiform" by many workers, but we follow Kcpetski and Ethington (1977, table 2) to avoid confusion with the ligorlodiniform element of the transition series. The differences between the periodonifr~rmelenients of Y . grandis Ethington and Y . acmulcutu.s have been noted by Bergstrom and Sweet (1966, p. 365), but the development of a rudimentary hindeodelloid denticulation inY. gratzcl'is and not in P. crcuiec~tu,~ has not been noted by previous workers. The variation present in the periodoniform elements is interpreted as intraspecific, although possibly more than one species is present. The prioniodinifol-m element is also variable. Some rare elements are almost bilaterally symmetrical with a flattened basal cavity and almost straight basal margin, i.e. ozarkodiniform. In profile, the anterior basal margin inay project dowiiwards through an angle of 90" with respect to the horizontal posterior basal margin; the average is about 60". I n plan view, elements vary from altnost straight to strongly curved, with the anterior process forming an angle of about 100° with respect to the posterior process. The anterior process varies from short, with a few denticles, to elongated with up to five denticles. The number of denticles on the posterior process varies from three to six.

P L ~ T1.F All specimen\ arc illustrated in side view, except for figs. 25, 26, and 35, which are in oral view. Type3 ancl figured specimens are depo4ted with the Geological Survey of Canada, Ottawa. FIGS. 1-8, 35. Periodon cf. P . ac.~lieutusHadding 1913. (1. 4-6) Periodc.rniforna transition series: (1) Hibbardelliforn~ element, GSC 60664, x 89. (4) Cladognathiform element, GSC 60667, x 42. (5) Cordylodiform elernent, GSC 60668, x 60. (6) I~igonodinifornaelement, GSC 60669, x 48. (2, 7, 8) Oistodiform elements: (2) ctculrutus-type, GSC 60665, x 50. (7) rlculeatr1~-type,GSC 60670, x 47. (8) grntzdi.5-type, GSC 60671, x 100. (3) 'Tortilifornm element, GSC 60666, x 52. (35) Prioniod~niformelement, GSC 60672, x 53. FIC;~. 9- 19. Protcjpatzderodr~.\liripipu~n. sp. (14) is holotype; others are pardtypes. (9-1 1. 13, 14, 16, 17) Protopanderoclifemn transition series: (9) Symmetrical elernent. GSC 60680, specimen lo5t. (13) Symmetrical element GSC 60684, x 46. (13) Symmetrical element, GSC 60685, x 47. (16) Slightly asymmetrical element GSC 60687. x 42. (10, 11) Markedly asymmetrical element GSC 60681, x 42ancl GSC 60682, x 42. (17) Markedly asymmetrical element GSC 60688, x 40. (12, 15, 18, 19) Sc:tndodiform elements. (12) GSC 60683, x 46. (15) GSC 60686, x 50. ( I 8) GSC 60689, specimen lost. (19) GSC 60690, x 51. FIGS.20, 23. ('oeboc~crodontus'?leitritnosus 11. bp. 4.f. (20) GSC 60657 x 38, (paratype). (23) GSC 60658, x 55, (holotype). FIGS.21,22. "Acoclu~" ~in~il(iris Rkotles, 1955, 5.f. (21) GSC 6065 1, x 45. (22) GSC 60652, x 50. FIG.24. Streic.hanognr~thu.spnrl~usRhodes, 1955, 5.f. GSC 60706, x 67. FIGS.25-27, 29. Arnorphognarhu.~tvaerensis Bergstriim, 1962. (25) Amorphognathiform elenaent, GSC 606.53, x 30. (26, 27) Ambalodiform elements. (26) upper view, GSC 60654, x 45. (27) inner view, GSC 60655, x 63. (29) L,igonodiniform element. GSC 60656, x 86. FIGS.28, 30-34, 36. Prioniodus rilc~batu~ Hergstrtjm. (28) Oistodiforn~element, GSC 60673, x 38. (30) Tetraprioniod~form element. GSG 60674, x 69. (31, 33) Relodiforrn elements. (31) GSC 60675, x 67. (33) GSC 60677, x 69. (32) Hibkardellifc~rn1 element GSC 00676, x 57. (34) Amunphognathiform eiement, inner view, GSC 60678, x 38. (36) Prioniodiforna element, inner view, GSC 60679, '.i 47.


