1 "
C0N0D0NT3 FROM THE aLSN DEAN TORHATION OF K :rr
AND E(iUIVALENT FX)RKATI0NS OF VIRQINIA
AND WEST VIRQINIA
by
CHARLES EDWARD CLARXE, B. 3.
A THESI3
IN QEOLOaY Submltted to the Graduate Faculty of Texae Technologlcal College In Partlal Fulflllment of the Requlrements for the Degree of
MASTER OF SCIE.^;CE
k. . / TABLE OF CONTENTS
INTRODUCTIOM 1 Purpoee and Scope 1 Prevloui Work In the Area 1 Methodi of Study 3 Acknowledgments ^ STRATICRAPHY 5 CONODONT FAUNA 21 Abundance of the Fauna 22 Stratlgraphlc Impllcatlons of the Fauna 2k- Unlformlty of the Fauna 25 SUMMARY AND CONCLUSIONS 2S LIST OF REFERENCES 29 APPENDIX A: Syetematlc Deecrlptlone 33 Qenus Cavusgnathue 33 CavusgnathuB convexa Rexroad 33 CavuBgnathue crlstata Braneon and Mehl 3I4. CavusgnathuB unlcornis Youngqulst and Mlller . . 36 Oenut CeniculatuB 37 Ceniculatufl of. 0. claviger (Roundy) 37 GenuB QnathoduB kO CnathoduB bilineatus (Roundy) kO Q-nathoduB modoceneÍB Rexroad , k2 Oenus Ligonodina kk
ii 111
Ligonodina cbunca Rexroad ^^ OenuB Lonchodina ^ Lonchodina furniBhi Rexroad ^ Lonchodina cf. L. paraclarki HaeB 5^ GenuB Metalonohodina 5^ Metalonchodina ep. ^l OenuB NeoprionioduB 53 NeoprionioduB ligo (Hati) 53 NeoprionioduB scituluB (Branson and Mehl) ... 55 NeoprionioduB cf. N. eingulariB (HaBB) .... 5^ Q-enuB Ozarkodina 5^ Ogarkodina compreeea Rexroad 5^ Q-enus SpathognathoduB 6o Spathognathodus campbelli Rexroad 6o SpethognHthodus cf. ^. comautatus BranBon and Mehl 6l
ILLUSTRATIONS
FIGURE3
1, Conodont Colleoting Localities 2 ?• Qeneraliztd Correlation of the Cheeter Seriøt in the Area of 3tudy B 3. Yellov Rock, locality 1 10 k. Pine Hlll, locality 2 12 IT
5. Big Stone Gap, locality 3 1*^ 6. Qreendale, looallty k 16 7. Biehop, looality 5 iS S. Alta, locality 6 20
TABLE
!• Qeographlc Occurrence of Conodont SpecicB 27
PLATE
1. Olen Dean •^ABsemblage-Zone" Conodonts M ABSTRACT
The conodont fauna from the Qlen Dean Llaestone of eaetern Kentucky, Cove Creek Limeetone and Bluefield Shale of western Virginia, flnd Bluefield Group of southeaBtern Wtst Virginia 1B deBcribed, SampleB were collected fro« 8lx localities and virtually every eample from limeetone and many froa fhale yielded conodonte. Thlrty-four •pecleB were recognized and are refer- ftble to fourteen genera: Cavuegnathus, GeniculatuB, Q-natho- due, Hlbbardella, Kladognathus, Lambdagnathut, Ligonodina, LonchoQÍna, Meta 1 onohodina, ^ieoprionic 1-;P , Ozarkodina, Roundya, Spathognathodus, and Subbryantodue. The fauna is unaffected by lithologic variatione and 8how8 no geographic restrictions. The writer proposea that the Qlen Dean Limeetona, Cove Creek Limestone, Bluefield Shele, and Bluefield Qroup conBtitute a Bingle CavuBgnathus unicornis ABBemblage—zone. INTRÛDUCTION
Purpoee and Scope
The purpoee of thie theelfl ifl to preeent a etudy of conodontB from the Qlen Dean and equivalent formationfl from flelected outcrope In eaatern Kentucky, weetern Virginla and floutheafltern West Virginla. The Qlen Dean and adjacent formations were chosen for Btudy because: 1. Correlation of the formatione ÍB well efltablish- ed; therefore, time equivalency of the varioue formationfl Is aeeured. 2. The Qlen Dean Formation contains an abundant oonodont fauna In the Illinoifl Baein (1,P). 3. Afl the Qlen Dean equlvalente become thicker and contain more claetic bede In the eaetern part of the area, they become preferred units for biofaciee analysefl (2).
PreviouB Work in the Area
Rexroad (1) publlflhed a preliminary report concern- ing oonodonts from the Cheeter Seriee In the type area of 8outhwefltern IllinoiB. Later he publiehed a more detailed fltudy of the conodont fauna of the Qlen Dean Formation around the margin of the Illlnolfl Baein (?). The preeent paper ie a further evaluation of the Qlen Dean fauna. «)
• H Methodfl of 5tudy
Fleld Prooedure8
From each expoeure, compoflite flamplee of all lithio unitfl except eandfltone ware oollected. Qenerally, cono- dontfi from flandetone are not preeerred well enough for Iden- tification. Each sample wm8 approximately five feet thlrk. Composlte eamplee, two f€»!t thick, were takcn from the Pine Hill secticn (locality 2, figure 1). Each lithic unit iimt deBcribed and a numerlcal designation asfligned tc it.
Laboratory Proceduree
Approximately 600 grame from each eamplt vas treat- td to recover conodonts. Limestont eamplee wtre cruehed to lees than 5/í5 inch prior to digeetion in 10 percent acetic acid. Mofit ehales were disaggregated by boiling in water and flodium bicarbonate, but othere were dÍBaociated by uie of the Campbell microfoflsil waehing •aohine or eoaklng In Stoddard Solvfint (naphtha). ReBiduoe wtre ecrtened and the portion retained between the 20- and lOO-mesh flortens vat conoentrated by gravity ecparation in bromoform. Conodonte picked from the heavy rcBiduefl were grouped, firtt by 8( plt and looation number, then regrouped by genue and tpeciee. Identification of flDCcimenfl wae based on work of prcviouB authorfl. The fauna is rccordcd on the oocurrenot ohJ.rt (Table 1).
