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University Microfilms

A Xerox Education Company 72-21,027

VOTAW, Robert Barnett, 1939- œNODONT BIOSTOATIGRAIW OF IHE BLACK RIVER GROUP (MIDDLE ORDOVICIAN) AND EQUIVALENT ROCKS OF THE EASTERN MIDCONTINENF, NORTH AMERICA.

The Ohio State Ifeiversity, Ph.D., 1972 Geology

University Microfilms, A XEROX Company, Ann Arbor, Michigan

THIS DISSERTATION HAS BEEN MICR0FII2CD EXACTLY AS RECEIVED. CONODONT BIOSTRATIGRAPHY OF THE BLACK RIVER GROUP

(MIDDLE ORDOVICIAN) AND EQUIVALENT ROCKS OF THE

EASTERN MIDCONTINENT, NORTH AMERICA

DISSERTATION

Presented in P artial Fulfillm ent of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University

By

Robert Barnett Votaw, B.S., A.M.

* * * * *

The Ohio State University 197.1

Approved by

A d v is e r Department of Geology PLEASE NOTE:

Some pages may have

indistinct print.

Filmed as received.

University Microfilms, A Xerox Education Company ACKNOWLEDGMENTS

The author gratefully acknowledges Penrose Bequest Research

Grant No. 1430-70 from the Geological Society of America, which supported field work during the spring and summer of 1970. The

Friends of Orton Hall Fund provided additional funds for transportation and paid the cost of producing the plates. Cominco American, Inc., through Mr. Stewart Jackson, donated a complete core of the Lexington,

Tyrone, Oregon, and Camp Nelson Limestones from Mason County, Kentucky, a 545-foot segment of this core was sampled for this study. Dr. Stig

BergstrBm, of The Ohio State University, provided the author insight into Appalachian correlations, conodont systematics and stratigraphie evaluation, and the author benefited greatly from these observations.

Dr. Walter C. Sweet, of The Ohio State University, suggested the project and made available to me extensive type and undescribed col­ lections at The Ohio State University. His constant assistance, able field partnership and provocative discussions are deeply appreciated.

Finally I would like to thank my wife, Barbara, for her spirited field assistance, toleration of my frustrations, and calming influence. October 19, 1939 . . . Born, Cincinnati, Ohio

1962 ...... B.S., Indiana University, Bloomington, Indiana

1962-1964 ...... Teaching A ssistant, Department of Geology, Indiana University, Bloomington, Indiana

1964 ...... A.M., Indiana University, Bloomington, Indiana

1964-1968 ...... Petroleum Geologist, The Standard Oil Company of California, Bakersfield, California

1986 ...... Teaching Associate, Department of Geology, The Ohio State University, Columbus, Ohio

1969-1971 ...... National Science Foundation Trainee, The Ohio State U niversity, Columbus, Ohio

PUBLICATIONS

Votaw, Robert, and others, 1966, Cross-bedding in the Salem Limestone of southern Indiana: Sedimentology, Vol. 6, pp. 95-114, 12 figs., 3 t a b l e s . TABLE OF CONTENTS

Page

ACKNOWLEDGMENTS...... i i

VITA ...... i i i

LIST OF TABLES ...... v i i

LIST OF FIGURES ...... v i i i

INTRODUCTION ...... 1

METHODS OF STUDY ...... 3

DESCRITPION OF SAMPLE L O C A L IT IE S ...... 6

PREVIOUS STUDIES OF THE BLACK RIVER GROUP...... 10

CONODONTS OF THE BLACK RIVER GROUP AND EQUIVALENT STRATA . . . 20

Fibrous Conodont-elements

Laminar Conodont-elements

. The "zone" of Phragmodus inflexus

CORRELATION OF THE SECTIONS STUDIED...... 33

CHAMPLAINIAN CORRELATIONS BY OTHER FOSSIL GROUPS ...... 37

CORRELATION WITH OTHER AMERICAN S E C T IO N S ...... 40

MIDDLE ORDOVICIAN CORRELATION COMPARISONS ...... 45

SYSTEMATIC PALEONTOLOGY...... 52

Genus ACODUS Pander, 1856 52

A codus m u ta tu s (B ran so n and M ehl) ...... 52

Genus ACONTIODUS Pander, 1856 54

Acontiodus alveolaris Stauffer ...... 55

Genus APPALACHIGNATHUS V otaw , n . g e n ...... 56

iv Appalachignathus delicatulus Votaw, n. sp...... 56

Genus BELODELIA ( E th in g to n ) , 1959 , ...... 60

Belode11a niger (Serpagll) ...... 60

Genus BELODINA E th in g to n , 1959 ...... 64

Belodina compressa (Branson and M ehl) ...... 64

Genus BRŸANTODINA. S t a u f f e r , 1935 ...... 66

Bryantodina? abrupta (Branson and Mehl) ...... 66

Genus CHIROGMTHUS B ran so n and M ehl, 1933 67

Chirognathus monodactylus Branson and Mehl ...... 68

Genus CURTOGMTHUS Branson and Mehl, 1933 72

Curtognathus robustus (Branson and Mehl) ...... 73

Curtognathus typus Branson and Mehl ...... 76

G enus BISTACODUS H in d e , 1879 ...... 85

Dlstacodus falcatus Stauffer ...... 85

Genus DREPANOISTODUS L in d strB m , 1955 ...... 87

Drepanolstodus suberectus (Branson and Mehl) ...... 87

Genus ERISMODUS Branson and Mehl, 1933 ...... 88

Erismodus radicans (Hinde) . 89

Genus "OISTODUS" Pander, 1856 95

"Oistodus" venustus Stauffer ...... 97

Genus OULODUS Branson and Mehl, 1933 ...... 98

Oulodus serratus (Stauffer) ...... 103

Genus PANDERODUS E thington, 1959 ...... 106

Panderodus gracilis (Branson and Mehl) ...... 106

Panderodus panderi (Stauffer) ... 109

Genus PHRAGMODUS Branson and Mehl, 1933 109

Phragmodus cognitus Stauffer ...... 112 Phragmodus inflexus S ta u ffe r ...... 113

Phragmodus tortus Sweet, ms...... 1 1 4

Phragmodus undatus Branson and M e h l ...... 116

Genus PLEGTODINA Stauffer, 1935 118

Plectodina aculeata (Stauffer) ...... 118

Plectodina n. sp., V o t a w ...... 121

Genus POLYPLA.COGNA.THUS Stauffer, 1935 123

Polyplacognathus ramosus Stauffer ...... 123

Genus SCANDODUS Lindstrbm, 1955 ...... 124

Scandodus superbus Votaw, n. sp...... 126

Genus "TRUCHEROGNATHUS" Branson and M e h l ...... 132

"Trucherognathus" sp., V o t a w ...... 132

APPENDIX ...... 134

PLATES ...... 150

REFERENCES CITED ...... 163 LIST OF TABLES

Page

1. The Black River F auna ...... 134

2 . S p e c ie s K e y ...... 137

3. Key to the Sections Studied ...... 138

4. Distribution and Frequency of Conodont-elements by

Species and Sample Locality ...... 139

5. Frequency of Conodont-elements by Species and Sample . . . 141 LIST OF TEXT-FIGURES

Page

1. Index Map of Sample L ocalities ...... 5

2. History of Black River Group Nomenclature ...... 12

3. Comparison of Distribution of Belodina and Scandodus . . . 28

4. Outline Drawing of Acodus mutatus ...... 53

5 . Outline Drawing o f Appalachignathus delicatulus ...... 57

6. Outline Drawing of Belodella niger ...... 62

7 . Outline Drawing o f Chirognathus monodactylus ...... 70

8 . Outline Drawing o f Curtognathus robustus ...... 74

9 . Outline Drawing o f Curtognathus typus ...... 83

10. Outline Drawing of Oulodus serratus ...... 99

11. Phylogeny of the genus Oulodus ...... 102

12. Four Species of Phragmodus ...... I l l

13. Two S p e c ie s o f P l e c t o d i n a ...... 120

14. O u tlin e D raw ing o f Scandodus su p e rb u s ...... 127

15. Comparison of the elements of Scandodus brevibasis, S.su p e r b u s .

and M ultioistodus ...... 128

16. Stones River Group, Central Basin, Tennessee In Pocket

17. Camp Nelson, Jessamine County, Kentucky In Pocket

18. Cominco ^erican Core CA-33, Mason County, Kentucky . In Pocket

19. Pan American Davidson Core, Richland County, Ohio . . In Pocket

20. Roaring Brook, East Martinsburg, New York ...... I n P o c k e t

21. Lowville Quarry, Lowville, New York In Pocket

viii 2 2 . Coboconk, Ontario ...... In Pocket

2 3 . Grand Cloche Island area, Ontario ...... In Pocket

24. Van D riest Core, Sheboygan County, Wisconsin .... I n P o c k e t

2 5 . Bony Falls, Delta County, Michigan ...... In Pocket

2 6 . Pikes Peak, Clayton County, Iowa ...... In Pocket

2 7 . Batchtown Quarry, Batchtown, Illinois In Pocket

2 8 . Correlation of the Sections Studied In Pocket INTRODUCTION

Th'i purpose of th is study is to describe conodont-elements from the Black River Group (Middle Ordovician) of New York and i t s la te r a l equivalents elsewhere in the eastern Midcontinent and to develop, if possible, a regional zonation of these rocks based upon conodonts.

Prior to this study, the Black River Group and presumably equivalent rocks had been correlated primarily on the basis of lithology. These correlation? are probably diachronous in part, because the succession of rocks that includes the Black River Group represents sediments deposited during a major transgression of the North American Mid­ continent, A further goal of this study is to investigate the distri­ b ution, morphology, and taxonomy of fibrous conodont-elements. These elements, which have been greatly neglected in the past, may provide assistance in zonation of the Black River Group and rocks of equivalent age.

This study continues investigations of Middle and Upper Ordovician rocks carried on a t The Ohio S tate U niversity fo r more than a decade,

Conodont faunas have previously been described from the type Edenian

(Sweet and o th e rs, 1959)» M aysvillian (Pulse and Sweet, I960), and

Richmondian Stages (Kohut and .Sweet, 19o3) and from th e type Trenton

Group (Schopf, 1965) and the Lexington Limestone of Kentucky, Ohio and

Indiana (Bergstrom and Sweet, 1965). The conodont-elements that form the basis of this study were derived from samples collected at l6 surface localities around the

margin of the eastern Mdcontinent, Core material from three different localities has helped to fill in some sample gaps in the area studied.

The collection localities and position of the core holes are shovm on

the Index Map (Text-fig. l). MSIHODS OF STUDY

Rocks presumed to be equivalent to the Black River Group in age

are dominantly limestone and surround the eastern Midcontinent in an

almost continuous outcrop. I t was ejqjected th a t these rocks would

be poorly productive of conodont-elements, thus 4- to o-kg, samples

were collected at 5-foot intervals from l6 previously described surface

sections. In addition, samples from three well cores provided control

in the interior of the studied area. Surface localities include

sections in the type areas of the Black River Group in New York (Young,

1943; Ross, I 9Ô4) and the Stones River Group in the C entral Basin in

Tennessee (Wilson, 1943, 1949). A section was also sampled at Limestone

Mountain, Houghton Go-onty, Michigan (T ext-fig. I 5 lo c . F) (Case and

Robinson, 1915; Templeton and Willman, I 963) because rocks exposed there

are said in the lite ra tu re to be of Black River age. However, conodonts

recovered prove to be Maysvillian (Middle Cincinnatian) in age.

More than 500 samples were collected and a l l were processed for

conodont-elements. Anticipating a low yield of elements 2 kgs. of

rock were processed from each sample and, where deemed necessary,

additional material was digested to increase the collection. The method of processing described by Collinson ( I 963) was followed. The

residue finer than I 6 mesh and coarser than 100 mesh was searched for conodonts. All samples were run through a Frantz Isodynamic separator and many were further concentrated by heavy-liquid techniques.

Specimens mounted on a glass slid e were photographed in incident

3 light through a Leitz Ortholux microscope at a magnification of lOOX with a Polaroid film holder and Polaroid type 57 black and white film .

The Polaroid film was trimmed and mounted on black cardboard, and continuous-tone 8x10 negatives were made at 50 percent reduction. The conodont-elements were not coated and none of the prints was retouched.

Conodont-elements from New York (T ext-fig, 1; Iocs, A, B) and

Coboconk, Ontario (T ext-fig. 1; Io cs. C, D ) are dark broin to black and opaque. Elements from the remaining samples are amber to lig h t brovTn and nearly transparent. Most of the fibrous elements are transparent to opaque and darker brown than the laminar forms.

Tables two, four, and five were prepared from direct counts of the'specimens collected and identified. Every element was collected from a l l samples even though the to ta l number of elements exceeded

2,000 in some samples. In this collection there are more than 26,000 id e n tifia b le elements, of which more than 5,000 are fibrous. Text-fig. 1. Index Map to Sample Localities, Localities 0, P, Q, are core holes . DESCRIPTION OF SMPLE LOCiJITISS

7OVA 1-9; Young, 19^3» Ross, 1964. Abandoned quarry, River S tree t

Lowille, New York, south side of Mill Creek, east of the rail­

road bridge; Pamelia and Gull River Formations, 42 feet sampled,

7OVB 1-27; Young 1943, Ross, 1964. /ilong Roaring Brook, East

Martinsburg, Lewis County, New York; Pamelia, Gull River, ¥ater-

totm, and Selby Formations, 143 fe e t sampled.

7070 1-6; L iberty, I 969, Okulitch, 1939. Roadcut along Ontario

Highway 35» 4 miles north of Coboconk, Ontario; Okulitch * s type

section of the Shadow Lake Formation and lower member of the Gull

River Formation; 30 feet sampled.

7OW 1-7; Liberty, I 969, O kulitch, 1939. Roadcut along Ontario

Highway 35» on the south edge of th e v illa g e of Coboconk,

O ntario. Type section of the middle and upper members of the

Gull River Formation; lower member of the Bobcaygeon Formation

sampled; 30 feet sampled.

7072 I - I 5» Liberty, 1954. Several readouts along Ontario High­ way 68 from the village of Birch Island to Little Current on

M anitoulin Islan d . New Highway 68 does not follow the old road, which is the route of Liberty’s Guidebook, thus it is useful

only p a rt of the route. 230 fe e t sampled. Samples 1-7, 0,5 m ile south of the v illa g e of Birch Isla n d , Svri.ft Current beds.