KENNEDY ET AL.

545

546

CAW. J . EARTH SCI. V O t . 16. 1999


averaging four to five. The processes are of subequal length. A few specimens are almost identical to the prioniodiniform element of B.grcandis, which was illustrated by BergstrGm and Sweet (1966, plate 38 ( I , 2)). None are similar to the specimen illustrated by EtRingtsn (1959, pHate 41 (14)). The tortiliform elements are similar to previously illtlst~itedforms and they differ from the elements in P . flabeHbum Lindstr4Bm in possessing a more elongated posterior process and more highly developed anterior process. Most fi~lsdiform elements are comparable to those which have been placed previously in P. aclaie~&les (e,g. $el-pagfi 19'74, text-figure 14). However, about 10% of the falodiform elements are indistinguishable from those of P . gs-asadis and a few are morphologically transitional between the two species. Serpagli (1974, text-figure 14) presented a simplified monophyletic lineage of the falodgorm eIernents of P ~ r i o d ~ ~ ai.e. a , one species following another. Clearly this is an aver-simplification ;as falod20nn.n elements typical of P, aculentus and P . grandi,~ occur together in this sample, in the Dubuque Formation, Minnesota (Webers 1966) and the Ampyx to Upper Chasmc~psLimestone, Oslo region (Hamar 1966). Two interpretations are suggested to e x p l a i ~the joint occurrence s f the two species. Firstly, P. gr~srrdiscould have separated from P. acuieaaess in ;bout the middle ~ i d d l Ordovician e and both continued to coexist as separate species into the late Middle Ordovician with the filiodzorrn elements of P. grandis evolving more rapidly than the nonfiilodZorm elements, B. acubeatus appears to have become extinct Hate in the Middle Ordovician whereas P. grkirndis became extinct in the Late Ordovician Epoch. Secondly, one species could be represented at any one time, but undergoing gradualistic evolution with a shift in the dominant n~onpkologyin each of the element types. Our single sample and the limited data in the literature Qsnot enable a choice to be made. We Rave chosen, somewhat arbitrarily, to describe this Periodon complex as B. cf. B. acu%eudus.

Genus Prionisdus Pander, B 856 Erner~dedBergstrGm, 1968, 1971 Type ,qwcies :B r i o n i o d ~48egQ~i+t$ .~~ Pander, 1856 Ps-istniokfl~s sz%csg;Pkir8us Bergstr6m, 197 B Plate 1 , figs. 28,30-34, 36

L W l f l t i ~ E ~ species m~r~f Pricsniodus ajobupus Bergstr6mr51971, p. 146, plate 2 (4,5). Baltonicsdldsd~1oba81.b~ (Bergstre4r-n). Lind strQ5m1977, p. 65, plate 1 ( I , 2) (reillustration of BergstrCPm, B9"1 plate 2 (4,5>). Remarks The pl-oblern of the relationship between P s - i o ~ ~ i o dand u ~ Bnltdsniodus has been discussed by Fghraeus and Nawlan (1 978, p. 463). We have chosen to follow their judgment in the matter. The amorphognathiform element is usually braken at a constriction near the junction of the platform and the base of the cusp. Platforms are extremely variable in plan and mnge from narrow and elongate lachrymiferm (cf. halotype) to kroadl y lachrymifcorm, A lateral lobe is variably developed and is prominent in about a third of the specimens. The lobe and the platforms are generally subhorizonttil and rarely are inclined with dow nwiasd projecting lobe as in B. z.car.id~bi%is (e.g. BergstrGm 19'71, plate 2 (2)). Platform ledges are prominent. The angle between the anterior and posterior processes is muck greater in B. alobatus than in P. ul~ril~ b&djBi,~ Elements s f the transition series are difficult to distinguish from those of A . drh~verensisexcept for the ligonodiniform element. Oistodiforrn elements lack denticles along the antero-aboffal margin. ,5'.