Ackr;owledga:ent8
The writer ie indebted to Dr. John P. Brand, who acrved as chairman of the thesÍB committee and adviecd throughout all Dhaetfl of the work. Mr. Deekin H. Shurbet, Jr. and other menbers of the Qeology Department of Texae Tcchnological College provided aBflÍBtance and laboratory facllitlee. Thankt are aleo due Dr. Carl B. Rexroad, formerly of Texas Technological College now In the department of geology, the University of Houston, who suggefitcd the prob- lem, and provided Bamplee for study. Othere who generously gave time and energy to thle Btudy are Dr. David H. Swann of the IllinoÍB State Qeologi- oal Survey, who collccted samplcfl at the yellow Rook quarry (locality 1). Qrover Emrlch, aleo of the IllinoÍB Survey, aided Dr. Rexroad In collecting ^amples from the reraaining localiticfl. 3TRATI 3?.ArHY
The Qlen Dean Limestonc, Cove Creek Limeetont, Bluefield Shalc are distinct lithoetratigraphic unitfl and deeignate three facice of the eamt bioetratigraphio unit In the area of study (3). The Qlen Dean Limcstonc wae named by Butts (^4-) from Qlen Dean, Brcokenridge County, Kentucky; the Cove Creek Limestone was also named by Butts (5:16) from Cove Creck 5 miles southwest of Mendota, Scott Gounty, Viri^inia; the Eluefield Shalc wae named by Campbell (6) from Blue- field, Merccr County, Wcet Virginia (3). At Alta, Qreenbrier County, Wcet Virginia (locality 6, figure 1), a eomewhat doubtful (7»^) Qlen Dean Limestone cquivalent is known as the Blupfield Qroup. This Qroup ie tht lowcrmost portion of the Mauch Chunk Serlcfl and is sub- divided Into scveral formationa (9>10). Inasmuch as tht Olen Dcan Limestone, Cove Crcek Limestone, Bluefield Shale, and Bluefield Qroup are characteriied by a eimilar definl- tive fauna, the writer propoflee that thcsc four lithio unltfl belong to a single a88tmblage-zonc. Accordingly,
^ Hedberg (11). The ateemblage-zone may bc dcfined a8 a btd or group of bcde charaoteriied by a oertain aeto- clation or aeetmblage of fossil formt, distinctive either with rcepect to the taxonomic entitlee re- rceenttd, tht abundance of flDecimens, or both. The »^flemblagt-rone ie uBually namtd from flome one foflflil form which is particu- unltfl aflflignable to either of the aforcmentioned litho- etratlgraphic unite will be rcferrcd to aa the "aflBemblage- rone.* A etoondary purposc of this study is to aeflign defi- nitc gencric or flpecific nomenolature to thie "ae^tmblagt- zone. •• The Qlen Dean '•atsemblage-zone, " although variable in thickncBB and oompoBÍtion, ia a well defined unit over •OBt of thc arca of study. In Kentucky (localitiee 1 and 2), it overlies, with secming conformity, the Hardinsburg ( ••Pencil Cavc") Formation. McFarlan and Walkcr (12) report- ed thc "Pencil Cavc" to be corrclative with the Hardinsburg Formation, a well cstablished unit in the standard Cheeter Scritt, Unconformably overlying the Qlen Dean Llmtttont at localiticB 1 and 2, are bede of the Pottsville Series of Ptnneylvanian agt. In Virginia (localities 3, k and 5), tht Stony Qap Sandstone Membcr of thc Pennington Formation conformably overliee the Qlen Dean '•atBtmblage-ione;" which, in turn, overlies the Qaeper Limeetone, an equivalent to the upper Qrcenbricr. Near Qretndale (locality k), a relatively thin larly reprcscntative of the aBBcmblagc, although it need not be confined to the unit or found in evcry Dart of it. Thc asflemblage-zone is morc or lcflfl eynonymoufl with what have bcen called faunizones or florizones. The horizontal and vertical extent of an aBsemblage-zonc is limited to the obBcrvcd horizontal and vertical extent of the atBtmblagt. tandetont, looally calltd tht Fido Sandetone, licfl bttwetn tht "aettmblagt-zont*' and Qaeptr Formation (3:3^9). In Vttt Virginia (locality 6) the Qlen Dean '•atfl blage-zont" oonformably overlicfl the Qrtenbritr Limtttont and Í8 overlain oonformably by the Hinton Qroup of the Mauch Chunk Scriefl. The llthologic sequence of the BÍX eeotionfl is glv tn in figures 3-S. Samplcs which oontain conodonte are thown in black. The stratigraphic ooflition of the Qlen Dtan •'assemblagt-zone*' is shown in figure 2. Lithically, thc sampled flections vary from 100 per cent limcfltonc In Kentucky, to domlnantly flhale at tht Blshop, Virginia section. The limestone portlonfl of the Qlen Dean are ueually medium gray, medium grained, crinold al, oolitic, BiliccouB or argillaccouB and foflflilifcroue. The flhales are variegated, caloareouB or Biliceoufl and fre quently contain limestonc, sandBtone, or siltfltone inter- bedfl. •
TJ •H Gr . o rou p CsO c o U •H a> c o o. 01 a> tû >» c o *-> 3 TJ •H C li *J o «J C O ^ u o -rH -H • . «-> a> -H U a> ^ *-> t* ^ c> V) O X o •H c n •J —- a> c
Z
•H 3Í U3 (3 )
to Shal e Gaspe r
a: Virgini a Localit y 4 Penningto n Llmeston e
f- Cov e Cree k Ls . Fid o Sandston e :0
^3 o o • »-» (0 u. U3 C -J íTJ o c • f- •H >> 4-> O c u e C *J bû -H CTJ 0) o U, •H •H—« C 4-> 0) (X ^ o •H (« Q m n « a> ^: •ri O C o s O > O a> o a> •ri i—í —1 a. u t-t •-) t- o o >< u —1 a> u Æ: m £x: (>í o • o
Q U > ^O n M *-> (12 ) ^-1 Hane y c
•< Paol i cfl (Break ) -r: Kentuck y >, Reelsville - Beec h Cree k >o Beve r Ben d U "Penci l Cav e Gle n Dea L s ca
Localitie s Ik !•_ t"t H # • • • . (0 (0 n B • • CO cn • to u. n • co 0) • to n c • • CO 00 n .-J bO E • JH « cn o CT) 10 • t. • oo u CL. n 9 n •r-< -J CO • 0) 0) 3 0) c c 3 cn 9 g _) n '» • • E c ^ x> -J •H (fl x> « U o a> :' O T3 cO u. •H (0 u a> n •o n O 4J 4J n .i: •H •H *-) TJ u (S Q. Q c c n a> .—• «9 OJ
'¥it-''-'
rigure 3. LOC l-YELLOW ROCK
grO*»ea, Cf*XX>Ol. wt^ttttri pow
LTíetton*, pow f»iio«»'W> C- • j
"•»>aW, groy. Wy. «•'"' '»*>,'•<)•»• yOy, 'ne-jraí^ea, sondy, >otvl Flgure 3- •ti aanSTi qSnoaqcj.\iSATH ITS^f^d: jo CÍBS UT p^iOtiiT^H ujaqanog SuoiT8 pQjrrisieaui ídie-o 9Uoq.s ^'TQ jo tí:i.J:ûu ÔITUÍ B JO 5Z*0 ifiaaBmTxoadûv •£ iíaTT^ooi 'de-D 9uo!).s STQ '5 aanSiJ ÍI i LCX 3 BlC STONC GAP h kll#**w r^. Flgure 5. LOC 4-G«£N0ALE m ..-• ' ^SJL* IIO -^ •o M •. «>. »tmt «•>«• 40 «1 l"( M.I '•* Wh fr. 11 * ^3 I • — * c> * To *• • «0 I j-s-: irr: '•« ' S5^ rrr T. — >* * s» Flgure 6. n LOC 5-B4M0f> h 4 m «*« Mta • •' M I o -I UJ 3 3^ » .«or ;^;;:i Flgure 7 Flgure 8. OONCDONT FAUNA A conslderable varlety of conodonts wme recovered from all slx Slen Dean ••aBiemblage-zone'' eectlone. Thlrty- four specles, referable to fourteen genera, were Identlfled. Four addltlonal genera, Hindeodella, Synprioniodina, Icrio- ^^? and Polygnathus. were recognized. Of these, Hindeodella (the only abundant genus) and Synprioniodina have long geo- logic rangee and are not considered to bc of stratigrarhic significance. Icriodus and Synprioniodina are reDresented by one fragment each and Polygnathus by two fragments. These three genera occur hlgh in the seotion at locality k, The ooly- gnathids and Icriodus were found in samples 106 and I07 re- spectively. Reworking of these Gpecimens seems evident as Icriodus Í8 a well eBtablished Devonian form (l^). Although Rexroad (1:11) recorded three fragments of Polygnathus froM the Renault Formatlon, the genus is generally considered to be no younger than middle Mississlppian (1^^-). Two genera, Q-eniculatue and Metalonchodina, were not recorded In the area of the type Chester (1,2), however, they have been reported from the Barnett Formatlon (I5) and Hass (15:72) recognized both genera in the Caney Shale faun* 2 Rexroad^ rersonal communication (May 1959). "I co nfident those /polygnathid^_ _ _ / were reworked." 