Samples 9-13» MacGregor quarry, S ifift Current and Cloche Island 6 beds. Samples 1^-15» Highway 68 bridge, north side of Goat Islan d ,

•unnamed beds above the Cloche Island beds,

7OVF 1-21, Case and Robinson, 1915» Templeton and Willman, I 963.

Abandoned quarry, southeast sidecf Limestone Mountain,

Sec. 24-, T, 51 N., R, 33 W,, Houghton County, Michigan. 137

feet sampled. The samples were highly productive of conodont-

elements, which proved to be Maysvillian in age,

7OVG 1-8, Hussey, 1952. River bluff on the northeast side of

the Escanaba River a t Bony F a lls power p la n t, Sec, 1, T, 4 l N .,

R. 2hW ., D elta County, Michigan. Bony F alls beds, 3^ fe e t sampled.

7OVH 1-lh, Agnew and Slo^^ 1955. Pikes Peak roadcut along Iowa

Higkfay 3^0, south of McGregor, NSi, Sec. 3^, T. 95 N ., R. 3 W.,

Clayton County, Iowa. Glenwood Shale, P la tte v ille and Decorah

Formations, 70 feet sampled,

7OVI 1-21, Templeton and Willman, I 963. Active stone quarry on

the rlississippi River bluff, 1.0 mile west of Batchtown, Illinois.

NEi, SEi Sec, 7, T, 12 3 ,, R. 2W-,, Calhoun County, I llin o is .

M ifflin , Grand Detour, Kachusa, Quimbys M ill Formations, 110

feet sampled,

7OVJ 1-34, Wilson, 1943, 1949, Type section of the Ridley Lime­

stone, exposures in the river bank on the south side of the East

Fork of Stones River near Ridley’s Mill on Jefferson Road and

along a secondary road uphill to the south from the river at Ridley's Mill, Rutherford County, Tennessee. Ridley and lower

Lebanon Limestones. 207 fe e t sampled.

7OVK 1-9, Wilson, 1943, 19^9. Coleman Cemetery. Murfreesboro

Limestone exposed in the bluff along the west bank of the East

Fork of Stones River, 1.0 mile west of W alterhill, Rutherford

County, Tennessee. 59 feet sampled.

7OVL 1-3, Wilson, 19'i3, 19^9. Pierce's Mill. Type section of

Pierce Limestone, north bank of the East Fork of Stones River at

Pierce's M ill, on Tennessee Highway 10, Rutherford County,

Tennessee. Murfreesboro, Pierce, and Ridley Limestones. 35

fe e t sampled.

70Vi'I I - I 9, Wilson, 19^3, 19^9. Sump and e a st face of the Vulcan

Materials co. quarry, Franklin Limestone Road, 2,0 miles west of

Una, Davidson County, Tennessee. Upper Lebanon, and lower Carters

Limestones. 95 feet sampled.

7OV 1-73, Wolcott, 1969. Samples 1-35, 40, 41. Roadcut along

U.S. Highway 27 from the north side of the Kentucky River bridge a t Camp Nelson to Scotts Grove Church, Jessamine County, Kentucky.

Type section of-the Camp Nelson Limestone, ISO feet sampled. Nosow and McFarlan, I 96O. Samples 35-39. Roadcut along Kentucky

Highway 39 on the southeast side of the Kentucky River fa u lt zone at Black Bridge on Hickman Creek, Jessamine County, Kentucky.

12 fe e t sampled, upper 6 fe e t of the Tyrone Limestone and the lower 6 feet of the Lexington Limestone. W olcott; 1969. Samples 42-73. Exposures along the creek on the

north side of Kentucky High'/ay 39» ^’est of Hickmar Creek and in

the roadcut along Sulphur Well Road south from the junction with

Highway 39 to the top of the h i l l . I 65 fe e t sampled. Upper

Camp Nelson, a l l of the Oregon, and most of the Tyrone Limestone.

7OZA 665-1210. Cominco American In c ., Core Ca-33, Sec. 15»

T, M» R. 63 N ., Mason County, Kentucky. 5^5 fe e t sampled.

Complete Middle Ordovician section from 20 fe e t above the

reported top of the Knox Doloimite through the Camp Nelson, Oregon,

Tyrone, and Lexington Limestones.

65X 3900-4000. Pan /imerican Petroleum Corp., Davidson ;?2»

Richland County, Ohio. 100 fe e t sampled, 4? fe e t of Knox

Dolomite and 53 fe e t oS^Sull River Limestone,

TlLk 973- 1175. Van D riest Core, SEt 33? 33?, Sac. 12, T. 13

N ., R. 22'J.f Sheboygan County, Wisconsin. 203 fs e t sampled.

P la tte v ille , Decorah, avd Galena Formations.

693-I 4. One sample from the Glenburnie Shale Member of the

V/aterto:-rn Limestone, Glenbv.’nie , Ontario. Donated by Professor

Stig M. Bergstrom, The Ohio S tate Université , PRSVIO-JS STUDIES OF THE BUCK RIVER GROUP

The type Black River Group of Hew York is a sequence of th in -

to massively bedded, argillaceous and dolomitic, sublithigraphic to

fine-grained, locally cherty, light to dark gray limestones. Rocks

later referred to the Black River Group were first studied by Eaton

(132’4-), who included them in the Metalliferous Limerook, "that

b e a u tifu l v ariety called Birdseye marble." Conrad ( I 636) described

the lower part of the Metalliferous Limerock as the Mohairk Limestone

(T ex t-fig . 2). The upper p a rt and the overlying "Grayiracke" were

named Trenton Limestone from e^qjosures a t Trenton F a lls, New York.

Black River Limestone was the name applied by Vanuxem (13^2) "to the

first range or cliff of limestone on Black River...composed of the

Birdseye of the Mohawk and the rock upon which the Trenton was placed.

The Black River limestone has at its base the primary rocks" and is younger than the C alciferous Group. "The Birdseye limestone is not

confined to New York. It is a rock in the geological sense. It forms

the surface of Nippehase Valley in Pennsylvania. It is the marble of

Frankfort, Kentucky...The same masses exist in the bluffs at Nashville,

Tennessee."

In 18'43, James H all referred to the "Black River Group" a l l the

rocks between the Calciferous Sandrock and the Trenton Limestone.

Later, however (Hall, 184?) he established a classification of the

New York Middle Ordovician section that survived into this century.

10 11

In that classification, Hall restricted the terra Black River Limestone to the upper beds of Vanuxera*s (1842) classification and recognized the Chazy, Birdseye, Black River, and Trenton Limestones.

The terra Mohawk, proposed by Conrad in I 836, was revived and re­ defined by Clarke and Schuchert (1399) to include the Loi-rville (used in place of Birdseye), Black River and Trenton Limestones, Cushing

(1903) introduced the name Pamelia for that portion of the original

Black River below the Lo^r/ille Limestone, Tt:o years later he placed th e Black River Limestone in the Chazy Group. The Chazy, according to the d e fin itio n of Grabau ( I 909) , contained th e Pamelia and Lovjville

Limestones above the Chazy Limestones of the Champlain V alley, "The

Chazy thus represents a tra n sg ressio n al se rie s. The Black River and

Trenton Limestones mark the continuance of the transgressional movement," Chazy was proposed as th e only Middle Ordovician se rie s and the Trenton Limestone was placed in the Upper Ordovician, Schuchert and B arrell (1914) proposed th e name Champlainian Series to encompass th e Chazy, Black River, and Trenton Groups and brought th e Trenton back to th e Middle Ordovician, Kay (1929) proposed the name Chaumont in a time-stratigraphie sense, for rocks "younger than Lowville and older than the Rockland," Wilson (1932) established that rocks of typical

Black River Limestone lithology overlie rocks of Chazy lithology in the Ottawa Valley and returned to Vanuxem’s classification of the Black

River,. By 1937» Kay was using the terras Pamelia, L o w ille , and

Chaumont as s ta d ia l designations although the former two had been used Eaton, 1824 Conrad Vanuxem Hall Cushing Kay, 1937 Kay, 1968 1839 1842 1843 Schuchert, ^1909 1910 1899

Graywacke

Cobourg Metaliferous Trenton Trenton Trenton Steuben Ls. Limerock Ls. Sherman Denley Ls. Fall Sugar River Ls. Kings Falla

Selby Fm.

Black Watertown Ls. Riv. Ls. Mohawk Birdseye Lowville Chazy Gull River Ls. LS. L b . Ls. Pamelia Fm.

Calciferous Sandrock ■ Text-fig. 2. Nomenclature of the Black River and Trenton Groups, New York, 1824-1968. 13 previously as lithologie terms.

Nomenclature of u n its of the Black River Group was stab iliz ed by Young (19^3). In a detailed lithologie analysis of rocks in the type region, west of the Adirondacks, he recognized the Pamelia,

Lowville, and Chaumont Formations, Recently however, Kay (1968) has pointed out that Lowville and Chaumont were originally time-stratigraphie concepts and should be regarded as stages. He divides the Black River

Group of New York in to Pamelia, Gull River, and Watertoi-m Formations

(or Limestones) and indicates that the Pamelia and Gull River belong in th e Lovrvillian Stage, whereas the yatertoim limestone is th e Chaumontian

Stage.' In O ntario, Kay regards the Shadow Lake and Gull River Forma­ tio n s as Lo'.rvillian and the Hoore H ill Member of the Gull River as

Chaumontian.

In 19% , Kay summarized the Middle Ordo^/ician as rocks younger than Beekmantovrn and older than Cincinnatian and divided the Middle

Ordovician in to two se rie s, Chazyan and Mohawkian. Recognizing unconform ities a t th e base and top of the Black River Group in New

York, Kay had proposed, in 19^7» a new series for the lower part of th e Mohawkian based upon the Middle Ordovician section in the Appala­ chians of Virginia. "The Eolarian Series comprises rocks younger than

Lincolnshire, about late Chazyan, and older than Nealmont, early

Trentonian, and time equivalents." It was obvious that by that time the names Chazy, Black River, and Trenton were being used in two d if ­ ferent and conflicting senses, both lithologie and chronologic. 14

Twenhofel and others (1954), in their Ordovician Correlation Chart for

North America, recognized two stages in the Champlainian Series, the

Chazyan and Kohawkian, with the Mohawkian subdivided in to the Black

River aïid Trentonian,

In a c la ssic monograph. Cooper (195^) proposed fiv e stages between the Canadian Series and the Trentonian Stage of the Champlainian

Series, based upon a study of brachiopods from the Appalachians and elsewhere. The Trentonian Stage iji Cooper’s report however includes only the upper part of the type Trenton Group of New York. The entire

Black River Group, together with the Rockland and Hull "Formations"

(Selby, Kapanee, and Kings Falls limestones of Kay, 1968), the lower p a rt of the Trenton Group, were placed in the W ilderness Stage belo:-: the Trentonian. Thus the term Black River seems to have been used by Cooper only in a lithologie sense as originally proposed by Vanu:cem

(1842). The Wilderness Stage is then a time-stratigraphio unit that includes the Black River Group and the lower units of the Trenton

Group, the Selby, Napanee, and Kings F alls Limestones of Kay (1963),

According to Cooper (1956), the Wilderness faiuia is especially character­ ized by abundance of the brr.chiopods Oeoikina. Strouhonena. Pionodema. and Doleroides and is succeeded by the Trentonian with its flood of cry p to lith id tr ilo b ite s . However, only Doleroides and one other brachiopod genus (Teratelasma) are shoT-m to be confined to the Wilderness

Stage and cryptolithid trilobites range through the Trentonian into rocks of Cincinnatian age. Bergstrom (1971) has shown that some of Cooper's brachiopod-basod correlations are in need of revision with 15

respect to conodont-based correlations, Im.on% these the celebrated

Christiana brachiopod fauna is sho:-m by Bergstrom (1971) to be time-

transgressive from south to north and northwest in the Appalachians,

Because of a marked provincialism , there is a t present no conodont

correlation between Ordovician rocks exposed in the Appalachians and those of the Black River Valley, However, Bergstrom has demon­

strated that Cooper’s stages overlap in part in the Appalachians,

Flower (1957) agreed m th Cooper (195^) in including the

Rockland "Formation" of the Trenton Group with formations of the Black

Ri»- r Group in the same stage. But he preferred to employ the traditional stadial designation. Black River, to this expanded unit, rather than adopt Cooper's Wilderness Stage for these rocks. If the Rockland is placed in the Black River, a conspicuous change in cephalopods would coincide vdth the Black River-Trenton Boundary.

Kay ( i 960) recognized Chazyan, Blackriveran and Trentonian as series of the î-îiddle Ordovician, In his view, the Blackriveran is composed of three stages, the Pamelian, Lovrvillian, and Chaumontian, which indicated Kay's belief that these units are distinct and essen­ tially isochronous, .

Since the name Trenton had acquired a time connotation, which did not even encompass a l l of the Trenton Group, in addition to i t s long­ standing lithologie use, Fisher (1962) proposed that a Barneveld

Stage be recognized, to include rocks of the Trenton Group between the base of the Shoreham "Formation" and the top of the Cobourg

"Formation," Sweet and Bergstrom (1971) demonstrated th a t the base of 16 the Cobourg "Formation” in the type sections of the Barneveld (Trenton

Falls, New York) is at the same biostratigraphic level as the base of the Bdenian Stage in the Cincinnati Region (Ohio, Kentucky, Indiana).

Hence Barneveld overlaps Shorehamian and Bdenian and there seems no reason to retain it, Schopf (1966)^ however, in his detailed analysis of the Trenton Group conodonts, used Wilderness and Barneveld as stage names for the intervals during which the classical Black River and Trenton Groups were deposited.