1 ypus

Hypotypes r GSC 60673-60479. Genus Pp.otc~pas;(~$k.rod~~,~ Lindsti-(im, 1971 Type ,~pecies: Accsum tiodus s-ectus LindstrGm, 1355 Pro&c~pcindercpdars %ir.i12ipgss[s n . sp. Plate 1 , figs. 9- 19 Scnndnd#brr;~a~ % ~ J P E C M ~ Scandoga"64s unisbriaters Sweet and Bergstr6n-i. Mamar 1966, p. 74, piate 3 (1,7). '? Sea ndodfus ~ ~ S S ~ ' B B Z (Branson ~ ~ U B " ~ Sand hkhl). Serpagli 1967, pp. 94-95, plate 24 65,6).

Pro&c~p~611d~~rdsd$srr~? transition series ? Scolopodus:$ insc.u&ptus (Branson ;and Mehl). Serpagli 1967, pp. 97-88, plate 28 (1-4); non plate 28 (5,6>* " 6 S c o % ~ ~ IP, d usp. ~ 1cf* S ' * S.' & D ~ S C U % ~ P ~ ~ S ( B ~ ~ I B S O and Mekl). Bergstf-6m I97 1, p. 100, text-figure 4. Pl'otoparndjek~r'c~d~ds n. SP. ef. P . r'nsc.u!pbus (Branson and Mehl). Bergstr6rn and Carnes 1976, text-figure 2. S c o k ~ p o dIP. ~~ SP. cE. S. ipilscatdli>,~~t~~ (Bransow and

KENNEDY ET AIL.

Mehl) sctzsu Bergstrom. Repetski and Ethington 1977. table 2, plate 1 (12, 13). tlon Scolopodus itz,sculptu,s (Branson and Mehl). Hamar 1966, pp. 15- 16, plate 1 (18).

547

veloped secondary costa on one side, are rare. In these latter forms the secondary costa is usually developed only on the base. Ware slightly asymmetrical specimens have three costae on one side. 'The third costa originates on the base by bifurcation of the secondary costa. In most markedly asymmetrical specimens the single costa is well developed; in rare specimens it may be developed so poorly that the side is almost smooth. The cusp may vary from slightly pr-oclined to reclined at 45 degrees and may vary from almost straight to broadly arcuate. 'The anterior margin-basal margin junction varies from acute (70-80 degrees) to broadly rounded. The developn~entof the notch in symmetrical and slightly asymmetrical elerilents may be non-existent to faint (approximately 30%), slightly developed (45%) or well developed (25%). In markedly asymmetrical elements, the notch is less pronounced: non-existent to faint (60%), slightly developed (35%), well developed (5%). The tapered extension of the base varies from short to extremely long.