21 22 of Branson and Mehl (16). Metsl- ;ãina Is repreeenlevi by one speclBen from the upperiDost saaple (sample I5) of local- ity 3. Although rare, &eniculatu6 vae identifled froa fivt of the 6ix collecting lccalitltE. A' :e of t> e F^una Conoâont speoimens froB nearly all saaple reelduea 9LT% fragaant&l and identifioation to oatrí'orles belov pcnus is diffioult. About one-tMrd of the total epeciaens {l^ô'^) ara too fragaental to bc Identifieâ as to genus and are In- dioated on the ooourrenoci chart as Oenus indeterainate. Conodonte are more abundant than thc Identifiablc Bpecimene indicate, and are conaon fi-om four of the slx outorops saa- pled.-^ In the remaining sectlons (localities k and 5) oono- h donts are very rare. The later Eections ars the i 1 esx outcrops saapled. The aost abundant specles encountered is Cavus- gnathus unicornis Youngquist and Mlller. Neoprioniodus scitulus (Branson and Mehl) is tht seoond most abundant species. ^ ll-?5 specimens per 1000 grams of unprocessed aample. k 1-5 speciaens per 1000 graas of unprocessed saBple. 23 Species considered to te cc.naon in ordtr of de:;raas- ing mmbars are: Li^oncdl.'.a hJLitats Hexro.iÆ, Cwusgnachuc Ct^rivexa Rexro^d, Sp.ithc^/.^thodug :f. 2« cr'Tnwucat js Branson aad y-îhl, Q-.atb-Igg iiodc-enalit '^exroad, Cavusgnathus cristata Branson and Kehl, Ligonodina obunca Rexroad, Ona- ^^Q^^g bilineatuB (Koundy), Neoprloniodus varians (Branson and Mehl), Spathognathodu J c.-iMtul.i Young'iuist a.id Miller, *i"*-^ l'*Tla .T.llleri HexroHd. The fra^ir.erital natare cf tr-* conoiTntis nreveatt furtr.er tíubdivislDn of thp .ipeclea into an :jacomnon or r-^rt olíTSSificíítion. CoGoletií apeoimeas oî Oz.^río il.iii oo " ^^'essa Rexroad and O.* 0^."^;:!^^ i^exroHd tíre incoiAmon ^ " '^nre, but nuiîierous Ozarkoiina frAgments sugges^ those aoeo y be nore abualant. The rsi'i''inlnc$ nl:iet'»eíi ape'^les are consid- ered uncc'mnon or rare i-n ths a-len Deftn ^asaeiablíiû*""^'^®* ** thest are: CavuHgnathus characta Rexroad, ^. cf. C. regu- laris Youn^ui:t ap.j'. IIMler, CV<%niculatuf cf. G. olaviger (Roundy), Hibbardella orth^ Rexrcad, Xlaaognf.thue priaa Hexrcad, Lcimbdagnathus rra^ilid^nc Rexrcad, Ligonp.'ina roundyl Hass, Lonchodina furnishi Rexroad, L. cf. L, para- clarki Hass, L. paracl^viger Rexroad, Neoprioniodus of. ]J, federatus (Elias), >:. of. N, inclinatus (Hafis), N. ligo (Hass), ÎJ. cf. ÎJ. singulari8 (Hass), Roundya of. R. barnettana Hass, R. costnta Rexroad, Spathognathodus oamp- belll Rexroad, 3, spiculus Youngquist and Killer, 2h Subbryantodus cf. ^. flexue Branson and Mehl, and Metalon- chodina sp. Stratigraphic Implications of the Fauna The generic composition of Olen Dean "assemblage- zone** conodonts in the ares of study Is nearly Identical wlth the Olen Dean of the Illinois Basin. Only two genera, Q-eniculatus and Metalonchodina, have been added by this report. On the occurrence chart (Table 1) the coluant on the right are devoted to comDarison of genera and epecies of this report with those of the upper conodont zone of tht Barnett Formation of Texas, the Delaware Creek Member of tht Caney Shale of Oklahoma, the Pella beds of lowa and the Qlen Dean Formation of the Illinois Basin. Ten genera from the Barnett Shale are common to tht Olen Dean; however, the Qlen Dean contalns four genera not reported from the Barnett Shale. The Caney Sh^le fauna con- tains nine genera common to the Qlen Dean, but five genera from the Qlen Dean have not been reported in the Ganey Shale. All genera identified by Youngquist and Miller (I7) from the Pella beds are present in the Qlen Dean "assemblage- lone*^ but eight Qlen Dean genera have not been reported from the Pella beds. 25 Conodonts from the Bamett Formation ^nd Delaware Creek Member of the Caney Shale resemble the Qltn Dean ••atstmblage-zone*' fauna. Uniformity of the Fauna Rexroad (?) emphasized the over-all uniformity of the conodont fauna in his study from three standpoints: First, uniformity in differing lithologies; eecond, uniformity between the lower and upper parts of the for- mation; and third, geographic uniformity. The same relatlonship appears in the writer's area: first, no noticable restriction of conodont SDecies to specific lithic types; eecond, consistency of the fauna betwetn lower and UDper parts of the "assemblage-zone;" and third, no geo- graphic restriction of the fauna. Conodonts appear to be more abundant and better pre- served in limestone than in shale; however, no pi^nificant differences were found in tht species recovered from differ- ent types of limestone, or betwten various kinds of shale. Spathognathodus campbelli Rexroad, limited to ehalt In Rexroad's study (2), was confined to llmestone from a single locality in this report. Qnathodus, Kladognathus and and Lambdagnathus were not recognired in collections froa locality 1. A single specimen of Subbryantodus was collect- td from thalt. Dlfferences art slight in overall considera- 26 tion of the Qlen Dean "•asstmblage-zone" fauna and probably rtflect the method of sampling rather than environmental factors. ' . - - • • V. »p»: :•» -..' •r. Is r.tor ssin •.. •.;.•; O •1 a • 1 T u t. «4 r— * • -? o • • a íi . 1 T 7? TX -• • 1 •' •ro ÎÎS n o-r J . ' 1 —•'i—"*" i*j X s j , ' 1 - 454 s - " X X 1 1Ô< 1 W. - - m ! 'l'• •1" 7 « - - X ) X - - - . . . Â 1«'' 1 X . 1. 1 .• X s 9 ! X , . 23 11 - X X X X - .--• jrtna 3 - - X - X - • •U_:.. 15» * X ( 16« 0 X A - - (• - X - A - - - - - • " 1 ' 'i ' ' 11 13 •• - - X X X X . - f í • ~ • • X " - X ., " ' T 8 ' • " X X " X - - - - A " • * - - X ------ A A ^ ^ . _ X X X X _ . _ - X _ j I •>« 32 X X X X V X X X - 1 . •l ' • ' 1 * "i * * i V n X - - 1 - 10 •: - - - .• ^ . X - X A ------1 - l. pir " 1 - '••••• :;na sp. - - - X ------. 2i - - • y 3 • :,7l 120 ' ; - X X X X : 1 X - X - -< - • . . - ! 1 • ' 1 .5 1 :.» _ . « X. X . -! - _ - 1 . . 1 ' 36 6 1 . - - - X - X 1 - * ~ ~ * - - 1 , .1 1 .í C - ' "1V 1 - -1 - - .1-1-1 X 3 1 .1. - X - - J . . 1 - X 1 A H. X - - - • « ' » -2 j X - . - X X X 1 X X X X 1 X X X X i. „ . . . . . •fl 27 ;^ , . . . . 16 .> . . X . 2 3. N • • 1 • - j X 1 X 1 JUI - - . - . . . X - i ' ;Î • • • " - . X • - J , 1 1 1 sp. X ...... 1 1 ! X ' - í . sp. - - - - - * - X - - - . X " - X 627 iír.'as ind«t«ral r.att X X X X X X X X X X X X X X X X K'_.-. «t • . 1C9 « 136 }62 1 i 1 1 >*a.pl«s s*z;I«. SUMMART AND OONCLUSIOW (1) The conodonts in the Qlen Dean "attemblagt-zone" art virtually unaffected by lateral changes in lithology and, therefore, are ueeful for correlation purposes. (2) The variety and abundance of conodonts in limestone are of value to stratigraphic studies in carbonate sections (3) The conodont fauna from the •'asstmblage-zone'' of the writer's area ia similar to the fauna from the Qlen Dean Formation of the Illinois Basin. (4) The writer proposes that the Qlen Dean Limestone, Cove Creek Limestone, Bluefield Shale, and Blupfield Qroup oonstitute a slngle assemblage-zone. In view of the aforementioned faunal oocurrences, the name Cavus- gnathus unicornis Assemblage-zone is proposed. 