P rio r to I 96O, it was commonly considered that each of the Black

River Group lim estones was a separate isochronous u n it and th a t no la te r a l facies relatio n sh ip existed between them (Young, 19^3j Kay,

19'+3, i 960). This concept was perhaps carried to an extreme by

Templeton and Willman, whose paper, although published in I 963» was essentially complete in 1953» at the time of the death of Templeton,

They indicated that conditions of sedimentation were remarkably uniform during the Champlainian over much of the stable interior of the conti­ nent, In their view, lithic units parallel bentonites and are thus time-stratigraphie units. Variations in clay content that distinguish units are constant throughout the Champlainian of the Midcontinent. They then correlated units around the-eastern Midcontinent on the basis of very small lithologie variations and stated that "within the Mis­ sissippi Valley the position of stage boundaries are traced more effectively by lithologies than by faunal criteria.” In the opinion of

Templeton and Willman, the conclusions drax-m by Winder (I960) on the facies relationships in the Black River and Trenton Groups of New

York, O ntario, and Quebec do not apply to the M idcontinent. 17

Since the publications of '.finder's (I960) paper many authors

(Fisher, l9o2; Hofaan, 1963; Dineley and Barnes, 196^-; Barnes, 196?;

Mukherji, 1969) have drawn conclusions similar to his about relations between rocks of the Black River and Trenton Groups, at least in New

York and Ontario, Winder interpreted these rocks as a transgressive

sequence in which the red clastic unit (Shadow Lake) at the base of the section is a transgressive shoreline deposit. Fine-grained limestones of the Gull River and Moore H ill Formations are quiet water lagoonal deposits, and b io c la stic lim estone (Coboccnk) represents the higher energy surf-zone environment, Fisher (1962) drew the same conclusions as to the lateral facies equivalence of the Pamelia,

L o w ille , and Chaumont "Formations" of New York, Hof man (1963) described the transgressive nature of the Pamelia Formation of the

Ottaqua Valley, Dineley and Barnes (1964) and Barnes (196?) came to the same conclusions concerning the facies relationship between the

Loifville, Chaumont and Rockland Limestones of O ntario, Mukherji ( I 969), in a pétrographie study of the Black River Group of southwestern

Ontario, described the Shadow Lake and Gull River Formations as lateral equivalents across a supratidal mudflat.

There seems to be strong evidence that lithologies typical of the c la ssic Black River and Trenton Groups are a t le a s t in p a rt facies related in New York and O ntario, and i t seems lik e ly th a t th is relationship exists throughout the eastern Î-Iidcontinent. Templeton and Willman ( I 963) unfort’inately, did not have the benefit of detailed 18 paléontologie evaluation of all the units that they correlated. For

example, from the present study, it can be showi that their correlation

of the Glenwood, P la tte v ille , Decorah, and Galena Formations from Pikes

Peak, Iowa, to southeastern Minnesota is not substantiated by the dis­

trib u tio n of conodonts. That i s . Fauna 7 (Sweet and others, 1971) is

represented in the Glenwood and Platteville of Iowa, but only in the

Glenwood of Minnesota (Webers, 1966). Fauna 8 elements are present in

the Decorah and lower Galena of Iowa (Sthington, 1959) but dominate the

fauna of Minnesota from the Carimona Member of the P la tte v ille to the lowest part of the Galena Formation, Fauna 9 appears in the upper part

of the Galena Formation of Iowa but lower in the Galena of Minnesota,

Thus th is sequence is transgressive from Iowa to Minnesota,

In conclusion, i t seems b est to use the name Black River Group

in its original sense, that is as the name for a lithologie rather than

for a tirae-stratigraphic entity, Stadial or serial designations such

as Wilderness (Cooper, 1956) or Bolarian (Kay, 19^7) have been proposed

for time-stratigraphie units that include the Black River Group,

However, n e ith e r Wilderness nor Bolarian seems to be adequately defined

in paléontologie terms. Obviously detailed regional studies of long

stratigraphically complete sections will be required to define stadial u n its of the Champlainian Series adequately, Conodont-elements, even

though they show marked provincialism , seem to be independent of lo c al

facies variations (Walliser, 19oh). Thus at the present they offer

the best means of demonstrating regional correlation. Studies by 19

Sweet and others (1971) and BergstrSm (1971) point toward a revision of stadial subdivision but they also indicate that the problem has not yet been solved. C0H0D0NT3 OF THE BLACK RIVER GROUP 1\1B EQUIVALEirr STRATA

The first conodont-element described from rocks now included in

the Black River was probably Prioniodus radicans (Hinde, 1879).

Dineley and Barnes (196^) listed common form-genera such as Polvcaulodus.

Ptiloconus, Belodina, Cordylodus. Oistodus, and Panderodus in their

environmental interpretation of the Ottawa Limestone and Schopf (1966)

described elements of an "early Wilderness fauna" collected from the

Black River Group of the type region and from i t s la te r a l equivalents

in the Ontario lowlands.

As can be seen from the few previous reports just listed, fibrous

genera dominate the Black River fauna and the laminar form-genera

identified include Belodina. Panderodus, Phragmodus, Dicognathus,

Oistodus. Trichonodella. Ozarkodina. and Cordylodus.

Phraamodus undatus. a key species of Fauna 8 (Sweet and others,

,1971) is represented in Schopf*s collection only in the uppermost

Xvatertoxm ("Chaumont") Formation, thus a l l of the Black River Group

below this level is probably equivalent to strata containing Sweet

and others * (1971) Fauna ?. Phraamodus inflexus, a key species to

Fauna 7, is present in the Pamelia Formation of New York (Sweet and

others, 1971).

Schopf recognized early and late faunas in the Wilderness Stage,

The la te Wilderness fauna, characterized by Phragmodus undatus « Belodina

compressa, and the earliest appearance of elements with European

a f f in itie s , represents Svieet and others* Fauna B; Schopf*s early

20 21

W ilderness faxma i s Sweet and others* Fauna 7.

Bames (I 967) listed conodonts identified in samples from selected Chauriontian localities. His list includes elements that are here included in the multielement species Belodina compressa, Plectodina aculeata, Drepanoistodus suberectus, Panderodus gracilis, P. panderi,

Curtognathus robustus, Ç. t.vpus, and Srismodus radicans. This assembly i s c h a ra c te ristic of Faunas 7 and 8, However, because phragmodiform elements are not reported, it is not possible to define the fauna further. This is also true of the Black River Group collections of

Schopf ( 1966) and those described here, Bames (I 967) l i s t s the form- species Oulodus c a ste r! Pulse and Sweet, which is a component of multielement Oulodus Oregon!a (Branson, Mehl, and Branson) (BergstrSra and Sifeet, I 966). This occurrence, if verified represents the lowest stratigraphie level at which this species of Oulodus has been identified.

Bames' listing of Oulodus caster! (0. oregonia) in Black River strata in Ontario is puzzling because no oulodiform elements are contained in either the extensive Trenton Group collections of Schopf or in the Black

River Group collections described in this study.

Identifiable conodont-elements assembled in this study represent

19 genera and 2k species. Many current workers approach conodont taxonomy from the m ultielem ent p oint of view (Lindstrom, 19^4; W alliser,

196h-; Linds trom and Z iegler, 19o5j Bergstrom and Sweet, I 966; Webers,

1966; Kohut and Sweet, 19o3; Jeppson, 19^9; Sweet, 1970). Sweet and

Bergstrom (1970) present a h isto ry of conodont taxonomy and describe 22 both the form and multielem ent approaches. The multielem ent taxonomic approach is used here because the author believes it to be the most

realistic taxonomic procedure. Although the form-element approach was used by Pander (1356), this precedent is not binding on conodont workers. There is no a priori reason for accepting this concept. The

similarity of stratigraphie occurrence of elements, color, size, mode of denticulation and association in samples is strong eveidence in favor of multielement taxonomy. I t represents the relatio n sh ip s sug­ gested by statistical studies (Kohut, I 969) of the elements more closely than does form-taxonomy. Thus this author chooses to follow th e m ultielem ent approach to conodont taxonomy.

Fibrous Conodont-elements

In 1933» Branson and Mehl recognized and named a major group of conodont-elements from the Harding Sandstone of Colorado, They described this group as follows:

?In the first place these Harding conodonts constitute a very primitive group. The entire assemblage, with very few exceptions, represents a division very distinct from the great majority of conodonts although duplicating many of the latter in general form. This difference can at present be describe:'; best as "fibrous" structure rather than the apparently laminar arrangement of the substance in the ordinary type. The simple cones of the Harding split lengthwise rather than across as is the case among most of the distacodids. The gro’np typical of the Harding is u su ally recognizable through the d u ll surface and amber color, although some specimens have shiny surfaces, Perhaps the most characteristic feature of the primitive group is the fact that the basal surface is attached directly to the surface of the jaw support almost by ankylosis so that the great majority of the specimens re ta in fused to them a p art of the jaw. They seem to lack entirely the basal excavation designated by Pander as the *pulp’ cavity that is particularly evident among . the ordinary distacodids," 23

Later (19-^) Branson and Mehl considered the difference between fibrous and laminar conodont-elements to be of sufficient significance to recognize the fibrous elements under a new suborder, the Kourodontiformes,

Rhodes and Wingard (1957) concluded from x-ray studies of fibrous elements that these elements are indeed fibrous. That is, the crystallites have a preferred orientation parallel to the long a:d.s of the cone. The fibrous nature of some conodont elements was viewed by Hass (1962) as being of no significance and the "original lamellar structure has been obscured through alteration." Lindstrom (1964) agreed with Hass (1962) that fibrous elements are indeed lamellar.

Lindstrom concluded however th a t fibrous elements do d iffe r from lamellar elements, and he said "'/fell preserved conodonts of the

•fibrous* type are also characterized by the absence of white matter, or i t s r e s tric tio n to the groirth axis of the cusp." However, he f e l t that the suborder Neurodontiformes should not remain a suborder as it now includes elements which are altogether normal in structure. On the basis of thin-section studies, Schwab (l9o5) agreed with Hass (1962) and Lindstrom (1964) that fibrous elements are actually laminar.

Bames, Sass, and Monroe (1970) studied the internal structure of conodont elements Trrilth transmission and scanning electron-microscopes.

The definition of the crystallites varies in the species studied. In

Dreoanodus homocurvatus the crystallites are poorly defined, long, linear, and parallel to the inter-lamellar spaces; while in Polvcaulodus bidentatus. they are well-defined, prismatic in shape, and parallel to Zk the inter-lamellar spaces. In Ptiloconus gracilis, the crystallites

are flat, flaky structures and randomly oriented. The character of the lamellae is similar >dthin each form-species studied by them. In

the form-genus Drepanodus the lamellae are variable in thickness, while they are uniform in form-species Polvcaulodus bidentatus.

Muller and Kogami (1971) agreed ifith Hass* (1962) conclusion th a t

the differentiation between the suborders of conodonts does not exist.

The grovrth lam ellae are observed to be the same in both groups, although variable in thickness. In the fibrous forms the white matter is not well developed but this is of écologie, not taxono-nic, significance.

Lindstrom (1971) suggested that the term fibrous be dropped from

conodont-element taxonomy as the so-called fibrous elements have a lamellar structure. A distinguishing feature lies in the hyaline

aspect of the element and Lindstrom states that "The hyaline conodonts appear in the main to be a group of high-ranking taxonomic distinction."

These forms vd.ll be described in this report as fibrous conodont-

elements.

Laminar Conodont-elements

The Black River Conodont fauna is dominated by Drepanoistodus

suberectus. Panderodus g ra c ilis , and Plectodina acu leata. Very l i t t l e provincialism is demonstrated by this fauna within the area studied, probably because of the similarity of conditions that prevailed in much of eastern North America during the period of time vzhen these rocks were deposited. That is. Black River rocks and their lateral

equivalents represent the sediments deposited during a major transgression 25

of the North American continent. Only two species in th is Black River

conodont fauna show any restriction to the margin of the Appalachian

Basin, Apoalachignathus delicatulus and Belodella niger. A. delicatulus

is present in th e Pan American Davidsnn core, Richland County, Ohio,

with elements of Phragmodus to rtu s , a key species to Fauna 6 of Sweet

and others (1971). A. delicatulus ranges up into Fauna 7 where it

overlaps the lower portion of the range of Phragmodus inflexus in the

Camp Nelson limestone in Kentucky and in the Pierce and lower Ridley

Limestones of Tennessee,

Belodella niger has only one recorded appearance in this

.collection, in the Pierce and lower Ridley limestones of the Central

Basin, Tennessee, Elements of this species are reported from the

Copenhagen Formation of Nevada (Ethington and Schumacher, 19^9) and

the Camic Alps of Italy (Serpagli, I 967),

Oulodus serratu s and Polyplacognathus ramosus are re stric te d

to the western sections sampled in th is stu d y ,. P, ramosus ranges from

the Mifflin Formation at the base of the section in BatchtoTrci Quarry,

Illinois (Text-fig,l, loc. I), into the Quimbys Mill Formation at

the top of the section. It ranges from the lowest sample of the

Platteville Formation at Pikes Peak, Iowa (Text-fig, 1, loc, H)

into the Decorah Formation at the top of the section sampled. It is

present in-samples from the Platteville and Decorah Formations in the

Van D riest Core, Sheboygan County, Wisconsin (T ext-fig, 1, lo c , Q),

P, ramosus has also been reported from the Glenwood, P la tte v ille , and

upper Decorah Formations of Minnesota (Stauffer, 1935a; Webers, 1966), 26

Except for appearances in the upper Lebanon Limestone of Tennessee, the species is not knovm from Black River rocks east of the above mentioned sections. Thus P. ramosus apparently migrated eastward from the Mississippi River Valley during Rocklandian for it is knoT-m

from the Unnamed beds of Cloche Island (this report), the Lexington

Limestone of Kentucky and Ohio (Bergstrom and Sweet, 1956), and th e

Trenton Group of New York and Ontario (Schopf, I 966).

Elements of Oulodus serratus are abundant in the Decorah Formation at Pikes Peak, Iowa (Text-fig, 1, loc. H). Elements of the species are also present in one sample from the Decorah Formation in the Van

D riest Core, Sheboygan County, Wisconsin and in the highest sample in

Batchtown Quarry, Illinois (Text-fig. 1, loc. I), near the top of the

Quimbys Î-Ü11 Formation, Other than these four species, the Black

River fauna described in this study maintains a uniform character regionally.

The almost mutually exclusive stratigraphie distribution of

Scandoius suoerbus and Belodina compressa is most informative (Text- fig . 3). The oldest specimens of B. compressa in the irriteras collections are from the Murfreesboro Limestone, Central Basin,

Tennessee at a level well below the highest occurrence of Phra?modus in flex u s. The sampled Murfreesboro section is also closer to th e

Appalachian Basin than are any of the other sections from which conodonts were collected in this study. In Kentucky, B. compressa appears first at the level at which P. inflexus disappears. In New York, where P. inflexus has been reported from the Pazielia (Sweet and others, 1971)» 27

B, compressa appears in the upper Pamelia, At Coboccnk, Ontario

(Text-fig, 1, loc, C, D) B, compressa is represented in the upper

Gull River Formation, On Grand Cloche Island, Ontario, elements of B, compressa occur in the basal Swift Current beds, Seddon and Street

(1971) suggested th a t Belodina and Panderodus were both members of a shallow water fauna, but that Belodina was the deeper-water representative of the two. In each, Panderodus gracilis appears lower in the section than Belodina compressa. As these sediments represent a transgressive sequence, it would appear that B, compressa is the deeper-water representative of the two,

Scandodus superbus might have had environmental requirements similar to those of Belodina compressa (Text-fig, 3)» That is, in the

Central Basin of Tennessee, its highest occurrence is well below the highest P, inflexus, whereas in Kentucky its highest occurrence is much closer to the level at lAich P, inflexus disappears, S_, superbus is also present in V'e lower Pamelia in New York, where P, inflexus has been reported (Sweet and o th e rs, 1971); and on Grand Cloche Islan d ,

Ontario (Text-fig, 1, loc, E), it ranges above the first appearance of

P, undatus. These occurrences suggest that S, superbus was restricted to shallower water than was Belodina compressa.