I1iugno.sis ofAppcrrcrtus Apparatus consists of scandodiform elements and a transition series of protopanderodiform elements. Transition series contains symmetrical and slightly asymmetrical elements with two costae on each side and markedly asymmetrical elements with two costae on one side and one on the other. All elements are characterized by posterior tapering of the base and most have posteriorly extended bases. Pn~ropatzderod$orm tt-ansitiot~series Desc-ription : Symlnetrical element (holotype) Oral margin is long and slightly convex. Oral edge is sharp. Oral margin curves evenly through a broad arc to form the posterior cusp margin. Anterior and posterior cusp edges are sharp. Proximally, the cusp is slightly proclined; distally it is slightly reclined. Cross section of the cusp is a modified rhombus with slightly concave faces. A Sc-andudifilrrrz rloment prominent sharp costa of moderate height occupies I)c-'scriptiotz Oral margin is long and slightly convex. Oral the median position on each side of the cusp. A edge is sharp and situated on the outer side of the second smaller costa is situated slightly posterior to base, which flares slightly on the inner side. Oral and parallel with the main costa. Groove separating the primary and secondary costae is moderately edge curves evenly through approximately 80 dedeep. On each side, both lateral costae descend grees to forn-Ithe posterior cusp edge. Anterior and from the cusp onto the base and curve slightly posterior cusp margins are broadly arcuate and posteriorly in a broad arc. The main costa merges cusp edges are sharp. Cusp is narrowly biconvex, into the basal edge; the secondary costa fades out erect, and the anterior portion is twisted inwards. on the base. Immediately anterior of the main Outer cusp face is smooth; inner face has a narrow costa-basal edge junction is a shallow notch. The groove which is parallel and close to the anterior basal profile tapers posteriorly. The posterior seg- cusp nrargin. Groove curves posteriorly as it dement of the basal margin rises to meet the oral scends onto the base and it fades out just short of margin in a sharply rounded point. In the region of the basal edge in a subhorizontal position. On the the antero-abor-a1corner, the lateral sides convei-ge base, the groove is flanked anteriorly by a short, low, narrow ridge and posteriorly by a short, broad to form a prominent keel. low ridge. Drscriptiorz: Slightly and markedly asymnletrical Basally, the anterior margin curves slightly poselements teriorly and the junction with the basal margin is Slightly asymmetrical elements have two costae rounded. Anterior segment of the basal margin is asymmetrically disposed on each side. Markedly horizontal. but near the junction with the groove it asymmetrical elements have two costae on one side rises to meet the oral margin at a sharply rounded and one on the other. point. Sides of the base taper anteriorly such that the antero-aboral corner is keel-like. Posteriorly, Vm-a'utiorlin yrotopuncierodiJ;~rmc~lenzt'uts the inner side flares moderately. Variation is considerable. Cross sections show continuous variation between symmetrical and Vat-icrtion slightly asymmetrical placement of the costae and Variation is similar to that in the protopanthe two groups cannot be separated easily. The derodiform elements. 'The basal portion of the anmarkedly asymmetrical forms can be separated terior margin varies from straight to evenly curved readily; forms transitional to the slightly asymmet- to the posterior. Straight anterior margins vary rical vrzriant. i.e. elements with a very poorly de- from vertical (with respect to the horizontal oral

548

CAN. J. EARTH SCI.


margin), to being directed posteriorly up to about 40 degrees from the vertical. In the former case, a flange is developed in the antero-basal corner. The basal margin is exti-emely v:ariable (see illustrations). In most specimens, the anterior segment is subhorizontal and the posterior segment rises to meet the oral margin. The angle formed between the posterior segment and the oral margin is more acute when the oral margin is elongated.

VOL..

16. 1979

the scandodiform element of P . liripipus. However, the specimen identified by Hamar (1966, plate 1 (18)) as Scolopodus varicostatus s.f. is from strata of the Middle Ampyx Limestone (Middle Llandeilian) and is referred to here as a protopanderodiform element of P. varic-ostatus.