2B LIST OF REFER^ -^3 (1) C. B. Rexroad. •'Conodonts from the Chester Series in the Type Area of Southweetern Illinois,* Illinois Qeological Survey Report of Investigations 199, ^^' "Conodonts from the Qlen Dean Formation rChesterT of the Illinois Basin, •• Illinois Qeologi- Q^^ Suryey Report of Investigations ^Qc, 1955, pp. 1-^7» Pls. 1-6. ^ (3) Charles Butts. "Qeology of the Appalacnian Valley in Virginia,'* Bulletin of the Virginia QeolOpTÍcal Sur- 121» 5^# Dart 1 U940), pp. l-^bS. (^) . "Deecriptions and Correlation of tht í^ississÍPDÍan Formations of Western Kentucky," Kentucky Geological Survey, KisBÍBSÍPpian Forma- tions of Vestern Kentucky, 1917, p. ^V. (5) . "Oil and Qas Possibilities at Early Grove, Scott County, Virginia,'' Bulletin of the Virginia Qeological Survey, ?7 (1927}, pp. I-18. (6) M. R. Campbell. ••Q-eological Atlas (No. ^6), Pocahontas Folio,*^ United States Qeological Survey, (I896), p. 3. (7) P. H. Price and E. T. Heok. •'Qreenbrier County, "^ 's^et Virginia Geological Survey, 1939, pp. 15^^-29^. (í) J. M. Weller et al. ••Correlation of the Mlssissippian Formations of North America,'^ Bulletin of the Qeo- logical Society of America, Vol. 59, No. 2 (I9U8), ppT 91-19b, Pls. 1/d. (9) D. B. Reger. ••Mercer, Monroe and Suramers Countles," West Virginia Geological Survey, I926, pp. Ul^-i^-U^. (10) •'Webster County,^' West Virginia Qeologi- cal Survey, I920, pp. 227-22^; (11) H. D. Hedberg. ••Stratigraphic Classification nnd Ter- minology, •• Bulletin of the American ABSociation of Petroleum Geolo-zists, Vol. U?, No. 8 {1%^), p. 1557. ' ?9 30 (12) A. C. MoFarlan and F. H. Walker. ••Somt Old Chester Problems-Correlations Along the Eastern Belt of Outcrop,'' Bulletin of the Kentucky Geological Sur- vejr, Series 9, NO. 20 (1956), pp. 1-36, figs. l-i?7» pls. 1,2. (13) R. H. Wilpolt and D. W. Marden. •'Upptr Mississippian Rocks of Southwestern Virginia, Southern West Vlrginia, snd Eastern Kentucky, •• United States Qe- ological Survey Oil and Qas Investigations Prelim- ina?y Chart, 3« (1949). î Sheets. " (Ik) S. P. Ellison. ••Conodonts As Paleozoic Quide Fossils,^* Bulletin of the American Association of Petroleum gtologists, Vol. 10. L'o. 1 (194b). rp. 91-11^. (15) W. H. Hass. •'Conodonts of the Barnett Formation of Texas,** United States Geological Survey Profes- sional Paper 243-F, 19»;;, pp. 69-94, pls. 14-16. (16) E. B. Branson and M. Q. Mehl. "Caney Conodonts of Upper Mississippian Age,** Denison University Bullt- tin, Journal of the Scientific Laboratories, Vol. 35 (1940), pp. 167-17», D1. 5. (17) Walter Youngquist and A. K. Miller. ••Conodontt from the Late Mississlppian Pella Beds of South Central lowa,^' Journal of Paleontology, Vol. 23, No. 6 (1949), PP. 617-6:^2: The following refertnces wtre used for classifioa- tlon and identification purposes but were not cited in the text. R. S. Bassler. ••Classification and Stratigraphic Use of Conodonts," Bulletin of the Qeological Society of America, 36, No. 1 U9^5;, pp. '^l^-'^do. E. B. Branson and M. G. Mthl. '•Conodont Studies,^* Missouri University Studies, Vol. S (I933), PP- l-349i pls. l-ífo. 31 E. B. Branson and M. Q. Mehl. "New and Little Known Carbon- iferous Conodont Qenera,** Journal of Paleontology, Vol. 15, No. 2 (1941), ^j,, 97-lOb, pl. 19. ^ , . ••Conocu n:F, •' in H. W. Shimer and R. R. anrock, Index Fossile of North America, 1944, pp. 235-246, pls. ^3,94; Mew Vork, Wiley and 3ons. j—w—s ••Conodont Homonymt and Namts }P Replace fhtm," JourT î^l of Paleontology. Vol. 22, No. 4 (194«), pp. 5:^7^;?^. -^ ^ C. L. Cooper. ••Upper Kinkaid (Mississippian) Microfauna from Johnson County, Illinois,** Journal of Paleontolog Vol. 21, No. 2 (1947), pp. íl-91^, plf. 19-?3; reprintS ^B Illinois QeoloRioal Survey Report of Investigations 122" —^^ '^—' "^ ?ind L. L. SI088. "Conodont Fauna and Distribu- tion of a Lower Mississipiiian Black Shale in Montana and Alberta,'' Journal of Paleontology. Vol. 1, No. 2 (19-3), pp. l6g-17fe, pls. 28,?9. ^ M. K. Elias. •'Upper Mississippian and Lower Pennsylvanian Formations of South-Central Oklahoma,** American Associa- tion of Petroleum Geologists, Petroleum Geolo^-y of Southern Oklahoma, Vol. 1 (l9^fe), pp. ^8-1-^4. ple. 1-6. . "Some Misslssippien Conodonts from the Ouach- ita Mountains, •• Dallas and Ardmore Geological Societiee, The Geologv of the Ouachita Mountains, A^Symposlum, 1959, PP. 141-165, pls. 1,?. ' '^ S. P. Elllson. "Revlsion of Pennsylvanlan Conodonts," Jour- nal of Pflleontology, Vol. I5, No. 2 (1^41), pp. lO^rif^, pls. ?0-?3. R. 0. Fay. ••Catalogue of Conodonts,'* University of Kfi^ns^g Paleontolot2;ioal Contributions, Ver^ebrata, Art. 3 (195^)» pp. 1-206. W. H. Hast. "Age of the Starley Shalt,** Bull ctin of the American Association of Petroleum Geoiogists, Vol. 34, No. 7 (1950), PP. 157^15^4. > "Agt of Somt Black bhsies in Cores frora North- east MissisEippi, " Missiesippi Qeoloc-ical Societv Guidt Book, llth Field Trip, 19^.4, rp. 1^,3 . 32 "* T*T ?t*î'a ^°'^°^o"^8 f^if^ the Chappel Limestone of Texat," ynited States Qeolo^ical Survey Professional Paper 29W, i9t>y> pp. 3bb-i99. pls. 11^-50.'^ ^ ^— F. H. T. Rhodes and K. J. Muller. "Tht Cor ' t Genus Prionlodus end Releted Korms,'^ Journal .. rPleontology, Vol. 30, No. 3 (1956), pp. 695-^99: -^ ^ H. W. Scott. •'Conodont Assemblaget from the Heath Formation, Montana," Journel of Paleontology. Vol. I6, No. 3 (1942), PP. ?93-30l, pis. 37-110. ^ . 7 , APPENDIX A SYSTEMATIC DESCRIPTI0N8 Phylum VERTEBRATA Olatt PISCE3 (?) Order CONODONTOPHORIDIA Eichenberg, I93O Pamily IDIOQNATHODONTIDAE Harris and Hollingtworth, 1933 Subfamily IDIOQNATHODONTINAE Harris and Hollingsworth, 1933 Otnus CAVUSQNATHUS Harris and Hollingsworth, I933 Type tpecies: Cavusgnathus alta Harris and Hollingsworth CAVUSQNATHUS CONVKXA Rexroad Plate I, Figures 1 and 2 Cavusgnathus convexa Rexroad, 1957* Illinois Qeol. Survty Rept. Inv. 199, p. 17, pl. 1, figs. 3-6. Rexroad, I958, Illinois Qeol. Survey Rept. Inv. 209, p. 16, pl. 1, figt. 12-14. Dttoription: Oral vlew.—Platform long, narrow; trough dttp, straight, one small node prtsent at posterior end; parapett ntarly straight, ornamented with regularly spaced, parallel, trantverse ridges becoraing obsolescent Into the trough; blade dtntiolts laterally oomprtssed. Lateral vlew.--Oral margin of both oaraptts oonvex, more convtx potttriorly; Dosttrior end rounded; blade oom- 33 3^ postd of six dtnticlet fustd nearly to apicet, blade with rtgularly convex oral outline, hlghest at mid-length, length of blade approximately ont-third length of sptoimen, one- third fret. Aboral view.—Navtl of moderate depth, asymmetric, lanceolate-shaped outline, point reaching posterior tip, inner lip with greater flare; central groove txtends ante- riorly from navel along otherwise sharp line. Rtmarks: Length of figured specimen is .80 mm.; mature form. Similar in all respects to the holotype. Oocurrence; Localitles 1, ?, 3, 4, 5 and 6. Rtpository: Illinois State Qeological Survey, 14P-1 (hypotype). CAVUSQNATHUS CRISTATA Branson and Mehl Plate I, Flgures 8-10 Cavusgnathus cristata Branson and Mthl, 1^40, Denison Uni- versity Bull., Jour. Soi. Labs., v. 35, p. I77, P1. 