The "Zone” o f Phragmodus inflexus

The reported d istrib u tio n of four species of Phragmodus suggests to the author a preliminary zonation of Black River rocks and their la te r a l equivalents in the eastern K idcontinent, Phragmodus to rtu s ranges almost to the top of Chazy s tra ta in Quebec and P, inflexus is CENTRAL CAMP COMINCO ROARING BASIN NELSON CORE BROOK TENNESSEE KENTUCKY KENTUCKY NEW YORK DATUM Lowest occurrence of Phragmodus undatus

100 f t .

— Highest Phragmodus inflexus — — Lowest Belodina compressa Highest Scandodus superbus

T ex t-fig . 3. Comparison of occurrence of Belodina compressa and

Scandodus superbus. 29 knovm from the Pamelia of New York (Street and oth ers, 1971). Hence these two species appear to succeed one another stratigraphicaHy in the region that includes the type area of the Black River Group. The only knoim occurrence of P, to rtu s and P. inflexus in the same s t r a t i ­ graphie section, however, is in the Pan American Davidson Core,

Richland County, Ohio, described in this report. In that core, P. tortus is represented in samples at one-foot intervals from 3935 to

3917 feet and P. infle'cus is represented in samples immediately above.

Since the Chazy Group is unconformably overlain in the Champlain Valley,

New York, by rocks that may be equivalent to the Black River Group, the highest occurrence of P. to rtu s in the Chazy Group may not be the upper limit of the range of the species. Thus Gull River samples from the subsurface of Richland County, Ohio, that contain elements of P. to rtu s may be from s tra ta younger than any in the ty p ical Chazy, The le v el a t which P. inflexus appears immediately above P. to rtu s is sug­ gested as the lower lim it of th is inform al zone. The word zone is se t o ff by quotation marks to in d icate th a t i t is an inform al zone, and the zone will be used here in place of the phrase "strata dominated by Fauna 7 of Sweet and others (1971)." The boundary ju s t described coincides with the change between Faunas 6 and 7 described by Sifeet and others (1971).

Phragmodus inflexus is immediately succeeded by P. cognitus in only one reported location, southeastern Minnesota (Webers, I 966).

In every section studied for this report, there is a stratigraphie 30

interval between P. inflexus and P, cognitus that has not yet yielded

any phragmodiform elements. P. undatus. a widespread and well-knoT-m

Middle and Upper Ordovician multielement species (Bergstrom and S%;eet,

1966) appears above the f i r s t occurrence of P. cognitus. and the ranges

of th e two species overlap (Webers, I 966),

The top of the "zone" is distinguished by the first appearance

of Phragmodusundatus. The overlapping ranges of Phragmodus undatus

and Plectodina aculeata define Fauna 3 of Sweet and others (1971).

Plectodina aculeata. common in the Phragmodus inflexus "zone",

has been found in this study to range lower in the section than was

suggested by Sweet and others (1971). It is represented beloif the level

of the f i r s t occurrence of Phragmodus inflexus in every stratig rap h ie

section from which P. infle:x.s is reported.

The sequence of sections exposed a t P ierc e’s M ill, Coleman

Cemetery, and Ridley’s Mill, along the East Fork of Stone River,

Rutherford County, Tennessee, and the section exposed in the Vulcan

Materials Co. quarry at Una, Tennessee are tentatively proposed as

reference sections for the Phragmodus inflexus "zone". The base of

the "zone" is placed at the base of the Pierce Limestone, which pro­ duced the oldest representatives of P. inflexus in this collection.

The highest recorded occurrence of P. inflexus is 35 feet below the

top of the Lebanon Limestone in the Vulcan quarry. Elements of P. undatus are kno%m from the base of the Hermitage formation in the same

section (undescribed collections. Dr. Walter C. Sweet). The age of the "zone" is middle Middle Ordovician, This "zone" cannot be easily 31 correlated vxith Bergstrom’s zonation (1971) for the Balto-Scandic faunas of the Appalachians, Bergstrom suggests that the Black River

Group of New York may correspond to some p a rt of the lower /cioruho?- nathus tvaerensis Zone. If this is a correct assessment, then the

Phragmodus inflexus "zone", which embraces most of the type Black

River Group, is equivalent to some p a rt of the lovrer Amoruhognathus tvaerensis Zone,

The Phragmodus inflexus "zone" includes th e P ierce, Ridley,

Lebanon, and Carters Limestones of the Central Basin of Tennessee,

At Camp Nelson, Kentucky, the base of the "zone" is apparently 162 feet below the top of the Camp Nelson Limestone, Elsewhere in Kentucky, the base of the "zone" may be lower in the lithic section, for elements of P, inflexus have been collected from the Camp Nelson in the Cominco Core, Mason County, Kentucky, only ?0 feet above the top of the Knox Dolomite, At Camp Nelson, Kentucky, the top of this

"zone" is 6 feet below the top of the Tyrone Limestone; however, in the Cominco Core, P, undatus is not represented in the Tyrone and does not appear until a level 18 feet above the base of the Lexington

Limestone, The base of the "zone" can be placed at 391? feet in the

Pan American Davidson core, Richland County, Ohio, in the Gull River

Formation, 36 feet above the Knox Dolomite, The top of the "zone" is not recognized in this core because the core is only 100 feet long. The

"zone" probably includes almost the entire type Black River Group in

New York a t Roaring Brook (T ext-fig, 1, lo c. A), Phragmodus inflexus 32 is present in bhe Pamelia (Sweet and others, 1971)• £• undatus first appears in samples from the basal Selby Formation at Roaring Brook.

Schopf ( 1966), too, recorded P. undatus from the basal Selby at Roaring

Brook, but he also recovered elements of P. undatus from the uppermost

WatertoTm a t Dexter Quarry, New York, and Rockland Quarry, O ntario,

Hov/ever, Bames ( I 967) has shown that the Watertovjn-Selby contact is probably a level of facies change.

No phragmodiform elements were recovered from the GuH River-

Bobcaygeon section a t Coboconk, O ntario, (T ext-fig, 1 , lo c , C, D) sampled for this study, Schopf (I 966), however, reports elements of P. undatus from th e middle member of the Bobcaygeon Formation,

The top of th e Phragmodus inflexus "zone" is thui te n ta tiv e ly drawn a t the top of the lower Member of the Bobcaygeon Formation, On Grand

Cloche Island, the top of the "zone" is 5 feet above the base of the

Cloche Island Beds, for this is the loifest occurrence of P, undatus in th a t sectio n . The beds e:

6 and 7, The top of the "zone" is 7 feet above the base of the Decorah

Formation in th e Van D riest Core, Sheboygan County, W isconsin, At

Pikes Peak, Iowa, the top of the "zone" is in the Guttenberg Member of the Decorah Formation, 5 feet above the top of the Platteville, At

Batchtoim Quarry, Illinois, neither the base nor the top of the "zone" can be defined. CORREUiTIOH OP TH3 SECTIONS STÜÛIED

T e x t-fig , 28 svraraarizes the author’s co rrelatio n s of sections considered in th is study. Phra?rnodus undatus, whose appearance marks th e upper boundary of th e Phragmodus infle:cus "zone" as proposed here, i s represented in almost every section sampled or specimens of the species are reported to occur at a kno^-m stratigraphie level above the highest samples collected for this study. These correlative points are located near the top of the correlation chart.

Elements of Phraimodus inflezcis are present in only six of the sections sampled. This species i s the key to the Phragmodus inflexus

"zone". In four of the sections studied, the upper stratigraphie lim it of P. infloois can be established. The highest occurrence of P. inflexus in Tennessee is 35 fe e t below th e top of th e Lebanon Limestone, The interval between the highest P. inflexus and the lowest P. undatus is

112 feet thick in the Central Basin of Tennessee. The highest occurrence of P. inflexus in the Camp Nelson Limestone is 181 feet above the base of the exposed section or 63 feet below the top of the Camp Nelson.

Thus an interval of 172 feet exists between the first appearance of P. undatus and the last occurrence of P. inflexus. In the Cominco Core, the highest occurrence of elements of P. inflexus is at a depth of

895 feet in the core, 88 feet below the top of the Camp Nelson Limestone and 230 feet below the lowest occurrence of P. undatus. P. inflexus i s represented in a sample 9 fe e t above the base of the Quimbys M ill

33 y*

Formation in the section at Batchto'.m Quarry, Illinois, just 14- feet below uhe low est occurrence of Oulodus se rra tu s. Webers ( I 966) found elements that are assigned to 0. serratus in this report associated :d.th

Phragmodus cognitus in the lowest sample from the P la tte v ille Formation of southeastern Minnesota, In this study elements of 0 . serratu s have been found with P. cognitus in the upper foot of the Platteville

Formation at Pikes Peak, Iowa, In samples from the Van Driest Core of

Wisconsin, dements of 0 , serratus are present in one sample, which also contains the lowest stratigraphie occurrence of P, undatus at that location. Thus it appears that 0, serratus is present in the uppermost portion of the Phragmodus inflexus "zone", but ranges above the upper boundary of this "zone." The appearance of elements of 0 , serratus in the highest sample collected from the Quimbys 1-Iill Formation a t

Batchtovm Quarry, Illinois, represents the uppermost portion of the

Phragmodus inflexus "zone," Samples from the in terv al between the highest P, inflercus and the lower P, cognitus or P, undatus in each of these sections were large, ranging from 1- to 4-kgs, and the author suggests th a t the absence of phragmo;diform elements in them is not the re s u lt of sar.ipling error or small sample size. On the contrary, the absence of these elements suggests environmental control, perhaps a response to water depth.

That i s , Seddon and Sweet (1971) have suggested th a t conodonts occupied a habitat similar to chaetognaths viith different species segregated by vertical stratification. In their Ordovician example. 35

Phragmolus is suggested to have been restricted to deeper levels in the photic zone. Thus these elements would be absent in rocks th a t accumulated in relatively shallow water. Because there appears to be an unconformity between the Carters and Hermitage Formations in the

Central Basin of Tennessee (Wilson, 1948, 1949), and between the Tyrone and Lexington Limestones of Kentucky (Bergstrom and Sweet, 1966;

W olcott, 1969) , the absence of Phragmodus in the upper Lebanon and

Carters Limestones of Tennessee and the upper Camp Kelson, Oregon, and lower Tyrone Limestones of Kentucky may be the result of a shallow- of th e water p rio r to the time of Tyrone Limestone accumulation. Thus in the Eastern I-îidcontinent there is apparently an interval between those samples T-rith representatives of P. inflexus and those :rith P. cognitus or Pj_ undatus vathin which it is not now possible to locate th e upper lim it of the range of Phragmodus in flex u s.

Annalachignathus delicatulus is represented in four sections, and the distribution of specimens indicates that the upper range lim it of the species is in beds in the "zone"cf Phragmodus in flex u s. In the

Central Basin of Tennessee, A. delicatulus ranges 1? feet above the base of the Ridley Limestone, 42 feet above the lowest P. inflexus.

In undesoribed collections of Dr. Walter C. Sweet at The Ohio State

University, A. delicatulus ranges to :d.thin 40 feet of the top tif the

Ridley, 125 feet below the highest P. inflexus. In the Carç Nelson

Limestone outcrop cJf Kentucky, A. delicatulus ranges to in.thin 80 feet of the highest P. inflexus and in the Cominco Core, Mason County,

Kentucky, .to within 105 feet of the upper range limf.t of that key 36 species. Thus it appears that the top of the range of A. delicatulus is near the middle of the range of P. inflexus. The base of the range of A, delicatulus cannot be determined from this study, but the species is represented in samples T-âth Phragmodus tortus from the Pan American Core, Richland County, Ohio, above the Knox Dolomite, CHAI'îPL/ùmN CORRSIATIONS BY OTtiSR FOSSIL GROUPS

Graptolites are used for zonation of the Ordovician sequence in

B rita in , France, A ustria, Scandinavia, A u stralia, and North America

(Berry, 19^0); and Bergstrom (1971) has been able to correlate Balto-

Scandic conodont faunas to the graptolite sequence quite closely.