( B ) Rcmt.rk,s. on the distinguishing jiwtures of' P. liripipus The elongate and pointed bases of elements of P . Etytnology liripipus are the most useful features to distinguish The liripipe fashion, which was common in the elements of the species from those of P . r-laric-os12th to 14th centuries, was characterized by the tatus and P. insculptus. elongation of sleeves, hats, and shoes. The liripipe It must be emphasized that identifications should toe referred to the elongated shoes, similar to the be based on more than just a few specimens for profile view of the protopanderodiform elements. some variaats of P. varicostntus (e.g. Bergstrom et From Latin. liripipilrm. ul. 1974, plate 1 (9)) are similar to a few elements of ( A )Remarks on tfzp appcrratzrs c.orrmpusition P. liripipus. The association of elements in the fauna from Sweet and Bergstrom (1962, p. 1248) were able to Camel Back Mountain, here interpreted as a mul- recognize three distinct groups (symnletrical , tielement species, P. liripiprrs, is similar to two slightly asymmetrical, and markedly asymmetrical) other associations suggested originally by in the protopanderodiform element of P . ~~czricosBergstrom and Sweet ( 1966, text-figure, 13A-D). tutus and "transition between the infraspecific An association consisting of elements of Scun- groups is not marked." In the protopanderodiform dolfus unistriatus Sweet and Bergstrom s.f. and element of P. liripipus only two groups could be Scolopodus varicostc~tlrsSweet and Bergstriim s.f. separated easily (see "Description"). The preswas suggested to be a natural species by those ence of the keel in the antero-basal corner of proauthors. The specimens came from the Llandeilian topanderodiform elements is far more common in Pratt Ferry Formation. A younger association, P . liripipus than is suggested by illustrated speciconsisting of Scanclodus? dissimilaris (Branson mens of P . vuricostatu.~. and Mehl) s.f. and Scc~lopodusinsc-ulptus (Branson Protopanderodiform elements of P. in,sculptus and Mehl) s-f. was based on specimens from upper differ from those in P . liripipus by the development Middle and Upper Ordoviciail (Upper Caradocian of a denticle on the base (Sweet et al. 1975, plate 1 to Ashgillian) strata of the North American Mid- (19)). The denticle may be broken off and a lobate continent and Europe. region on the postero-oral portion of the base reThese associations are accepted herein and the mains (Bergstrom and Sweet 1966, text-figure 13). Serpagli (1967, plate 28 (1-6)) illustrated forms apparatuses are referred to the multielement species Protopuncirrodu.~r-uric.ostatu,s.and P. in- from Ashgillian strata of the Carnic Alps, which he assigned to Scolopsd~rs? insc-ulptus. In profile, scaulptusrespectively. S~~bsequently , Bergstrom (197 1, text-figure 4) several of them (plate 28 (1-4)) cannot be distinfigured a lineage from "Sc-olopodus" vuricbost~~tusguished from protopanderodiforrn elements of P. s.f. (Llanvirnian to Llandeilian) to "S." n. sp. cf. liripipus, although the posterior portion of the bases "S." ir~sculptr~s s.f. (Caradocian to Ashgillian), is broken. The termination was probably pointed. which was based on specimens from Sweden. The We refer these specimens to P. liripipus with queslatter form species is the protopanderodiform ele- tion. Two of Serpagli's specimens differ from ours ment of P. liripipus. by the presence of forms with one costa on each In earlier literature, the taxonomy of the con- side (Serpagli 1967, plate 28 (5,6)). We have chosen stituent form species o f P . varicostatus, P. iiripipus to exclude these Carnic Alps specimens from P. and P. inscu1ptu.s has been treated in different liripipus and suggest that they are probably eleways, a problem caused by the intraspecific varia- ments of a different apparatus. No Camel Back tion and paucity of reports of the species. For specimens have one costa on each side. The scanexample, the specimens of Scarzdodus unistriatus dodiform elements (Serpagli 1967, plate 24 (5, 6)) s.f. which were illustrated by Hamar (1966, plate 3 are closely similar to those in the Camel Back mate(1, 7)) are from the Upper Chasmops Limestone rial. The protopanderodiform elements from upper (uppermost Caradocian) and are referred to here as

KENNEIIY E'f AL,.


Carodocian strata in Poland. which were illustrated by Dzik (1976, text-figures 16h, k) as P. itzsc~rlptzrs, have broken bases and are indeterminate as to species. The scandodiform element in P. liripiprrs does not have a rounded postero-aboral region on the base which is present in Sccrndodus ~rnistriutuss.f. from the Pratt Ferry (e.g. Rergstronl and Sweet 1966, text-figure 13C, right) and none have the lobate. posterior extension and flanged, oral edge of Scunciocl'lrs?dissin~ilnriss.f. (Bergstrom and Sweet 1966. text-figure 13D). A small flange is developed on the anterior of the base in about half the Camel Back specimens and a faint notch is developed rarely.