5, flgs. 12-14. Cooper (part), 19^7, Jour. Paleontology, v. 21, no. 2, p. 9I1 Pl. 20, figt. 4-6 (not figs. 7-10). Elias, 1956, Petroleum Oeology of southern Oklahoma: Am. Assoo. Petrol. Oeol., •. 1, p. 115, Dl. 2, figs. 1-6? Biechoff, 1957» Htts. Landttamt. Bodenf., Abhl., Hf. I9, p. I9, pl. 2, 35 figs. 7a, b. Cavusgnathus cristata var. grandis Elias, I956, Petroltum Qeology of southern Oklahoma: Am. Assoc. Petrol. Qeol., v. 1, p. 115, pl. 2, figs. 12-11^. Description: Oral view.—Platform long, narrow, sharply pointed posterior end; perpendicular siaes, outer parapet nearly straight, inner paraptt straight in tht anterior half and regularly convex to posterior end; Daranets transversely ridged becoming obsolescent into the trough; trough deep, narrow, faintly sinuous, increases in depth toward anterior end where it is open; blade denticles largt, even on inntr sidt, txpanded on outer side; median carina at posterior tnd of troup;h. Lateral vitw.--Oral margin of both parapets level, becoming convex near posterior end, mlnutely dentate; blade oomposed of six to eight denticles with irregular to regular- ly oonvex oral outline, length of blade greater than one- thlrd length of speclmen, approximately one-third of blade frtt; anterior end of inner paraptt trunoatt. Aboral vitw.—Navel of moderatt dtpth, tymmttrical to eubsymmttrical, extending only pert way to tht posttrior, Itaving tht posterior fourth of the aboral margln sharp- edged; anterior fourth sharp-edged. 36 Remarks: Length of figured speoimens is 1.42 and I.25 mm. Similar in all respects to the holotypt. Occurrence: Localities 1, ?, 3 and 5. Repository: Illinois State Qeologioal Survey l4p-2 and 14P-3 (hypotypes). CAVUSQNATHUS UNICORNIS Youngquist pná Miller Plate I, Figures 3 and 4 Cavusgnathus unicornis Youngquist and Miller, 1949i Jour. Paleontology, v. 23, no. 6, p. 619, pl. 101, figs. 18-23. Rexroad, 1957, Illinois Qeol. Survey Rept. Inv. 199, p. I7, pl. 1, flg. 7. Rexroad, I958, Illinois Qeol. Survey Rept. Inv. 209, p. 17, pl. 1, figs. 6-11. Cavusgnathus cristata Branson and Mehl, Cooper (part), 1947i Jour. Paleontology, v. 21, no. 2, p. 9I, figs. 7-IO. Description: Oral view.—Outer narapet convex outvard, inner parapet straight to slightly convex outward; both parapete crenulated along oral margins; blade aligned with outtr parapet, slight outward curve near anterior, bladt more than one-third total length of speclmen, denticles com- pressed laterally; trough deep. Lateral view.—Entire specimen gently arched, outer parapet hlgher than inner, posterior end rounded; blade com- 37 posed of six denticles, horn-like appearance of posterior- mott denticle, larger and higher than other dentioles, rt- maining dentlcles fused nearly to their aplces and deortast in size anteriorly, anterlor one-fourth of blade free. Aboral view.—Navel of moderate deoth, asymmetric, lanceolate-shaped outline, point reachlng posterior tip, inner lip with greattr flare, whioh extends farthtr anttrior ly from navel along otherwise sharp aboral margin. Rtmarks: Length of figured specimen is .57 mm.; mature form. Similar In all respects to the holotype. Occurrence: Localities 1, 2, 3, ii, 5 and 6. Rtpository: Illinois State Qeological Survey, l4p-l^ (hypotypt). Family PRIONIODONTIDAE Bassler, 19?5 Subfamily PRIONIODONTINAE Bassler, I925 Oenut QENICULATUS Hass, I953 Type species: Polygnathus? olaviger Roundy OENICULATUS cf. Q. CLAVIOER (Roundy) Plate I, Figurt I5 Polygnathus? olaviger Roundy, I926, U. 3. Qeol. Survey Prof. Paptr l46, p. 14, pl. 4, figs. la-c; 2a, b. 3í _Prioniodus htaldi Roundy, 1926, U. S. Qeol. Survty Prof. Paper l46, p. 10, pi. k, figs. 5a, b. Prioniodus sp. D Roundy (part), I926, U. S. Qeol. Survey Prof. Paptr l46, p. 11, pi. k, figs. l^a, b (not fig. 12). Euprioniodina? sp. Branson and Mehl, 19ÍII, Denison Univ., Sci. Lab., Bull., V. 35, p. 172, pl. 5, fig. 15. Baotrognathus clavjger (Roundy), Branson and Mehl, 1^41, Jour. Psleontology, v. I5, p. 99. BactrognathuB inornata Branson and Mehl, 194l, Jour. Paleon- tology, V. 15, p. 100, pl. 19, figs. 14, 15. Geniculatus claviger (Roundy), Hass, 1953, U. S. Qeol. Sur- vey Prof. Paper 243-F, p. 77, pl. I5, figs. IO-19. Elias, 195^1 Petroleum Qeology of southern Oklahoma: Am, Assoc. Petrol. Qeol., v. 1, p. 121, pl. 4, figs. 8-21. Description: Because of the fragmental n^ture of Qenioulatus of. Q. claviger (Roundy) from the •'asstmblage-rone^* the fol- lowing dtscription is taken from Hats (15:77). Oral view.—A young specimen oonsists of a denticu- lated posterior bar that supports the main cusp, and a shorter, denticulated anterior bar that is Joined to tht inner side of the raain cusp. During ontogeny, through the accretion of lamellae, the posterior and anterior bare gradually evolved into a massive, geniculate, bar- like unlt. This unit is asymmetric, broadest at the vertex, and tapered toward the extremities; its denti- cltt art slightly curved and are generally located near- er the outer than the Inner side of the fossil. Other oharacteristics are more variable. Denticles may range from short to long, straight to curved, discrete to ap- prested, and peglike to toothlike. The main outp also 59 variet in sizt and shape. Sharp edgtt generally divide tht outp into a emaller, even, inner side and a larger, txpandtd outer sidt. In transvtrst stotion, the antt- rior and posterior bars of a young speoimen are hlfcher than wide and their convex sides art broadtst at or bt- low midheight; the bart of a mort mature specimen art completely merged to fcrm a genioulate unit whlch, at the vertex, is several times wider than high. Lateral view.—Aboral sidt of unit slightly arched. Summit line of unit dentate, incised, and irregular. Aboral vlew,—Aboral side of unit tends to be set off from remainder of fossil by a continuous ridgt; area thus enclosed may be exosvated. PUIP oavity tends to be largt, and triangular to elliptioal in outline. Remarks: The figurtd specimen exhibits the matsive bar-likt oharacter, broadest toward the vertex, and tapered toward the extremity; Its denticles are slightly curved. In tht lateral view the abcral eide of the unit ie slightly arohed. The aboral side of the specimen is set off from the rtmain- der of the fossil by a continuous ridge that is shallow and broadly excavated. The specimen is similar to the holotypt. Oocurrence: Localititt 2, 4 and 6. Rtpository: Illinois State Geological Survey, l4P-5 (hypotypt). 40 Family IDIOQNATHODONTIDAE Harrit and Hollingsworth, I933 Subfamily IDIOQNATHODCNTINAE Harris and Hollingsworth, I933 Otnus 0NATH0DU3 Pander, I856 Type speoies: Qn/gthodut Mosquensis Pander GHATHCDUS BILIUZJWJO (Rcundy) Plate I, Figure 7 Polygnathus bilineata Roundy, I926, U. S. Qeol. Survey Prof. Paper l46, p. I3, pl. 3, figs. lOa-c. Poly,^nathuB texana Roundy, I926, U. S. Qeol. Survey Prof. Paptr 146, p. 14, pl. 3, figs. l^a, b. Onathodus bilineatus Roundy, Cooper, 1939» Jour. Paleontol- ogy, V. 13, p, 388, pl. 1|2, figs. 59, 60.? Onathodus pustulosus Branson and Mehl, Hats, 1953» ^* ^. Otol. Survey Prof. Paper 243-F, p. 78, Onathodus bilineatus (Roundy), Hass, 1953, U. S. Oeol. Sur- Tty Prof. Paper ?43-F, p. 78, pl. lU, figs. 25-29. Eliat, 1956, Petroleum Qeology of southern Oklahoma: Am. Assoo. Petrol. Qeol., v. 1, p. II8, pl. 3, figs. 23-29. Stanley, 1958, Jour. Paleontology, v. 32, p. 464, pl. 68, fig. 7. Gnathodus cf. bilineatus Roundy, Eliat, 195^, Petroleum Otology of southern Oklahoma: Am. Assoc. Petrol. Geol., V. 1, P. 11*» Pl. 3. fig. 40.? Onathodus (Harltonodus) bilineatus (Roundy), Elias, 1959» 41 Oeology of the Ouachita Mountains: Dallas and Ardmore Oeo- logical Societies, p. 1I15, pi. 1, figs. 10, 11, 16 and 17. Description; Oral view.