However i t is not p ossible with our- present knowledge of conodont

distribution to correlate the Balto-Scandic conodont faunas with

Midcontinent conodont faunas of North America because those faunas

are markedly different from the one described here or from other

Midcontinent faunas described elsewhere (Sweet and others, 1971),

The g ra p to lite sequences and composition are the same in th e Yukon,

Great Basin, Texas, Oklahoma, New York, and Newfoundland (Berry, 1964); however they are applicable only to the thick argillaceous facies of

the Ordovician, Berry (I960) equates the graptolite faunas and zones to Cooper’s (1956) brachiopod stages but without specific statement of the common occurrence of the two, ”The 'Nemagraptus gracilis' zone occurs in rocks correlative with the lower part of the Porterfield

stage” (Berry, I960), Kay (I960) stated the commonly accspted conclusion that the graptolites from the argillaceous sequences have not been

clearly related to the carbonate sequence faunas, Bergstrom (1971) has in p a rt overcome th is problem vrith h is zonation by conodonts, based upon the common occurrence of graptolites and conodont-elements 37 38 in Sweden. In western Utah, Rigby (1953) has studied a Lower and Middle

Ordovician section that contains both abundant graptolites and trilobites and has been able to correlate Hintze's trilobite zones (1951) ^-rith the graptolite sequence, IVhittington (1959) states that the trilobite co llectio n s suggest co rrelatio n s sim ilar to those advanced by Cooper

(1956) on the b asis of brachiopods, and reports th a t there is a marked change in trilobite faunas similar to that in the brachiqiod fauna at the top of Cooper’s W ilderness Stage, Del-iott (1964) reports a faunal break based upon trilobites near the Black River-Trenton Group contact that is correlative i-rith one at the Platteville-Decorah contact in

Wisconsin and Minnesota, Ross (1954) suggested a cliange of the bryozoan fauna a t th is le v el in New York, Thus th e re is evidence of a change in several different groups near the hlildemess-Bameveld boundary that supports the contention of Cooper in establishing the Wilderness Stage,

Kay ( i 960) however indicated the d iffic u lty of correlating Cooper’s stages from the Appalachians to New York since the Black River Group as a whole is only poorly knovm paleontologically. Flower (1957) indicated th a t he would put the Selby in to th e Black River Group fo r paléontologie, not lith o lo g ie , reasons; and th is change would put the Black River-Trenton boundary at a change in the meager cephalopod fauna,

Ordovician correlations based upon graptolites appear to be quite good -rithin argillaceous rocks whereever they are present,

Trilobites appear to correlate reasonably well :fith the graptolites 39 but they have not been studied in detail from the Blade River Group of Nevr York. The cephalopods are not well knovm from the Black River

Group of New York, The brachiopods and bryozoans are probably controlled by bottom conditions and some of Cooper's (195Ô) co rrelatio n s based upon brachiopods have been sho/in by Bergstrom (1971) to be u n reliab le,

BergstrSm suggests that the Black River Group (lower Wilderness) probably belongs in h is Amoruhoenathus tvaerencds Zone, and sta te s th a t

"it is evident that the type sequence of the Porterfield Stage corres­ ponds to a stratig rap h ie in terv al from the upper sub?one of the Pygodus

anserinus Zone tc an apparently rath er high le v e l in the Amorohognathus

tvaerensis Zone," This correlation indicates a rather extensive over­ lap of the Wilderness by the Porterfield Stage,

Conodonts seem to offer the best possibility of correlation, particularly in the carbonate facies, however we have not yet been able to corrolate closely the Champlainian faunas of the Appalachians

(Balto-Scandic, Bergstrom, 1971) with those of the îüdcontinent. CORRELATION I'ETH OTHER AMERICM SECTIONS

The sections sampled a t Roaring Brook and L o w ille , New York, and Coboconk, O ntario, d ire c tly underlie the Trenton Group rocks studied by Schopf (I 966) , Indeed Schopf’s collectio n s and th e ones described here overlap since he collected a few samples from the

Black River Group a t Roaring Brook and Lo:- 7v il le , New York; and a t

Roaring Brook, the highest sample here described is from the basal

Selby Formation. At Coboconk, O ntario, th e w rite r sampled in to th e lower member of th e Bobcaygeon Formation. Thus these samples provide a continuous section vrith the material collected by Schopf,

The section sampled a t Camp Nelson, Kentucky, includes the Camp

Nelson, Oregon and Tyrone Formations, which immediately underlie the Lexington Limestone. Because the lower 6 feet of the Lexington were also sampled, this set of samples forms a continuous sequence with the co llectio n s of Bergstrom and Sweet (I 966). The highly productive suite of samples collected at Pikes Peak, Iowa, is from rocks that are overlain by the Galena Formation, Although Ethington

(1959) did not report conodonts from the Galena at Pikes Peak, his study and th is one complement each other in th e ir coverage of the

Middle Ordovician rocks of northeast Iowa,

Tne Glenwood Shale of Minnesota contains elements of Phragmodus inflexus (Stauffer, 1935a; Webers, I 966) and yields a variety of fibrous conodont-elements, many of which are referable to Chirognathus.

40 41

The overlying P la tte v ille Formation contains elements of Phragmodus

coznitus and Oulodus se rra tu s . DJhich occur both below and above the

upper boundary of the "zone" of Phragmodus in flex u s. Phragmodus

undatus is first recorded in the Carimona Member of the Platteville

(Webers, I 9ÔÔ) Phragmodus cognitus and Oulodus se rratu s are not knoivn

in the Pikes Peak section belovr the highest foot of the Platteville

Formation. P. undatus is represented from the middle of the

Guttenburg Member of the Decorah to the top of that part of the

Pikes Peak section that was sampled. Samples from the Van Driest

Core, Sheboygan County, Wisconsin, produced elements of P. cognitus

from every sample of the lower 55 fe e t of the P la tte v ille Formation,

Elements of Oulodus serratu s are present in one sample in the midportion

of the Decorah Formation, Phragmodus undatus is represented in every

sample from the middle of the Decorah to the middle of the Galena,

The conodont fauna of the Copenhagen Formation of Nevada (Ethington

and Schumacher, 19Ô9) contains few elements in common vrith Black River

faunas of the eastern Midcontinent, Belodella r.iger, which is present

in the Copenhagen, is represented only in the Pierce and basal Ridley

lim estones of Tennessee, The presence of elements of Phragmodus to rtu s

(identified as P, undatus by Ethington and Schumacher) in d icates th a t

the Copenhagen is older than th e Phragmodus inflexus "zone" and thus

older than most of the sections sampled here,

Conodonts from the Joachim Dolomite of Missouri have been studied

by Branson and Mehl (1933) and Andrews (I 967), However i t is n ot

possible to determine the exact stratigraphie levels from which the 42

material studied by these authors was collected. All laminar elements

described by Andrews were derived from the upper Joachim at his

localities 3, 9» and 11 , except for an unspecified number of elements

of the form-species Subeordylodus delicatus from the Ixfer Joachim at

his locality 6. Samples from /indrews' lo c a litie s 8, 9» and 11 are

dominated by elements of Phragmodus in fle x u s, Pleetodina acu leata, and

Panderodus g ra c ilis and th erefo re belong in the Phragmodus inflexus

"zone," The stratigraphie value of fibrous elements has not yet been

w ell defined. However Chirognathus is lacking in the Joachim and th is

suggests th a t i t is re s tric te d to the upper p a rt of the Phragmodus

inflexus "zone,"

The P la ttin Group, : 7hich directly overlies the Joachim, was well

■ sampled at Batchtœm Quarry, Illinois, and the fauna matches that described

by Branson and Mehl (1933) fron rlisso u ri. The Dutchtoi-m fauna described

by Youngquist and C ullison (1946) is mostly fib ro u s. The presence of

elements of /h'ltioistodus and absence of Chirognathus suggests that

i t is e n tire ly older than the in te rv a l sampled in Batchtovrn Quarry,

(Sweet and others, 1971; W, C. Svreet, personal communication). The

presence of Phragmodus to rtu s and Leptochirognathus t i e the Dutchtovjn

to the Mclish and Tulip Creek Formations of Oklahoma and in d icate th a t

i t i s older than the Phragmodus inflexus "zone" and th e Black River Group.

The P r a tt Ferry fauna described by Sweet and BergstrBm ( I 962)

contains little in common vrith the Black River fauna. Pratt Ferry

conodonts are largely European species and those of the Stones River

Group of Tennessee, th e c lo se st section sampled in th is study, are 43 dominantly of Midcontinent type. Belodina compressa. Dreoanoistodus suberectus. and Panderodus ?racilis are the only species represented in both sections, and they are all long-ranging Ordovician species.

The Pratt Ferry is probably older than the outcropping Stones River

Group of the Central Basin of Tennessee. That is, tie Pratt Ferry falls entirely within the Pygodus serras Zone (Bergstrom, 1971). The

Chazy Group of Hew York corresponds to the upper Pygodus serrus Zone and th e Pygodus anserinus Zone, The overlying Black River Group must be younger, and th e Stones River Group of Tennessee, which is equivalent to the type Black River is therefore younger than the Pratt Ferry.

The Deer Island Member of th e Winnipeg Formation of Manitoba contains conodonts (Oberg, 1966) referable to Pleetodina aculeata.

Drepanoistodus suberectus, Panderodus panderi and P. gracilis. The single phragraodiform element knoim from th is u n it is undiagnostic.

However the presence of a chirognathiform element associated irith P. aculeata suggests a co rrelatio n wdth the Glenwood of I-Iinnesota and the

Platteville of Iowa.

Conodonts of the Harding Sandstone of Colorado were studied in detail by Sweet (1955). The fauna represented is dominated by representatives of Pleetodina aculeata, Chirognathus monodactyla,

Curtognathus typus, and C. expansus . The single phragmodiform element in these Harding collections is undiagnostic. The Harding is probably equivalent to the Glenwood of Minnesota, the Platteville Formation of

Iowa, and the Platteville of Illinois and Missouri. 44

Sandstones beneath the Bighorn Dolomite of Wyoming (Amsden and

M iller, 1942) contain elements of Chirognathus monodactyla and

Erismodus radicans but the Lander Sandstone Member at the base of the dolomite sequence yields upper Ordovician conodonts and megafossils.

The lower sandstone series is equivalent to the Harding Sandstone of

Colorado, Stone and Furnish (1959) recovered conodont-elements from the upper Bighorn that indicate this portion is definitely younger than Black River rocks and their lateral equivalents. mDDLE OHDOVICIM CORRSUTION COÎdPARISONS

Two major middle Ordovician co rrelatio n s fo r North America have been proposed, one by Ti-renhofel and others (195^) and another by

Cooper ( 1956). Kay (19%) in his proposal of the Bolarian Series, proposed a correlation of the Mddle Ordovician of the Appalachians,

Kentucky, and Ne'v York. Bergstrom (1971) compares Appalachian sections in d e ta il including Cooper’s reference sectio n s, Templeton and Willman

(1963) describe detailed correlations based on lithologie similarities from Illinois to most of the sections included in this study. The correlations suggested in this study (Text-fig. 28) contain some revisions of all of these earlier correlations of the eastern îdidcontinent

Black River Group and equivalents.

Roaring Brook, Lo',rville, New York.—The Standard Reference section for the ÎÜddle Ordovician (Champlainian) had been in New York until

Cooper ( 195^) proposed five stages from the Central and Southern

Appalachians, and Nevada, based upon brachiopod faunas. E a rlie r Kay

(194-7) had proposed the Bolarian Series, but i t has not received vn.despread acceptance. Cooper’s stages have been shovm to overlap

(Bergstrom, 1971). The conodont faunas of the Black River Group in this collection contain many long-ranging elements and are not d is tin c tiv e , i-diich poses problems in adequate regional co rrelatio n s.

Elements of Phra?modus undatus are represented in the lowest Selby in this collection, and Schopf (I 966) reported this species from the 45 46

uppermost Watertoi-m Formation in New York. Barnes (19^7) has demon­

strated that this formational contact may be in part a facies relation­

ship, The presence of Phragmodus inflexus in the Pamelia of New York

(Sweet and o th ers, 1971) and the f i r s t appearance of P. undatus above

the top of the type Black River would strongly.suggest that all of

th e type Black River Group belongs in the "zone'- of Phragmodus

in flex u s.

Kay (1943) indicated that the Bolarian Series includes pre-Pamelia

strata that are younger than Chazyan, and post-./atertown rocks that

are older than Selby, Cooper placed the Black River Group in th e lower

Wilderness, unconformably overlain by the Selby, which is upper

Wilderness, These correlations can neither be supported nor denied

. from a study of conodonts because the extreme differences between

conodont faunas from the type Black River Group and those from

presumably equivalent strata in the Appalachians, Schopf (1966) placed

the Wildemess-Barneveld boundary at the Kirkfield-Shoreham boundary.

He suggests a division of the Wilderness Stage that coincides vdth the

Watertown-Selby boundary. The presence of elements of Curtognathus

robustus, C, exDsnsusi and Erismodus radicans in the Black River Group

and their virtual absence in the Selby suggests this division. It is

fu rth e r supported by the low est appearance of elements of Phragmodus

undatus in the highest Watertovm, No conodont-elements of European

affinities (in the sense of Schopf, I 966) are present in the Black

River Group collections of this study as they are in the overlying

Trenton Group (Schopf, I 966), 47

Kentucky,—The Oregon and Tyrone limestones were placed in the

Trenton Stage by Tc'Jenhofel and co rrelate d :fith the lower Trenton

Group of Hew York. Cooper hoiiever placed the Camp Nelson Limestone

in the upper Wilderness also and equivalent to the Trenton Group,

These correlations differ frcan those suggested in this study and those

of Sire et and Bergstrom (1971)» based upon the conodont faunas.

Occurrences of Phra~raodus undatm in th e upper 6 fe e t of th e Tyrone

Limestone end in the basal Selby of Hew York indicate the level of the upper boundary of the Phragmodus inflexus "zone," Thus most of the

Tyrone, all of the Oregon, and most of the Camp Nelson Limestones c o rre la te i-rith the Black River Group of Hew York, The lower portion

of the Camp Nelson, not exposed to the surface, correlates with similar

strata in the subsurface of Qiio in the Pan American Davidson core, where th e base of the "zone" of Phragmodus Inflezcus is defined. Thus the lower portion of the Camp Nelson is older than the Black River, though i t may be younger than the type Chazy Group, Templeton and

Willman (I 963) correlate the Tyrone, Oregon, and Camp Nelson Limestones with the Platteville Formation of Illinois, Undoubtedly the lower

Camp Nelson is older than the lower P la tte v ille and Glenwood,

Centra]. Basin, Tennessee,—Cooper (195^) placed the base of the

Trentonian Stage at the base of the Hermitage Formation and the base of the upper half of the Wilderness at the base of the Carters

Formation, The Murfreesboro has been included in the Porterfield stage below th e Wilderness by Cooper (1955), Ti-:enhofel and others

(1954) assigned the Carters to the Trentonian Stage and the remainder 48

of th e Stones River Group to th e Black River an. Templeton and Willman

(I9Ô3) correlated the whole of the Stones River Group with the P la tte -

v il le and Ancell Groups of I ll in o is , which are Black Riveran in age,

■ VJhile the conodont fauna does not rule cut this last correlation, the

author suggests that the Murfreesboro of Ternessee is older than the

Glenwood Shale of n o rtheast Iowa and northern I ll in o is . C orrelation

of the I'Surfreesboro vriLth the lower part of the Camp Kelson of the

subsurface of Kentucky and vrith the Gull River of the subsurface of

Ohio suggests that these units are ir the interval dominated by Fauna

6 of SiJeet and others (1971) and are thus older than the Phragmodus

inflexus "zone." The remainder of the Stones River Group belongs in

this zone. The top of the zone is. defined by the occurrence of P.

undatus in sang>les from the base of the Hermitage (undescribed

collections of Dr. Walter C. Sweet, The Ohio State University).