( C ) Kemurks o t ~tempofir1 clnci sprrtic~ldistribution of P. Iiripip~rs Bergstriim (197 1, text-figs. 4.5) indicated that the change from P. vcrric.ostcrtzrs to P. liripipns took place ill the Prioniodus variubili,~Subzone in the lower Dalby Limestone. The position of this change was approximate as both species are rare in the Dalby (S. M. Bergstriim, personal cominunication, 1977). More definitive data on the change was presented by Bergstrom and Carnes (1976, text-fig. 2). Samples from the Holston Formation showed that there is a slight overlap in the ranges of the two species and that the n~orphologicalchange took place low in the Prioniodirs gc~rdrluSubzone. In this respect, it is interesting to note that Repetski and Ethington (1977, table 2) recovered elements of both species and elements of Prioniodrrs gerdae in a sample (CR-1-4)from a limestone unit in the upper part of the Womble Shale near Norman, Arkansas. Several samples from a limestone unit in the Womble Shale at Blakely Mountain, Arkansas (Repetski and Ethington 1977, table 2. samples BM.) were reported to have yielded the two Protopuncierod1r.s species but with elements which suggested the older Pjlgc~dus nn.serinus Zone. Either the identifications of the Protopanderod~rs species need re-evaluation or the timing of the change from P. varicostatus to P . liripiprrs is older than reported. Other reports of P . liripipu,~are consistent with the data of Bergstrom and Carnes (1976). Hamar (1966) illustrated specimens from the Upper Chasmops Limestone of southern Norway (Amorphognathus superbus Zone, Bergstrom, 1971) and Bergstrom (1971) recorded the species from the Balclatchie Group, Girvan, Scotland ( A . tvaercrasis Zone) and the Botetourt Formation, Strasburg, Virginia (P. gerdue Subzone). We concur with the identifications of P. vrrric~ostutusby Viira (1967,

5 49

1974) and Dzik (1978) and point out that the youngest strata from which the elements have been reported in the east and south Baltic region are from the middle of Uhaku Stage (CIc) in Estonia and lowest Kukruse in Poland, i.e. middle to late Llandeilian and hence just older than the earliest record of P. liripiprrs (see also below). The upper range of P. liripipus and its relationship to P . insc>ulptlrsare difficult to judge from the literature. Bergstriim (1971) did not record P. insculptus from his key sections in Sweden, but it is listed as a characteristic species of the Amorplzogtrcrthus ordovicic*us Zone. P. liripiplrs, however, also extends into this zone (Bergstrom 1971, textfigures 4-5). Viira (1970, 1974) recorded P. insc~alptusfrom the Ashgillian Vormsi Stage (FIb) of Estonia and Dzik (1978, text-figure 1) illustrated specimens from the uppermost part of the Mojcza Limestone (upper Amorphognclthus ~ u p e r b ~ r , s Zone, upper Caradocian). In summary, the ranges of the two species appear to overlap considerably. The oldest occurrence of P. insculptlrLsis from late A . ,supcrbus Zone strata and both species range into the A . ordoilicic-us Zone. P. liripipus and related species are typical representatives of the North Atlantic Province. which is well known from the Ouachitas, along the Appalachians and the north Baltic region. P. l i r i p i p ~is ,~ notably absent from Poland and Estonia, although P. varic.ostcltus and P. insczr1ptu.s are present. ( D ) Retncrrks on tlze elemc~ntetlconaposftion of' P. rclric-o.stot~~ Early development of ProtopunderoduS species in the Arenigian produced a variety of forms and a large number of form species have been based on them. The nature of many of their apparatuses has not been determined. Sweet and Bergstrom ( 8962) described Acontiodlrs c-ooprri s.f. along with the protopanderodiform elements of P. varicostntus. Barnes and Poplawski (1973 p. 782) placed elements of A . cbooperi s.f. and elements of Scolopodlrs cf. S . varic.ostcatus in the same apparatus, along with scandodiform elements similar to S . rectlrs and a drepanodiform element (Barnes and Poplawski 1973, plate 3 (1)). The apparatus was named Protopunderocius cooperi. Landing (1976) came to similar conclusions. The apparatus we have reconstructed for P . liripipus does not contain elements similar to Acontiociu,~c-ooperi or drepanodiforn~elements. We suggest, and S. M . Ber-gstrom (personal communication, 1978) concurs, that Acsontiodiis cac~operi s.f. is part of a different apparatus. We do not

550

CAN. J . E,4KTH SCI. VOL. 16. 1979

know the relationships of the drepanodiform eleanent, which was illustrated by Barnes and Poplawski (1973). -

7


Iypes Holotype : GSC 60685 Paraty pes: CSC 60680-60684,60686-60690.

Genus Stt.c~chnr~ogtzuthus Rhodcs, 1955 s.f.