—Axis essentlally straight; narrow parapet-like inner side of platform parallels oarina; postt- rior two-thirds of outer margin of platform convex inward, anterior one-third concave inward; carina and platform range in length up to, but generally Ittt than, one-half length of tpecimen; anterior portion of inner platform bears trans- verse ridges, posterior portion bears nodes and rldges; out- er side of platform sub-rectangular in outline, but expandtd anteriorly; nodes on upper surface arranged in concentric rows about the apex of the expanslon. Lateral view.—Carina down-curved posteriorly, denticles broad, low nodose; blade hlghest near anterior end, denticles laterally compressed, fused nearly to apicet. Inner lattral view.—Inner margin about samt height as carina; anteriorly it termlnates sharply along a line in- olined about 75 or 80 degrees nosteriorly (using line of aboral edge of bladt as reference); laterally flaring lip along aboral margln; aboral profile concave. Outer lateral view.—Detp outer lateral platform unites wlth carlna at about mid-height of blade; strongly down-curved near anterior edge of platform, aboral profilt conoave. kZ Aboral view.—Outline of cup atymmetric, aptx ntar anterior end, marktd groove extends along otnervlse sharp tdgt of blade to itt anterior end. Rtmarks; Similar in all rtspects to the holotypt. Occurrence: Localitits 2 and 3. Repository: Illinois State Oeologioal Survey, l4P-6 (hypotypt). ONATHODUS M0D0CEN3IS Rexroad Plate I, Figures 5 and 6 Onathodus modocensis Rexroad, I957, Illinois Qeol. Survty Rept. Inv. 199, p. 30, pl. 1, figs. I5-I7. Rexroad, I958, Illinols Qeol. Survey Rept. Inv. 209, p. 1, figs. 1 and 2. Qnathodus (Harltonodue) bilineatus (Roundy), Elias, 1959» Oeology of the Ouachlta Mountains: Dallas and Ardmore Qeo- logical Societies, p. l45, pl. 1, figs. 8 and 9. Description: Oral view.—Axls essentially straight; narrow parapet-like inner side of platform parallels carina, except that both curve slightly to unite In a point at the postt- rior end of si^ecimen, both range in length up to, but gener- ally lesB than, one-half length of speoimcn; inner margin bears single row of nodes and is set off from oarina by ttraight, narrow trough; outer side of platform sub-reotan- ••3 guler to ttmicircular in outline, but expanded anteriorly; gentrally nodes on upper surfaoe longitudinally llnearly arranged, but may be irregularly disposed. Lateral view.—Carina of a young sptoimen strongly down-curved posteriorly, that of a mature one is gently tapertd downward; denticles broad, low nodose; blade highest near anterior, decreatts regularly in height posteriorly; denticles about eight to twelve, laterally compressed, fuetd nearly to apices; anterior end of blade convex, aboral edgt Btraight. Inner lateral vitw.—Inner raargin of platform about sarae height as carina of a mature specimen, carlna higher than inner margln of platform of a young specimen; truncattd anteriorly along a line inclined about 80 degrees posterior- ly (using line of aboral edge of blade as reference); face rounded, laterally flaring lip along aboral margin; aboral profile concave. Outer lateral view.—Shallow outer lateral platform unites wlth carina at about mid-height of blade, aboral pro- flle conoave. Aboral view.—Outline of cup asymmetric, apex of cup ntar anterior end, marked groovt extends along otherwist tharp adgt of blade to its anterlor end. Rtmarks: Similar in all respects to the holotype. 44 Occurrence: Localitits 2, 3, h and 5. Rtpository; Illinois State Qeological Survey, 14P-7 and 14P-8 (hypotyptt). Family COLEODONTIDAE Branson and Mthl, l^kk Subfamily LIQONODININAE Hatt, I959 Oenus LIQONODINA Bassler, I925 Type specieB: Ligonodina pectinata Bassler LIQONODINA OBUNGA Rexroad Plate I, Figure 21 Ligonodina obunca Rexroad, 1957, Illinois Geol. Survey Rer^t. Inv. 199, p. 32, pl. 1, figs. 22, 23, Rexroad, I958, Illlnois Oeol. Survey Rept. Inv. 209, p. 21, pl. 3, figs. 7. «. Ligonodina sp., Youngquist and Miller, 1949, Jour. Paleontol- ogy, V. 23, no. 6, p. 620, pl. 101, figs. 12, 13. Description: Posterior bar long, thin, nearly straight; aboral margin of bar truncated, expanded at anterior end; outer lateral llp present; attacl'iment present toward ante- rior end of inner face; denticles of bar small discrete, widtly spaced, laterally compressed, thicker and wider at iMitt. Terminal fang long, slender, recurved with grtatett curvature near base, somewhat oompresBed laterally, upper half slightly twisted. Infero-lateral procett short, di- rected tharply downward, inward, and backward; aboral edgt mtdially grooved; procttt beare fnur discrete denticles, tht proximal one nearly round in cross section, the distal ont oompresstd in plane of process; In a vtrtical plane, vith posterior bar horizontal, the potterior-infero-lateral pro- cess angle is approximately 50 degrets. Rtmarks: Length of figured specimen is .60 mm., height of fang is 1 mm., length of infero-lateral process is .37 ••• Similar in all resrects to the type srecies. Occurrence: Localities 1, ?, 3» 4, 5 and 6. Rtpository; Illinois State Qeological Survey l4p-9 (hypotype). Subfamily LONCHODININAE Hats, 1959 Oenus LONCHODINA Bassler, 19?5 Type sptcles: Lonchodina typicalis Ulrich and Bassler LONCHODINA FURNI3HI Rexroad Plate I, Figures 16 and I7 Lonohodina furnishi Rexroad, 195*» Hllnois Geol. Survey Rtpt. Inv. 209, p. 22, pl. 4, figB. 11-13. 46 Description; Arched and bowtd unit, limbs thioktst at aptx and thinning distally. Posterior limb the shorter, about three-eights the length of anterior limb, bowed slightly in- ward, bearing one (probably two, limb inoomplete) small, dÍBorete denticle oompresBtd laterally. Anterior limb tht longer, inclined downward and slightly outward, bearing thret (probably five, limb inoompltte) laterally oomprtSBtd dentioles, recurved, sharp tdges fore and aft, edges in mid- line of tach llmb; baee of apioal denticle expanded into flaring lipt about the subapical pit, inner lip flaring in and posteriorly, outtr lip flaring out and anteriorly, re- sulting in a pit which is nearly oval In outline with long- ttt axis obllque to axis of posterior bar. Aborally, median groove extendt from apical pit to extremities of limbt. Remarks: Similar In ell respects to the holotypt. Occurrence; Localities 3 *nd 5. Rtpository; Illlnois State Oeological Survey 14P-10 (hypotype). ^ EXPLANATION OF PLATE I (Continued) Figurt 1^» 17 Lonchodina furnishi Rexroad; outer lateral and aboral /iews of young speoimen (5-5). 1* Neoprioniodus scitulus (Branson and Mehl); inner lateral view of mature, incomplete specimen (1-5)« 19 Ogarkodina oompreBBa Rexroad; inner iateral view (2-13). 20 Neoprloniodus cf. ]J. singularis (Hasa); inner lateral view of inoomplete speoimen (5-5). 21 Ligonodlna ohunca Rexroad; inner lateral view of mature specimen (I-3). 