Coboconk, O ntario.—The section exposed a t Coboconk, O ntario, was

included in the Black Riveran by Tî-renhofe l and others (1954-) and the

overlying Bobcaygeon Formation in the Trentonian. Cooper (1956)

indicated an lower Wilderness age fo r the Shadow Lake and Gull River

Formations and upper Wilderness fo r the Bobcaygeon. Although no key

species are represented in the writer’s collection from these rocks,

Schopf ( 1966) recovered elements of Phragmodus undatus from the middle

Member of the Bobcaygeon# Thus th e irrite r co rrelate s the Shadow Lake,

Gull River, and the lower member of the Bobcaygeon Formations with the

type Black River Group of New York.

Grand Cloche Islan d , O ntario.—Twenhofel and others (1954') place 49 the Sviift Current and loizer Cloche Island beds in the Black Riveran and the upper Cloche Island in the Trentonian, Cooper (195^) relegated the S ifift Current to the Black River Group of New York, and the Cloche

Island to the upper Wilderness, Trenton Group of New York, The author’s collection contains dichognathiform and oistodifom elements of

Phragmodus undatus 5 fe e t above the base of the Cloche Island, A ll the strata beneath that level are considered to be equivalent to units of the P. inflercus "zone" and correlative vdth the Black River Group of

New York, The remainder of the Cloche Island containing elements of

Fauna 8 (Sweet and oth ers, 1971) is equivalent to the Trenton Group of

New York, th e Le:cington Limestone of Kentucky, and the Hermitage of

Tennessee.

Bony Falls, Michigan,—A thin stratigraphie section, exposed at

Bony F a lls, D elta County, I«îichigan, contains an assembly of conodonts dominated by representatives of Phragmodus infle>ais and Pleetodina aculeata and belongs in the P, infle:ois "zone," It is therefore equivalent to a p a rt of the Black River Group of Mew York, Kay (1937) considered this sequence to be a Selby Formation equivalent; however

Templeton and W illman-(I 963) and Ti-renhofel and others (1954) correlated this unit with the Platteville Formation of Illinois, which also contains elements of Fauna 7 (Sizeet and oth ers, 1971). Cooper (1955) did not mention the Bony Falls beds in his study.

Southeastern, Minnesota.—Webers (19o6) published a comprehensive study of Middle and Upper Ordovician conodont elements from southeast

Minnesota, The section had been studied in part by Stauffer (1935%, 1935b), 50

Cooper ( 1956) considered the Glenirood Shale and the lower h a lf of the

Platteville to be lower Wilderness and equivalent to the Black River

Group, The upper P la tte v ille and Decorah were correlated %d.th the

Trenton Group, upper Wilderness in age, Ti^enhofel and others (1953) follows Kay’s ( 19^8) correlation, equated the Glenwood and Platteville with the Black River Group, The Decorah was considered a Trenton equivalent, Teirç)leton and Willman ( 1963) concurred Tdth the cor­ re la tio n of Kay ( 1943), The conodont-elements described by Webers suggest a major revision of these co rrelatio n s. Only the Glenwood

Shale and the McGregor, the lower member of the P la tte v ille , belong in the P, infle:cus "zone" and are equivalent to the Black River

Group of New York, the Camp Nelson-Tyrone sequence of Kentucky, and the Stones River Group of Tennessee, The upper Platteville, the

Decorah and the lowermost Galena contain representatives of Fauna 8

(Sweet and oth ers, 1971) and are equivalent to the Selby and lower

Kirkfield Formations of New York. The Galena Formation, from the lower Cummingsville to upper Stewartville, contains elements of

Fauna 9 and is equivalent to the upper K irk field , Shoreham, and lowermost Denmark of New York and a portion of the Lexington Limestone of Kentucky,

Pikes Peak, Iowa,--Here again Ti-renhofel and others (195^) follow

Kay’s (1948) correlation. The Platteville Formation is Black Riveran and the Decorah Formation is Trentonian, Cooper’s (1956) correlation i s the same. The co rrelatio n from northwest I llin o is to New York by

Templeton and Willman (19o3) is much th e same. The w rite r’s collectio n 51 of conodont-elements supports the previous correlations, since the upper boundary of the P. inflexus "zone" is defined by the .occurrence of P. undatus in the lowest exposed beds of the Decorah Formation.

Batchto^-m Quarry, I l l i n o i s .—Cooper (1955) placed the lower half of the Plattin Group in the lower Wilderness, and the upper half in the upper Wilderness, equivalent to the Trenton Group of New York,

The Dutchtovjn and Joachim Formations vrere considered to be Ashby in age. Twenhofel and others (195^) however, put the Joachim in the

Chazyan and a l l of the P la ttin Group in the Black Riveran. The conodont fauna closely supports the correlations of Twenhofel and others (195^)» for exposures of the Plattin up to the uppermost Quimbys Mill at

Batchto-.jn Quarry, I ll in o is , belong in the P. inflexus "zone." The base of the "zone" is not recognized at this exposure, but it is at le a s t as lovr as the upper Joachim, vrhich qlsewhere contains elements of P. inflexus (Andrews, 19o?). The uppermost Quimbys M ill contains elements ct Oulodus se rra tu s. vrhich ranges upvrard from near the top of the P. inflexus "zone" into younger rocks with representatives of

Fauna 8. Thus the top of the P la tte v ille Group exposed in the Batch- town Quarry i s probably near the upper boundary of the Phragmodus inflexus "zone." SYSTHUTIC PALEONTOLOGY

Genus ACODÜS Pander, 1856

Acodus PANDER, 1856, p. 21,

Type Species,—Acodus erectus PANDER, 1856,

ACODUS I-flJTATUS (Branson and Mehl)

PI, 3, figs. 1, 2, 3; Text-fig, 4A-C.

Belodus (?) mutatus BRANSON AND MEHL, 1933» P. 126, P l, 10, fig . 1?,

Acodus i nom atus ETHINGTON. 1959, p. 268, P l. 39, f ig . 11; ETHINGTON AND FURNISH, 1962, p. 1259, 1260; SCHOPF, 1966, p. 31, Pl. 5, fig, 20, Text-fig, ?a,

Distacodus procerus ETHINGTON. 1959, p. 2?5, Pl. 39, fig. 8; ETHINGTON AND FURNISH, 1962, p, 1256; SCHOPF, 1966, p, 51, Pl. 5, fig. 1, Text-fig. 7b,

Acodus («'Belodus (?)") mutatus (Branson and Mehl), BERGSTROM, 1964-, p. 9, 10, Text-fig, 2,

Acodus mutatus (Branson and Mehl), BERGSTROM AND ff-/SET, 1966, p, 303, 304, Pl, 35, fig. 7-9; V/EBERS, 1966, p, 21, Pl, 3, figs, 5, 6; SERPAGU, 1967, p , 13 , 14, Pl, 6, figs, la, lb, 6a, 6b,

Distacodus? trigonius SCHOPF, I 966, p, 52, 53, Pl. 5, figs. 2, 3, 4,

Three d iffe re n t forms are here included in Acodus mutatus. The first type are elements of the typical form-species A, mutatus (Pl, 3, fig, 1; Text-fig, 4A), which are simple, recurved, symmetric cones with a basal cavity that penetrates about one-third the cusp height. The second type of elements (Pl, 3, fig, 3; Text-fig, 4B) are asymmetric, recurved sir^le cones, that are concave on one side, convex on the other, slightly keeled on the anterior margin, and with a deep basal cavity. The third type of element (Pl, 3, f ig , 4; T ex t-fig , 4c) is 52 o d B

T ext-fig. 4A-C. Acodus mutatus (Branson and Mehl). Lateral views and cross-sections; dotted lines outline the basal cavity. (A) Typical element of the form-species A. mutatus, (B) an asymmetric simple cone with an inflated inner lateral basal margin, (C) a symmetric simple cone with two antero­ lateral costae. 54

similar to the ones described by Schopf (1966) as Distacodus?

trigonius. The cusp is sharply recurved near the apex, has two

antero-lateral costae, a deep basal cavity, and a triangular cross-

sectio n . Occurrence « —The collections at hand contain 44 specimens of this

species from th e P ierc e, Ridley, Lebanon and lower Carters Formations

of the Central Basin of Tennessee, Sanples from the Platteville Forma­

tio n a t Pikes Peak, Iowa, produced 14 specimens, Acodus mutatus has a

wide geographic distribution; it is knovm from the Galena of loiia

(Ethington, 1959)» the Maquoketa of loî^a (G lenister, 195?)» and the

Galena, Dubuque, and Maquoketa of Minnesota (Webers, 1966); from the

Lexingtcai and Kope Formations of Kentucky and Ohio (Bergstrom and Sweet,

1966); and from the Trenton Group of New York and southern Ontario

(Schopf, 1966),

Repository. —Hieropaleontological co llectio n s. The Ohio State

University, Reference slides—7OVL-3» 4, ?; 70VJ-2, 22; 70VM-3, 4, 5,

9; 7OVH-2 , 6, 7» 9 , Figured specimens—OSU 29600-29602.

Genus ACOKTIOEOS Pander, I856

Acontiodus PANDER, 1856, p, 28,

-Type Species.—Acontiodus latus PANDER, I 856,

The nature of the skeletal apparatus of the type species of Acontiodus

i s not known. Hence i t is here used as a form-genus, to which a single

form-species is referred. ACOHTIODDS ALVEOURIS S tauffer

Pl. 2, figs. 15, 21.

Acontiodus alveolaris STAUFFER, 1935b, p. 601, 602, Pl. 74,„fig. 44; ETHINGTON, 1959, p. 268, P l. 39, fig s . 23, 24; BERGSTROM AND SV3EET, 1966, p. 306, Pl. 35, figs. 16-19; IVEBERS, 1966, p. 22, Pl. 3, f ig . 3; ETHINGTON AND SCHUMACHER, 1969, p. 449, 450, P l. 6?, fig. 25.

Acontiodus n. sp. BRANSON, 1944, p. 89, 90, Pl. 13, figs. 12, 13 (not Pl. 13, figs. 9, 10). Elements here referred to Acontiodus alveolaris may be parts of the

skeletal apparatus of a multielement species, that also contained elements

referab le to the form-genera Acodus and Distacodus. In seven of th e

eight Black River sanples that contain two or more representatives of A.

alveolaris. there are also elements'of either Acodus mutatus or Distacodus

fa lc a tu s.

Occurrmce.—Acontiodus alveolaris , although rare in the sections

considered in this study, is widely distributed throughout the Eastern

Midcontinentv Ten specimens were recovered from the P la tte v ille Formation

a t Pikes Peak, lot-ra; the P ierce, Ridley and Lebanon lim estones of th e

Central Basin of Tennessee yielded 19 elements of the species; the Platte­ v il le Formation in th e Van D riest Core, Sheboygan County, Wisconsin produced a single element from one small sangle; and th e Nachusa Formation at Batchtcnm Quarry, Illinois yielded one representative, A. alveolaris is knovai from the Lexington and Kope Formations of Kentudcy and Ohio

(Bagsbrom and Sweet, 1966), th e Glenwood to upper Dubuque of Minnesota

(Webers, I 966), the Prosser of Iowa (Ethington, 1959) and the Kimraswick of

Missouri (Branson, 1944). Repository,—»>îicyopaleontological collections, The Ohio State

U niversity. Reference Slides.~70V L-^; 70VJ-24-26; 70VK-2, 6;

71Z^-I029î 70VH-2-4, 6; 70VI-17. Figured specimen.—OSU 29603

Genus APPAUCHIGNATHUS Votaw n . gen.

Type Species. —Appalac?dgnathus d elicatu lu s VOTAW, n , sp.

Only one species of th is new genus i s known, hence th e diagnosis of th e genus is the same as the following diagnosis of its type species,

Appalachignathus delicatulus. From discussions vdth Dr. Stig Bergstrom, of the Ohio State University, the author bece.me aviare that the elements of this genus have been knoin to Dr. Bergstrom and Dr. Perry Vdgley for some time. Dr. Bergstrom has suggested the multielement apparatus and the name for the genus described as Appala chi enathus.

APP/ilACHIGNATHUS DELlC/iTUIUS Votaw, n . sp.

Pl. 3, figs. 37-39, 46; Text-fig. 3^-D.

ÎOepikodus a f f . p. cooenhagenensis ETHINGTON AND SCKUI^ACHSR, 1969, p. 4^5, 466, Pl. %T, fig.^l4; Text-fig. 41,

New Genus B ETHINGTON AND SCHUiaCHER, I 969, p. 479, Pl. 67, fig. 18; Text-fig, 4a.

Diagnosis. —Appalachignathus delicatulus is a multielement species th e sk e le ta l apparatus of which was composed of a t le a s t four elements

Three of these compose a form-transition series that grades from a symmetrical tiichonodelliform element through a zygognathiform element to an eoHgonodinifoKn element, that is one vdth posterior and lateral denticulation on the cusp. The fourth element is a strap-like falodiform Text-fig. 5A-D. Appalachignathus delicatulus Votaw, n. sp. (A) L a teral view of a falodiform element, (B) la te r a l view of the eoligonodiniform element, (C) postero-lateral view of the zygognathiform element, (D) posterior view of the trichonodelliform element. 58 element the.t has a long anterior process Tilth compressed and confluent denticles and no posterior process.

The trichonodelliform element (Pl. 3j fig, 39; Text-fig. 5D) has has denticulate lateral processes and an undenticulate posterior process, which bears a median groove that extends up to the base of the cusp.

Lateral denticles are small, compressed and overgrown for half their height. The basal cavity penetrates to one-third of the cusp height and extends as a groove under the lateral processed.

The zygognathiform element (Pl, 3> fig. 38; Text-fig. 5C) is essentially a distorted trichonodelliform element, A lateral process is well developed on one side but on the other bears only two or three denticles. The posterior process is undenticulate and does not bear a median groove as does the trichonodelliform element. The basal cavity penetrates about one-third of the cusp height and extends under the posterior process and the well-developed lateral process as a sheathed groove.

The eoligonodiniform element (Pl. 3» fig. 37; Text-fig. 5B) in the transition series has a finely denticulate posterior margin that merges viith a strongly reclined cusp. The lateral process bears denticles similar to those of the other elements. The basal cavity penetrates one-half of the cusp height and is drawn out into a peak at its upper termination.

The falodiform element (Pl. 3» fig. Text-fig. 5i) is quite distinct. The basal cavity, which is shalloif and penetrates only the base 59

of the cusp, is well sheathed m conç>lete specimens and continues under

the anterior process as a shallots groove. The cusp is reclined and

forms an acute angle vdth the posterior margin. Denticles on the

anterior process are nearly as large as the cusp, are laterally con^jressed,

and laterally confluent for half their height. As many as 20 denticles

may be developed on the anterior process. The element is not symmetrical

but s lig h tly bowed.