Type spoc.ics : S t r ~ ~ ~ . h ~ l n o g n u ~t lC?I uI 'sI ~ URhodes, S

1955 s.f. Stv"klc'/zcl~?~gnathr~s parryus Rhodes s. f. Plate 1, fig. 24

Str~lchutzogncrthus pav-vrts Rhodes 1955, p. 132, plate 8 (1-4): Bergstrom ct a / . 1974, plate 1 (8): tables 6, 10: Dzik 1976, p. 444. text-figure 14j-k (includes synonymy to 1976). Strachcinogtzat/zuspllrvcr Rhodes. Bergstriim 1962, p. 54, plate 3 (1-6): text figures 3B, 3H, I: Lindstrom 1964, pp. 140- 141, text-figure 48k. non Str~~~chur~og~ntlku,,ztzu cf. S . puv.rlu Rhodes. Greggs and Bond 1971, p. 1469, plate 2 (10, 10a). Kerrmut-ks This is the second positive identification of this genus in North America. The other specimens come from the Cobbs Arm I,imestone, Newfoundland (Bergstrom et a / . 19941, which contains a Pygocius serrus Zone filuna. TY[lc

Hypotype: GSC 60706

Ackn~wledgrnents We thank S. M. Bergstrom, Ohio State University, Columbus, W. I,. Ethington, University of Missouri-Columbia, and G. S. Nowlan, Geological Survey c~fCanada, Ottawa, for comments on the taxonomy. S. M. Bergstrom kindly read an early draft of the manuscl-ipt. C. K. Barnes acknowledges the continuing financial support for conodont studies from the National Research Council of Canada that provided post-doctoral funds for D. J . Kennedy. M. B. Rafek kindly assisted with the photography.

BARNES,C. K.. and POPLAWSKI,M. 1,. S. 1973. Lowel- and Middle Ordovician conodont5 from the Mystic Formation, Quebec, Canada. Journal of Paleontology, 47, pp. 760-790. BERGSIRC~M, S. M . 1962. Conodont5 from the Ludibundus Limestone (Middle Ordovician) of the Tviieren area (S.E. Sweden). Arkiv for Mineralogi och Geologi, 3, pp. 1-61 (preprints dated 1961). 1968. Biostratigraphy of the L,ower Orctovician sequence at Skattingbyn, Ilalarna (abstract). Geologi5ka Foreningen5 i Stockholm Forhandlingar, 90, p. 454.