22 Neny^rioniodiiw T A go (Haes); outer lateral view of incomplete specimen (3-I6). 23, 2li Lonohodins cf. L. paraolarki Hass; outer and inntr lateral views (2-5 and I-3). si TPriivntoGlCAL CULLÍiUti 50 LONCHODINA cf. L. PARACLARKI HasB Plate I, Figures 23 and 21^ Lonchodina paraclarki Hass, I953, U. 3. Otol. Survty Prof. Paper 243-F, p. 83, pi. 16, figt. 15, 16, Stanley, 1958, Jour, Paleontology, v. 32, p. 1^68, pl, 67, fig. 1. Lonchodina cf. L. paraolarki Hats, Rexroad, I958, Illinois Oeol, Survey Rept. Inv. 209, p. 22, ol. U, fip'f'. U, 5. Description: Main cusp long, pointed, and direottd forward, with greatest degree of curvature near the base. Two sharp edges divide the maln ousp into a largtr inner side and a tmaller outer one. Outer sldt of ousp broadly convtx through-out its entire length. Inner aide convex, its basai portlon expanded posteriorly. Anterior sharp edge of cusp oontinuouB with midline of anterior bar. Anterior bar Btraight, about the same length as the maln cusp, and, with reference to posterior bar, is directed outward and downward. Anterior bar of young specimen fragile and ocmprttttd; that of a mature one is stout, lilgher than wlde, and is tapered to a pcinted distal extremity. In transverst tection, thit bar ifl broadest along aboral siae; its lateral eidts con- Ttrgt orally and mtrge Into the denticles. Anterior bar of maturt form supports fivt denticlet which are discrete, irregularly set, curved pcsteriorly, pointed, oomprttttd in 51 plant of bar, and biconvex In section. Posterior bar it inoompltte; it supportt two dtnticles, but probably support- ed four or five, which though normal to bar curve toward outer side of fossil. Posterior bar twisted, with referenct to anterior bar, is gently ourvtd inward and directed down- ward; other characteristice of posterior bar and Its denti- clet similar to those of dentlculated anterior bar. Aboral side of fossil broadest beneath main cusp from where it ta- pers to pointed extremities. Midline of aboral side grooved. Pulp cavlty occupies entire under side of main cuep and is located mainly on inner side of midline of fossil. Rtmarks: The specimens from the ••attemblage-zone" are sim- ilar to the holotype of I^. paraclarki Hass. The a; ical den- ticles of the ••aesemblage-zone*^ specimens are slightly Bhorter and broader and the number of bar denticies is greater than those of the holotype. Occurrence; Localities 1, 2 and 6. Repository: Illinois State Geological Survey l4P-ll and 14P-12 (hypotypes). METALONCHODINA Bp. Plate I, Figure 12 Metalonchodina sp., BranBon and Mehl, 1941, Jour. Paleontol- 52 ogy. V. 15, pi. 19, fig. 33^ Metalonchodina sp. A, Hass, 1953, U. S. Qeol. Survey Prof. Paper 2U3.F, p. 85, pi. 16. fig,. 17, lí. DtBcription: The figurtd speoimen is inoomplete. It is compostd only of the anterior bar and apical denticle. An- terior bar is thickest adjacent to the pulp cavity, com- pressed and pointed at the dittal extremity; in lattral vlew this bar is curved downward. Anterior bar suDPorts one large denticle which is directed slightly forward, curvtd inward, pointed, compressed, and biconvex in transverse sec- tion, This denticle is about three times as large at main ousp, its inner side, especially adjacent to the main cusp, Í8 muoh larger than its outer side. The posterior bar waa probably flexed downward about 80 degrees with referenoe to anterior bar. Main cusp curved inward, round in transverse sectlon, inner slde Is enlarged especially in the basal por- tion. Aboral slde of fnesil with narrov groove along mid- line. Apical pit deep, coniform, and located chiefly on inntr sidt of midline, Rtmarks; The flgured specimen is similar to Metalonchodina 8p. Pranson and Mehl. Occurrenoe: Locality 2. 53 Rtpository; IllinoÍB State Qeological Survty 14P-13 (hypotype). family COLECDONTIDAE Branson and Mehl, I9UU Subfamily NEOPRIONIODONTINAE Hass, I959 QenuB NE0PRI0NI0DU3 Rhodes and Muller, I956 Typt species: Prioniodus conjunctus Ounnell mOPRIONIODUS LIGO (Hass) Plate I, Figure 22 Prioniodus peracutus Hinde, Roundy (part), I926, U. 3. Qeol. Survey Prof. Paoer l46, p. 10, pl. U, figs. 7, 8 (not fig, 6). Prioniodus ligo Hass, 1953, U. S. Oeol. Survey Prof. Paper 243-F, p. 87, pl. 16, figs. 1-3. Elias, 1956, Petroleum Oeology of southern Oklahoma: Am. Assoc. Petrol. Qeol., v. 1, p. 109, pl. 2, figs. 16-18. PrionioduB cf. P. ligo Hass, Elias, 195^, Petroleum Qeology of southern Oklahoma: Am. Assoc. Petrol. Qeol., v. 1, pl. 3, flg. 51. Neoprioniodus ligo (Hass), Elias, 1959» Geology of the Ouachita Mountains: Dallas and Ardraore Geologioal Societies, p. 150, pl, 2, figs, 12-14. 5»* Description: Posterior bar curved inward; its aboral por- tion is beveled and finely lined by free edges of lamellat compoBÍng fossil, more conspicuous on inner side. In trans- vtrte section, bar is higher than wide, with the inner sidt thicker than the outer. Denticles normal to bar, closely set, Blightly ourved Inward, pointed, and oioonvex in sec- tion wlth inner sidt thioker than outer. In lateral view, the main cusp (incomplete), together with the anticuep (in- complete), forms a masBÍve, triangularly shaptd unit that ÍB pointtd at the extremities, broadest and thickeet adja- oent to tht posterior bar, and bowed inward slightly. Cutp sharo-edged fort and aft and nearly straight; aboral side of outp slightly convex. Inner side of cutp adjacent to tht anterior edge iB compressed, but posterior to this area the inner side is thicker; outer eide of cusp evenly round- ed. The beveled and striated characteristioB of the aboral portion of the posterior bar probably oontinued to the tip of the anticusp. Aboral eide of fosBÍl grooved along mid- line. Pulp cavity small, pit-like, located at Junction of posterior bar and cusp. Rtmarkt: Similar in all respects to tht holotype. Oocurrence: Localitiet 3 ^^^ ^. 55 Rtpository; Illinois Statt Oeological Survey, l4P-l4, (hypotypt). NEOPRIONIODUS iiCITULUS (Rriinson and Mthl) Platt I, Figure l8 Prioniodus scitulus Braneon and Mehl, 1^40, Denison Univ. Bull., Jour. Sci. Labs., v. 35, p. 173, pi. 5, figg. 5, 6. Cooper, 1947, Jour. Paleontology, v. ?1, no. 2, p. 92, pl. 20, figs. 1-3. Elias, 1956, Petroleum Geology of southern Oklahoma: Am. Assoc. Petrol. Oeol., v. 1, p. 109, pl. 2, figs. 9, 10. Neoprioniodus soitulue (Branson and Mehl), ^exroad, I957, Illinois Geol. Survey Rept. Inv. 199, p. 35, pl, 2, figs, 22, 26. Rexroad, I958, IHinois Oeol. Survty Rept. Inv, 209, p. 23, pl, 5, figB. 10-14. Elias, 1959, Qeology of tht Ouaohita Mountains: Dallat and Ardmore Qeological Soci- eties, p. 151» Pl. 2, figs. 6, 7« Neoprioniodus striatus Rexroad, 1957» IHinols Geol. Survty Rept. Inv. 199, p, 35, pl. 2, figc, 11, 12. Neoprioniodus cassilaris (Branson and Mehl), Eliae, 1959» Otology of the Ouaohita Mountains; Dallas and Ardmore Geo- logioal Societies, p, I53, pl, 2, figs. 20, 21. Description: Posterior bar straight, slightly conoavt in- ward, thort thin; aboral edge truncated and mtdially 56 groovtd. Bar dentlclts slightly inclined posteriorly, lat- erally compressed, sharp-tdgtd fore and aft, txceptionally long and slendtr, gradually tapering to a sharp point; sntlousp sharply polnted, extends well below the aboral tdge of the bar; viewed laterally, anterior edge presents a regular, gently convex outline. Pulp cavity beneath tht fang shallow, narrow, with sharp lateral tdgtt, inner lip with greater flare; prominent attachraent scar along postero- aboral margin of antiousp. Rtmarks: Similar in ell respeots to the syntypes. Occurrence: Localities 1, 2, 3, 5 and 6. Rtpository: Illinois State Qeological Survey 14P-15 (hypotype). NEOPRIONIODUS of. N. SINQULARIS (Hass) Plate I, Figure 20 Prioniodus singularis Hass, 1953, U. 3. Qeol. 3urv<»y Prof. Paper 243-F, p. S6, pl. 16, fig. 4. Slias, 1956, Petroleum Qeology of southern Oklahoma: Am. ABSOC. Petrol. Oeol., v. 1, p. 112, pl. 2, fig. 15. Prioniodus cf. P. singularis Hass, Elias, I956, PetroltuM Oeology of southern Oklahoma: Am. Assoc. Petrol. Geol., v. 1, p. 112, pl. 2, fig, U5. 