Occurrence.—Appalachignathus delicatulus is a widespread species.

I t is represented in the upper 15 feet of the Murfreesboro, throughout

the Pierce, and in the lovrer 20 feet of the Ridley Limestone of the

Central Basin of Tennessee; it occurs in the loifer 95 feet of the Camp

Nelson Limestone at its type section and in the lower 223 feet in the

Condnco Core of n o rth -c en tral Kentucky; i t i s represented in Middle

Ordovician limestones in a core in Richland County, Ohio; and it is

known from the type Ashby of Hogskin Valley, Tennessee, which is

p resen tly under study by Mr. Jack Carnes of the Ohio S tate U niversity,

A. delicatulus has a known range from the base of the type Ashby into

th e lower p a rt of th e Phragmodus inflexus "zone". E3.ements sim ilar to

some of th e components of A, d elicatu lu s have been reported from the

Copenhagen Formation of Nevada (Ethington and Schumacher, I 969) . The

w riter’s Black River samples produced only 111 idiole or essentially

complete specimens, but fragments of the falodiform elements are abundant

and readily recognizable. Elements of A, delicatulus make up 0,42 percent

of the collection at hand. Repository.--Mcropaleontological collections, T.he Ohio State

University, Reference sections,— 7OVK, ?OVL, ?OVJ, ?07, 7OZA., 65X.

Syntypes.—OSü 29604-29607 ; ünfigured paratypes, OSU

29608-29611

Genus BELODELIA (Ethington), 1959

Belodus devonicus Stauffer, 19^, p, 240,

Type Species,—Belodella devonica (STAUFFER), 1940,

Diagnosis,—A small number of belodellifoim and oistodiform

elements, unlike any others in this lliddle Ordovician collection, are present in the suite of sarroles from the Pierce and basal Ridley limestones collected at Piercers 14111, Tennessee, Dr, Stig Bergstrom has suggested to the vrrlter on the basis of much larger Appalachian

collections, that these elements are part of one apparatus, A forra- transition series of belodelliform elements is present, and these

elements are more common than the oistodiform elements in this small

collection. As these elements do not occur in any other section sampled

for this study, Belodella niger is very likely not a conponent of the

MLdcontinent fauna, •

BELODELLA. NIGER (Serpagli)

Pl, 3, figs, 6-11; Text-fig, 6A-D

Oistodus niger SERPAGII, 19^7» p. 79» 80, Pl, 20, figs, la-7d,

Oistodus sp, LINDSTROM, 1959, p. # 0 , 441, Pl, 3, fig. 13. 61

Oistodus sp. SERPAGII Aî® GRBCO, 1965, p. 203, Pl. 35, flgs. 7, 8.

Oistodus breviconus Branson and Mehl. EAI#R, 1966, p, 63, Pl. 1, fig. 19.

Belodella erecte (Rhodes and Dlneley), SERPAGII, 1^6?, p. 5^, Pl, 11, figs, la-6c,

Î Oepikodus copenhagenensis BTHimTON AND SCHÜÎi/lCHER, 1969, p. 465, Pl. 68, figs. 5, o, TexUfig. AL.

Oistodus nevadensis ETHINGTON AND SCHUMACHER, 1969, p . 46?, 468, Pl. 68, figs. 1-A, Ta:d>fig. 50.

New Genus A, ETHINGTON KW SCHüîaCHER, I969, p. 4?8, 4?9, Pl. 68, fig. 12, Text-fig. AJ.

«Eoligonodlna» s p ., ETHINGTON AI® SCHUIiACHER, I 969, p. 480, Pl. 68, fig. 1?.

Belodella sp. A, FAHRAS08, 1970, p. , Pl. , figs.

Samples from the Pierce Limestone and the basal Ridley Limestone, at their type sections in the Central Basin of Tennessee, contain 81 belodelliform and oistodiform elements that are quite distinct from any others in my 1-B.ddle Ordovician collection. Dr. Stig Bergstrom has worked out the elements of the skeletal apparatus of the species on the basis of extensive Appalachian collections. These elements have been placed in the same species because of their similar size, pnique denticu­ lation, deeply penetrating basal cavity, and stratigraphie occurrence.

This collection contains very few representatives of the species, thus no ratio of elements in the apparatus can be suggested.

The oistodiform element, which is indistinguishable from those described by Serpagli (I 967) as Oistodus niger as from those named

Oistodus copenhagenensis by Ethington and Schumacher ( 1969)5 i s asymmetric and has a slightly reclined cusp that meets the posterior 62

Text-fig. 6A-D. Belodella niger (Serpagli). (A-C) Lateral views of three belodelliform elements, (D) lateral view of the oistodiform element. 63 margin of the base at an angle of approximately 30 degrees. The basal

cavity does not penetrate the cusp but is confined to the base and is deeply sheathed. The base i s more in fla te d on one side than on th e

Belodelliform elements form a transition series from a symmetric element (Pl, 2, fig, 9; Text-fig, 6A) to another symmetric element

(Pl, 2, figs, 10, 11; Text-figs, 6c) to an asymmetric element (Pl, 2, figs, 7> 8; Text-fig, 6 b). The first-mentioned belodellifozm element has a proclined cusp and hair-like denticles confined to the upper margin of the base. It bears two costae along the lower margin of the base that extend onto the cusp. The basal cavity penetrates only as far as the base of the anteriormost denticle on the upper margin of the base. The other symmetric belodelliform element has a more proclined cusp and denticles that extend along the posterior margin of the cusp.

I t also has two costae on the loiter margin and the basal cavity extends about one-half the length of the element. The asymmetzio belodelliform element is nearly planar on one side and convex on the other. Hair­ like denticles are developed along the upper margin of the base but are not present on the posterior margin of the proclined cusp. The basal cavity penetrates the cusp beyond the base of the anterior most denticle and terminates at the lower anterior margin.

Occurrence,—Belodella niger is known from the Pierce and basal

Ridley Limestones of Tennessee, th e Copenhagen Formation of Nevada

(Ethington and Schumacher, 1969)» from the Ashgillian strata in the 64

Camic Alps (Serpagli, I 967) , from th e Crug Limestone, Wales

(Lindstrom, 1959)» and from the Middle Ordovician of the Oslo region,

Norway (Hamar, I 966).

Repository.—»Mioropaleontological collections. The Ohio State

University. Reference Slides.—70VL->S; 7OVJ-I, 4. Figured hypo- types OSU 29612-29615

Genus BELODINA Ethington, 1959

Belodina ETHINGTON, 1959» p . 271.

Eobelodina Sl-JSST AND OTHERS, 1959» p. 1051.

Type Species, Belodina compressa (BRANSON AND MEHL), 1933.

BELODINA COMPRESSA (Branson and Mehl)

PI, 3» figs. 36» 40, 41.

Belodus compressus BRANSON AND MEHL, 1933» p. 114, P I. 9» fig s . 15» I 6.

Belodina compressa (Branson and Mehl) . BERGSTROM AND S^VZET, I 966, p . 312 - 315» P I. 31 » fig s . 12-19 (includes synonymy through I 966); B/iRNES, 1967» p. 236; 'ÆYANT, 1968, p. 36, 37» PI. 2, fig. 6.

Belodina diminutiva (Branson and Mehl). BARNES, I 967, p. 236.

Belodina grandis (Stauffer). B/iRNES, p. 236; VJEYANT, I 968, p. 38, PI. 2, fig. 1.

Eobelodina fom icala (Stauffer). BfiRNES, I 967, p . 236; WEYANT, I 968, p . 49, 50, PI. 2, fig. 7.

IBelodina dispensa (Glenister). WSYANT» 1968, p. 37» PI. 2, figs. 2, 3.

Belodina monitorensis monitorensis ETHINGTON AND SCHUMACHER, I 969, p. 4^, PI. 67, fig s , 3, 5, 8, 9, Text-fig. 5D. 65

Belodina compressa is a long-ranging species, present from

Middle Ordovician up into rocks of lower Maysvillian age in Ohio

(Pulse and Sweet, I960) and into Ashgillian strata of Sxreden

(Bergstrom and Sweet, 1966), The lowest r^orted occurrence of representatives of the species is in the Pratt Ferry fauna of Alabama

(Svjeet and Bergstrom, 1962), The author found elements of this species as low as the base of the Pierce Limestone in the Central Basin,

Tennessee, Similar elements are also present in the Gang) Nelson limestone, ju s t below th e highest occurrence of Phragmodus inflexus; near the top of the Pamelia Foimation of New York; and near the top of the Gull River

Formation of the Ontario Lowlands, Specimens of B, compressa have been collected from 25 feet above the base of the Svjift Current Beds of the

Cloche Island area of western Ontario, The Bony Falls beds of the Upper

Peninsula of Michigan contain representatives of this species in half the samples. It is present in the Platteville, Decorah, and Galena Formations in th e Van D riest Core in ^-B.sconsin and in every sample of th e P la tte v ille and Decorah Formations collected at Pikes Peak, Iowa, Sait^les from

Batchtovjn Quarry, Illinois, contain elements of B, compressa 7 feet above th e base of the Grand Detour Formation, Thus the lov/er lim it of the known range of the species appears to be the Pratt Ferry Formation,

Alabama, Elements of the species are associated with those of Plectodina aculeata and Phragmodus inflexus in the Murfreesboro Limestone of

Tennessee at a level that seems to represent a point low in the "zone” of

Phragmodus in flex u s, B, compressa i s present in every section sampled 66 for this study except 65X, a short core from the subsurface of Ohio immediately at the base of the Gull River above the Knox Dolomite,

A total of 1261 belodiniform and 126 eobelodiniform elements are present in the author’s collection, a ratio of 10;1, This suggests that the skeletal apparatus included a total of 22 elements in this ra tio , Bergstrom and Sx;eet (1966) suggested a ra tio of 8:2 fo r th e ir collections, while Schopf (I 966) found these two elements in a ratio of

10; 2, as did Webers (I 966) in his collections from the Ordovician of

Minnesota,

Repository, —M icropaleontological co lle c tio n s. The Ohio S tate

U niversity, Figured hypotypes, OSU 29616-29618.

Genus BRYANTODINA. S tau ffe r, 1935

Brvantodina STAUFFER, 1935, p. 131.

Type Species, Bryantodina tyoicalis STAUFFER, 1935.

BRYANTODINA? A3RUPTA (Branson and Mehl)

PI, 2, figs, 5, 6; Text-fig, 11,

Ozarkodina (?) abrupta BRANSON AND MEHL, 1933, p. 100, Pi, 6, f ig , 11,

Bryantodina, n, sp, BRANSON, 1944, p, 90, P I, 13 , figs, 34-36,

Brvantodina abrupta (Branson and Mehl), SCHOPF, 1966, p, 44, Pi, 4, fig s , 13 , 14,

Rhlpidognathus paucidentata Branson, Mehl, and Branson, SCHOPF, I 966, , p, 72, PI, 2, fig, 21,

Bryantodina? abrupta (Branson and Mehl), BER5STRŒ1 AND SIÆET, I 966, p. 3I 8- 32 I , P I, 30, figs, 9-12, Text-fig, BA-D, 67

Bryantodîjia? abrupta is represented in the upper 6 feet of the

IÇyrone Limestone of the Jessamine Dome of Kentucky, Three specimens were recovered from the base of the Cloche Island Beds, described by

Liberty (195^) > on Cloche Island, Ontario, The species is also represented in the present collections by one specimen from the Galena

Formation, in th e Van D riest core, Sheboygan County, liB.sconsin and by one from the Decorah Formation at Pikes peak, Iowa, Bergstrom and

Sweet (1966) reported B,î abruota from the Lexington Limestone and the

Kope Formation of Kentucky and Ohio, I t is known from the Kirkfield

“formation" of Nevr York and Ontario (Schopf, 1966) and elements similar to B,? abruota have been reported from the Joachim Dolomite (Branson and

Mehl, 1933) and the Kimmswick Formation of Missouri (Branson, 1944),

Repository,—Micropaleontologic collections. The Ohio State

University, Reference slides, 70V-36-38, 70VB-12, 712^-1077, 70VH-9.

Figured specimens, OSU 29619,^

Genus CHIROGIiiTHUS Branson and Mehl, 1933

Chirognathus BRAMSON AND MSHL, 1933, p. 29.

Chirognathus vjas established as a form-genus by Branson and Mehl

(1933) for fibrous conodont-elements, which consist of a hand-shaped u n it w ith den ticles of varying le n g th , Webers ( I 966) suggested that several of the form-species of Chirognathus are parts of the skeletal apparatus of a single species and he placed them in an informal group.

These elements are part of a form-tra.isition series and are here includedjn one b iologic u n it. From th e small co llectio n a t hand, i t is 68 not possible to determine if additional elements belong to the skeletal apparatus suggested by Webers, The genus appears to be of stratigraphie significance.

Type Species. Chirognathus duodactylus BRANSON AND MEHL, 1933*

CHIROGNATHUS MONODACTÏLÜS Branson and Mehl

PI. 3, figs. 29 , 30 , 34, 35; Text-fig. 7A-G.

Chirognathus monodactyla BRANSON AITD MSHL, 1933, P. 29, 31, PI. 2, figs. 11, 13; fay , 1952, p. 80; ST/EET, 1955, p. 239, PI. 27, fig. 20; WEBERS, 1966, pp. 55, 56, PI. 5, fig. 5.

Chirognathus multidens BRfiNSON AND IffiHL, 1933, p. 34, PI. 2 , f ig , 43; FAY, 1952, p. 79; S’.ffiET, 1955, pp. 235, 236, P l. 27, f ig . 15; WEBERS, 1966, p. 56, PI. 5, fig. 2.

Chirognathus admiranda STAUFFER, 1935a, p. 135, PI. 9, figs. 6, I 6, 22; FAY, 1952, p. 79; S’ÆST, 1955, pp. 235, 236, P I. 27, f ig . 15; WEBERS, 1966, p. 54, PI. 5, fig. 3.

Chirognathus altem atus STAUFFER. 1935a, pp. 135, 158, PI. 9, fig. 31.