1971. Conodont biostratigraphy of the Middle and Upper Ordovician of Europe and eastern North ,4nierica. In Symposium on conodont biostratigraphy. Etlitcci by W. C. Sweet and S. M. Bergstriim. Geological Society of America, Memoir 127, pp. 83-141. BI:KGST'R~~M, S. M., and CARNES, J . B . 1976. Conodont biostratigraphy and paleocology of the Holston Formation (Middle Ordovician) and associated strata in Eastern Tennessee. Irz Conodont paleoecology. Editd b?~C. R . Barnes. Cieological Association of Canada, Special E'aper 15: pp. 27-57. S. M., KIVA,J.. ancd KAY,M. 1974. Significance of BERGS~-nijhi, conodonts, graptolites and shelly faunas from the Ordovician of western and northcentral Newfoundland. Canadian Journal of Earth Sciences, 11, pp. 1625- 1660. H E R O S ~ T KS.~ M M., . and SWEEI',W. C. 1966. Conodonts from the Lexington Limestone (Middle Ordovician) of Kentucky and its lateral equivalents in Ohio and Indiana. Bulletins of American Paleontology, 50, No. 229, pp. 271-424. BIRD, 9 . M., and DEWEY,J. F. 1970. Lithosphere platecontinental margin tectonics and the evolution of the Appalachian orogen. Geological Society of America Hulletin, 81, pp. 1031-1060. BRANSON. E. L\., ;ind MEIIL.,M. G . 1933. C'onodonts from the Maquoketn-Thebes (Upper Ordovician) of Missouri. University of Missouri Studies, 8, pp. 121-132. DAVIES,J. I,., FYI~FE, L. K., and IRKINKI, K. K. 1973. Geological mapping in the Mirimichi zone. Irz Cjeological investigations in New Brunswick. New Brunswick Department of Natural Resources, Mining Division Branch, pp. 19-25. DZIK,J. 1976. Remarks on the evolution of Ordovician conodonts. Acta Palaeontologica Polo~aica.21, pp. 395-455. 1978. Conodont biostratigraphy and paleogeographical relations of the Ordovician M6jcza 1,imestone (Holy Cross Mts, Poland). Acta E'alaeontologica Polonica, 23, pp. 5 1-72. ETHINC;.~ON, R. I ,. 1959. Conodonts of the Ordovician Galena Formation. Journal of Paleontology, 33, pp. 257-292. F ~ I I K A E UL. S ,E., and NOWL.AN. G . S. 1978. Franconian (Late Cambrian) to early Champlainian (Middle Ordovician) conodonts from the Cow Head Group, western Newfoundland. Journal of Paleontology, 52, pp. 444-471. GREC~GS, R. G . , and BOND.I. J. 1971. Conodonts from the March and Oxford Formations in the Brockville area, Ontario. Canadian Journal of Earth Sciences, 8, pp. 14.55-1471. HAMAR, G. 1966. The Middle Ordovician of the Oslo Kegion, Norway. 22. Preliminary report on conodonts from the Oslo-Aster and Ringerike districts. Norsk Cjeologisk Tidsskrift. 46, pp. 27-83. HADDING, A . 1913. Undre DicelBograptusskiPfern i Skzinejiimte n%gra durmt'd ekvwalenta bildningar. Lunds Universitets .Arsskrift, N. F., 2, pp. 1-90. HARRIS,R . W. 1962. New conodonts from Joins (Ordovician) Formation of Oklahoma. Oklahonia Cieology Notes, 22. pp. 199-21 1. HENNINC~SMOEN, (3. 1948. The 'Tretaspis of the Kullatorp core. Geological Institution of the University of Upsala, Bulletin, 32, pp. 374-432. LANDING, E. 1976. Early Ordovician (Arenigian) conodont anti graptolite biostratigraphy of the Taconic allochthon, eastern New York. Journal of Paleontology. 50, pp. 614-646. I , I N D S I . R ~MI. M ,1955. Conodonts from the lowermost Ordovician strata of south-central Sweden. Geologiska Fiireningens i Stockholm Fiirhandlingar, 76, p. 517-604. 1964. Conodonts. Elsevier, Anisterdam, 196 p. 1971. Lower Ordovician conodonts of Europe. I n Symposium on conodont kiostratigraphy. Etiiteci by W. C. Sweet and S. M. Hergstrom. Geological Society of America, Memoir 127, pp. 21-61.

KENNEDY ET AL.


-- 1977. Briltottiodus alohtrtl1.s (Bcrgstriim 1 9 7 1 ~ ) .In Catalogue of conodonts, Vol. 111. pp. 65-67. Editcjtl hy W. Ziegler. E. Sctiweizerbart'sche Verlagsbuchhandlung, Stuttgart. 574 p. M C U K I D ~11. , E . 1976. Tectonic setting of the Tetagouche Group, host to the New Brunswick pulynietallic massive sulphide deposits. I n I\lletallogeny and plate tectonics. Ediretihy HI. F. Strong. Geological Association of Canada, Special Paper No. 14, pp. 473-485. E'ANULK,C. H. 1856. Monogl-aphie der fossilen Fische ties silurischen Systems des I-ussisch-baltischenGouvernernents. Buchdl-uckerei der Kaiscrlichen Akademie der Wissenschaften, St. Petersberg, 97 p. R A S ~N., , and STKINC;ER, P. 1974. Recent advances and the interpretation of the geological structure of New Brunswick. Geoscience Canada, 1, No. 4, pp. 15-25. R E P E T S K I9, . I:., and E - r r ~ r ~ c i ~R. o vl a, .1977. Conocionts from grnptolitic facies in the Ouuchita Mountains, Arkansas and Oklahoma. In Symposium on the geology of the Ouachita Mountains, 1, pp. 92- 106. K ~ ~ o r ~ rF. : s H. , T. 1953. Some British Lower Prilaeozoic con