57 Neoprioniodus singularis (Hatt), Stanley, I958, Jour. Paltontology v. 32, p. 1171, pi. 66, figfl. 2, 3. DeBcription: Posterior bar oompressed, shorter than main ouflp, adjacent to which It is fltxtd inward approximately 25 degrees. In lateral view bar it highttt at the anterior end from which it tapers to a pointed aistal extrtmity. Dtnticles of the bar gradually decrease in size posteriorly; they are closely set, directed slightly forward, curved in- ward, pointed, and biconvex in section, With reference to the posterior bar the raaln cusp Is directed forward; in lateral view it probably (inooraplete) was an elongate, tri- angularly shaped unit which wat pointed at the extremitiet, it is broadest and thiokest adjacent to the posterior bar, and bowed inward slightly. The cusp is sharp-edged fort and aft and nearly straight; ataoral side slightly convex. In transverse section the cusp is biconvex, inner sidt thicker than outer. Denticle proximal to cusp is, in part, fused with cusp, Aboral side of fossil grooved along the midline. Pulp cavity very sraall, located near the potteri- or end of the main cusp. Aboral portion of lateral sides of fossil beveled and lined by free edges of lamellae of foflsil. Above the pulp cavity the above-mentioned beveled area is conspicuously arohed. 5« Rtmarks: The distal portlons of the figured specimtn are inoompltte but it is similar to tht holotypt. Tht postt- rlor bar is flexed Inward about 25 degrttt and tht arohing of tht fret edgtfl of lamellat it flomtwhat more conspiouout on tht outer side of the fossll, Thttt ftaturtt are oon- trary to tht desoription of ^i. singularis (HSBB) but prob- ably fell within the range of individual variation. Ocourrence; Locality 5, Rtpository: Illinois State Geological Survey, l4P-l6 (hypotype). Family PRIONIODONTIDAE Bassler, I925 Subfamily PRIONIODONTINAE Bassler, I925 Oenus OZARKODIIÍA Branson and Mehl, I933 Type specitfl: Ozarkodina typica Branson and Mehl OZARKODINA COMPRESSA Rexroad Platt I, Figurt 19 Ozarkodina compresfla Rexroad, 1957, Illinois Geol. Survty Rtpt. Inv. 199, p. 36, pl, 2, figs. 1, 2, Rexroad, 195^» Illinols Oeol. Survty Rtpt. Inv. 209, P. 24, pl. 6, figs. 1, 2. 59 Dtfloription: Blade-likt unit, thin, arched and bowed, ttrongtr bowing of posterior limb; anterior limb with tight futtd dtntioltt, tlightly oompresstd lattrally; twtlvt dtn- ticlet on posterior limb, mort oompretatd than anterior dentlcles, inclined etrongly posteriorly; dtntiolet vary in tixt. Apioal dontiole twict width of othtrs, longer, ta- pers to point, Inclined potteriorly. Navtl of moderatt dtpth, atymmttric elliptioal outline, lipt flared flllghtly, outtr lateral lip flartd more, but it shorter; longitudinal groove extendfl to ende of specimen. Remarks: The only discrepancy between the figured speoimtn and the holotype ia the number of dentioles on tht posterl- or bar. Tht "atttmblagt-zone^* tpecimen has mort denticlet on tht poflterior than the anterior bar. Rexroad'fl dttorlp- tion notet two or three lesfl denticlee on the Dosterior bar. Ooourrence; Localitiefl 2 and 3. Rtpoflitory: Illinois State Qtologioal Survty, l4P-17 (hypotype). 60 Subfamily 3PATH00NATH0D0NTINAE HasB, I959 Oenufl 3PATH0ONATH0DU3 Branton and Mehl, 194l Type flpeoitt: Spathodufl primufl Branson and Mehl 3PATH0GNATH0DU3 CAMPBELLI Rexroad Plate I, Figures I3 and l4 Spathognathodus oampbelli Rtxroad, I957, Illinois Otol. Survey Rept. Inv. 199, p. 37, pl. 3, figs. 13-I5. Rexroad, 195^» Illinois Oeol. Survey Rept. Inv. 209, p. 25, pl. 6, íig. 9 Dtecription: Blade delioate, slightly bowed in posterior two-thirds, composed of 19 laterally compressed denticles; dtntlclet tubequal in size, each from distinct germ dtntl- ole, nearly vertical in anterior half, but tend to incline poflteriorly in pcsterior half. In laterai vitw, oral mar- gin orenulate, convex, oonvexity increatlng poflteriorly; blade dietinctly thinner aboral to horizontal line that runfl the length of speoimen; lateral lips of navel thln; navel curved and atymmttric, pointed posteriorly, exttnding to rtar of sptoimtn, Ittt pointed anteriorly, extendtd at groove along aboral edge of blade; outer llp flared uniform- ly, inntr lip with greatest flare enteriorly, greater part of navel sllghtly posterior to middle of speoimen. 61 Remarks: Length of figurtd specimen it .50 mm.; mature form. Similar in all retpeots to the holotypt. Occurrence; Locality 5. RepoBitory; Illinois State Oeological Survey, l4P-l8 (hypotypt). SPATHOGNATHCDUS cf. 3. COMMUTATUS Branson and Mehl Plate I, Figure 11 Spethognethodus commutatus Branson and Mehl, 19^1, Jour. Paleontology, v. 15, no. 2, p, 98, pl. 19, figs. 1-4, Spathognathodus cf. ^. commutatus Branson and Mehl, Rexroad, 1957, Illinois Oeol. Survey Rept. Inv. 199, p. 38, rl. 3, figs. ?3, 24. Rexroad, I958, Illinols Geol. Survey Rept. Inv. 209, p. 26, pl. 6, fig. 8. Desoription: Axis of blade slightly curved inward, mort strongly curved in potterior one-third. In lateral view, oral edge nearly straight in its anterior half and regularly convex in its posterior half; blado thin anterlorly with a slight tendency to thioken posteriorly; oral edge composed of nine denticles, subequal in size, each from distinot germ denticle, nearly vertical in anterior half, but inclined posteriorly in posterior half. In aboral view, length of navel is approximately two-thirds length of speciraen; lat- 62 eral lipe of navel thin; navel curvtd and atymmetrio, pottt- riorly pointed, extendtd at groove along aboral edge of bladt; inner lip flared uniformly, outer lip with grtattflt ^art anteriorly; navel deepest near anterior end. Rtmarkt: Rexroad (1,2) reported that Cheettr speoimens havt a thinner lipped, proportionately longer navel, and fewer dentiolts than do Branson and Mehl's syntyptt from the Pitkin Limestone, The wrlter finds the sace relation- shipfl to be true with specimens from the '•apsenblage-zont'* and ftels that theee differences fall within the range of individual variation. About ten percent of the speoimens identified by tht writtr at Spathognathodus cf. £. commutatus Branson and Mehl tetm to be typical Pitkin Liraestone forms. They are thick lipped and appear to have a greater number of denticlee; however, the fragmental nature of these specimens does not permit an exact identification. Oocurrence: Looalititt 2, 3» ^ ^^^ 5» Repository: Illinois State Geological Survey, l4p-19 (hypotype).