Chirognathus delicatulus STAUFFER, 1935a, pp. 136, 158, PI. 9, figs. 1- 3, 5, 7- 13 , 17- 19, 21; FAY, 1952, p . 79; SWEET, 1955, p. 237, P I. 27, fig s . 14, 22; TEBERS, I 966, pp. 54, 55, PI. 5, figs. 1-4; OBERG, I 966, pp. 136, 137, f l* 15, fig . 6.

Chirognathus eucharis STAUFFER, 1935a, pp. I 36, 153, PI. 9, figs. 23, 27, 28, 34; FAY, 1952, p. 80; Si'IEET, 1955, p. 238, P I. 27, fig . 17.

? Chirognathus duodactylus STAUFFER, 1935a, pp. I 36, 158, PI. 9, fig. 29.

Chirognathus expatiatus STAUFFER, 1935a, pp. 137, 158, PI. 9, fig. 4; FAY, 1952, p. 80.

Chirognathus idoneus STAUFFER, 1935a, pp. 137, 153, PI. 9, fig. 24; FAY, 1952, p. 80; SiEET, 1955, PP. 238 , 239, P l. 27, fig s . 8, I 6.

Chirognathus hamatus STAUFFER, 1935a, pp. 137, 158, Pl. 9, fig. 33; FAY, 1952, p. 80. Chirognathus irregularis STAUFFER, 1935a, pp. 137, 138, 158, Pl. 9* fig , 3.2; FAY, 1952, p. 80.

Chirognathus lanesboroihsis STAUFFER, 1935a, pp. 138, 158, Pl. 9, fig. lA; FAY, 1952, p. 80.

Chirognathus raagnificus STAUFFER, 1935a, op. 135, 158, Pl. 9, fig. 25; fay , 1952, p. 80.

Chirognathus radiatus STAUFFER, 1935a, pp. 139, 158, Pl. 9, fig. 15; FAY, 1952, p. 80.

Chirognathus ungulifomis STAUFFER, 1935a, p. 139, 158, Pl. 9, fig. Al; FAY, 1952, p. 81; SVBET, 1955, p. 2A2, Pl. 2?, fig. 21.

?Chirognathus scalenus STAUFFER, 1935a, p. lAO, 158, Pl. 9, figs. 30, 37 , 38; FAY, 1952, p. 85.

Representatives of the forn-species Chirognathus admirandus,

C, d e lic a tu lu s. Ç. laultidens « and C. monodact.ylus were placed in an

Informal group by Webers, (1966) on the basis of similarity of color,

deiticulation, and stratigraphie distribution. The writer does not

hesitate to regard them all as parts of the apparatus of a single

conodont species for the same reasons that Webers cited. That is, they are obviously all members of a form-transition series that grades from

C. multidens to C. monodactylus to C. delicatulus to C. admirandus.

Webers* collection of chirognathiform elements, a l l from th e upper beds of the Glenwood Shale at Lanesboro, Minnesota, suggests a ratio

of 8 delicatulus elements to 2 each of admirandus, monodactylus. and multidens elements, Hor-rever, because the collections at hand contain

only 18 specimens, no ratio of elements is suggested here.

Occurrence. —Only 18 id e n tifia b le chirognathiform elements were recovered from the samples studied, and all are assignable to Chirognathus monodact.ylus. The species is represented in the Ifurfreesboro, Ridley,

Lebanon and lower Carters Formations of the Central Basin of Tennessee; F

T ext-fig. 7A-G. Chirognathus monodactylus Branson and Mehl. Diagramatic views of elements fo the form-species Chirognathus monodactylus (A, C), Ç. multidens (B), Ç. delicatulus (E, F), and Ç. admirandus (D, G), (a fte r Webers, 1966). 71 in the lower half of the Camp Nelson Limestone at the type section,

Jessamine County, Kentucky, and in the subsurface of Mason County,

Kentucky; in the Gull River Formation of the subsurface of Richland

County, Ohio, Elements of the species are present in the upper

Glenwood Shale of Minnesota (S tau ffer, 1935a; Webers, I 966) , in th e loirer shales of th e Vfinnipeg Formation of Manitoba (Oberg, 19^6), in th e Icebox and Roughlock Formations of South Dakota (McCoy, 1952, 1958;

Carlson, I 98O), in the Harding Sandstone of Colorado (Branson and Mehl,

1933; Sweet, 1955)» in th e b asal Bighorn Formation of V^oidng (Amsden and M iller, 1942), and in undescribed Simpson strata from the subsurface of Kansas (Sweet and others, 1971)» Sweet and others indicate that chirognatliiforr: elements are present in strata dorrdnated by Faunas 6 and

7. Chirognathus monodactylus is represented in the I&irfreesboro belcnr th e lowest occurrence of Phragmodus in flex u s. The upper range lim it of

C, monodactylus i s very near th e top of th e Phragmodus inflexus "zone”.

These two species are present in th e Glenwood Shale of Minnesota and

C, monodactylus ranges above the highest P. inflexus in the Central

Basin of Tennessee,.

Repository,—IS.croualeontological collections, Th® Ohio State

U niversity. Reference S lid e s, 70VJ-12, 33; 70VK-7; 7 (#I-4, 6, 8, 13-16;

7OV-I8, 33; 70Zfv-1080; 65x 2- 3915, 3916, 3936, Figured specimens OSU 29620-29623 72

Genus CÜRTOGK/lTHüS Branson and Mehl, 1933

Curtognathus BRANSON AND MEHL, 1933» p. 8?.

Cardiodus BR/iNSON i m MEHL, 1933, p. 80-81.

Polycaulodus BRANSON AND MEHL, 1933, p. 86.

Trucheroenathus BRANSON AND MSHL, 1933, p . 84.

Type Species.—Cartogriathus typus BRANSON AND MEHL, 1933, p. 8?.

Tiro of the Black River species include curtognathiform, cardio- dellifona, polycaulodif orm, erisnodiform and trucherognathiform elements, The author is confident that both represent multielement species. The type form-species of Cardiodus. Polycaulodus. Trucherognathus. and Curtoznathus are parts of one skeletal apparatus. The types are all from the Joachim of I&ssouri, and all but that of Curtognathus are from th e same e:q>osure. As a consequence, Cardiodus. Polycau3.odus. and ______

Trucherognathus are regarded as subjective synonyms of Curtognathus,

Reference of these two multielement species to Gurtognathus automatically broadens the scope of the genus,

Curtognathus was established as a form-genus by Branson and Mehl for elements consisting of a slender arched bar with discrete slender denticles nearly in the plane of the outer edge of the base. They recognized the dose relationship between this form-genus and Trucher- ognathus and Polycaulodus, The trend of some elements to approach

Cardiodus was also indicated by them. It is apparent from the collection at hand (2362 elements) that these elements exist as a form-transition series and intermediate forms exist. Additionally an erismodiform element is present in both species and a microcoelodiform element in one. OJRÎOGÎMHÜS ROBüSTgs (Branson and Hehl)

Pl. 1, figs. 13, 15, 17-19; Pl. 2, figs. 31, 33, 34, 36; Text-fig. 8A-I.

Cardiodus robustus BRANSON AND 14EKL, 1943, p. 382, P l. 64, figs. 23-26.

Cardiodella sp. SCHOPF, 1966, Pl. 6, fig. 14.

Curbognathus? sp. SCHOPF, 1966, Pl. 6, fig. 19.

Trucherognathus sp. SCHOPF, 1966, Pl. 6, fig. l6. This collection contains a series of fibrous raiîdform elenents that have the same stratigraphie range, size, color, basal character and d en ticu latio n . These 856 elements compose 3,21 percent of the co llectio n .

They are not well kncnm from the literature but seem to be closely related in this coUeoticm. Thus the author has no hesitation in placing them in the same biologic u n it, even though they would belong to fiv e different form-genera, if the form-taxonomic approach vrere used.

The erismodiform element (P l. 2, f ig s . 31, 33; T ext-fig, 6A-B) i s an asymmetric coitrolex ramiform element surmounted by a sh o rt, sto u t circular cusp. A boss produced downward from the base of the cusp on both the anterior and posterior margins encloses a sma]JL basal cavity.

The o u te r-la te ra l process i s longer and i s produced doimward to a greater extent than the inner lateral process, and bears as many as 9 short, discrete, peg-Hke denticles that are circular in cross-section. The inner-lateral process may have 6 node-like denticles that are shorter than those of the outer-lateral process. Undersides of the processes are strongly inverted and this feature is one of specific significance.

The microcoelodiform element (Pl, 1, figs. 17, 19; Text-fig. BO-D) is similar in many features to the erismodiform element. The cusp is 74

Text-fig. 8A-I. Curtognathus robustus (Branson and Mehl) (A, B) Line drawings of the erismodiform element, (C, E) the microcoelodiform element, (D) the cardiodelliform element, (F, H) the cardiodelliform element with a denticulate posterior process, (G) the curtognathiform element, and (I) the trucherog­ nathiform element. 75 short, stout, almost circular in cross-section; and a prominent boss is produced doimward from th e an terio r margin of th e base. The posterior and lateral processes bear short, peg-like, widely separated denticles and have the characteristic inverted bases A small basal cavity or pit is present beneath the cusp.

The cardiodelliform element (Pl, 2, figs, 3^» 3^; Text-fig, 8 d ) is identical to the one described as Cardiodus robustus by Branson and Mehl (19^3). I t is nearly symmetrical, arroi-r-shaped in superior or inferior view, with very short, node-like denticles and an inverted base that shows the laminar groirth pattern.

Another cardiodelliform element (Pl, 1, fig, 15; Text-fig, 8F, 8H) has a denticulate posterior process. This element is asymmetric, but has the same type of denticulation and the inverted base that charac­ terizes other elements of the apparatus of this species.

The curtognathiform element (Pl, 1, fig, 13; Text-fig, 8G) is a symmetrical, arched bar with 9 short, discrete denticles in most specimens and an inverted base displaying th e laminar groi-rth p attern .

The trucherognathiform element (Pl, 1, fig, 18; Text-fig, 81) is a sinuous bar \d.th indistinct node-like denticles and an inverted base.

All elements of this species are dark broim to black, opaque, and have a highly lustrous surface. Internal features cannot be seen.

Discussion, —The number of elements in the author*s collection suggests that the skeletal apparatus included 4 erismodiform, 4 dicho- gnathiforra, 6 trucherognathiform and curtognathiform elements combined, and 2 cardiodelliform elements. 76

Occurrence. —Curtognathus robustus is represented in the Lebanon

Limestone, Rutherford County, Tennessee; in the upper half of the Can^j

Nelson Limestone, Jessamine and Mason Counties, Kentucky; in the Gull

River Formation of the subsurface of Richland County, Ohio; in the

Pamelia and Lornrille of Le:d.s County, New York; in the Glenbumie Shale

Member of the •7aterta%n Limestone of Ontario; in th e Shadow Lake, Gull

River and Loizer Bobcaygeon Formations a t Coboconk, Ontario; in the

Basal Beds, Sxdft Current, Cloche Island and Unnamed Beds of Grand Cloche

Islands; in the m f f l in . Grand Detour and Nachusa Formations of Batchtot-m

Quarry, Illinois, Branson and Mehl (1943) reported elements of the species from the lower Bromide of Oklahom, and Schopf (I 966) illustrated similar forms from Wilderness strata in Nei-r York,

Repository,—î'îicropaleontological collections, the Ohio State

University,

Figured Hypotypes,—OSU 29624-29629

CURTOGNTiTHUS TÏPÜS Branson and Mehl, 1933

Pl, 1, figs, 16, 20 - 26; Text-fig, 9A-K,

Cardiodus arcuatus BR'iNSON AND î-iSHL, 1933, p. 82, Pl, 5, fig . I 6; BRiiNSON AND IffiHL, 1943, p, 382, P l, 64, fig , 48; BPAN30N, 1944, p, 69, P l. 10 , fig , 29,

cardiodus bifidus BRANSON AND MEHL, 1933, p. 82, Pl, 5, fig . 9; BRANSON, 1944, p, 69, Pl. 10, fig, 15.

Cardiodus delicatus BRANSON AND MEHL, 1933, p. 82, P l, 6, fig , 14,

Cardiodus densus BRANSON AND I-EHL, 1933, p. 81, Pl, 5, fig . 15? BRANS® AND MEHL, 1943, p. 385, P l. 64, fig , 21; BR.AN30N, 1944, p, 69, P l, 10 , f ig , 28, Cardiodus dim nutivus BENSON AND 1-IEHL, 1933, P. 83, Pl. 6, fig. 15; ÏOÜNGCSJIST and CULLISON, 1946, p. 580 , 581, Pl. 89, fig. 11.

Cardiodus divaricatus BPAN30N AND MBHL, 1933, P. 82- 83, P l. 6, fig . I 6.

Cardiodus divisus BRANSON AND MEHL, 1933, p. 83, 84, Pl. 5, fig. 10; BRfiNSQN, 1944, p . 69, Pl. 10, fig. 16. cardiodus tumidus BlViNSGN AND MEHL, 1933, p. 81, Pl. 6, fig. 19, Pl. 7, f ig . 2; BRANSON, 1944, p. 69, Pl. 10, figs. 5, 21-23.

Cardiodus vmiformis BRANSON AND ICHL, 1933, p. 83, Pl. 5, fig. 11, Pl. 6, f ig . 13; BRANSON, 1944, p. 69, Pl. 10, figs. 9, 17.

Cardiodus? distortus BRANSON AND MEHL, 1933, p, 108, Pl. 8, fig. 11; BRANSON, 1944, p. 79, Pl. 11, fig. 20.

Curtognathus typa BRANSON AND MEHL, 1933, p. 87, P l. 5, f ig . 28; Bj^ANSON, p . 69, Pl. 10, fig. 50; HASS, 1962, p. 53, fig. 32-3; lindstrom, 1964, p. 145, fig. 49g; ANDRS'fS, 1967, p. 887 , 888, Pl. II 3, fig s . 4, 21; P l. 114, fig . 22.

Curtognathus calyculoides BRANSON AND MEHL, 1933, p. 88, P l. 5, fig. 18, P l. 7, fig . 19; BR.N30N, 1944, p. 69, Pl. 10, figs. 34, 39; Sl'EET, 1955, p. 249, P l. 29, fig . 21.

Curtognathus coronata BRANSON AND I-SHL, 1933, p. 88, Pl. 5, fig. 26; BRANSON and IffiHL, 1943, p. 384, P l. 64, fig . 4?; BRANSON, 1944, p . 69, P l. 10, fig . 45; BR/iNSON AND MEHL, 1944, in SHEffiR AND SHROCK, p . 239, P l. 93, fig . 15.

Curtognathus UrAtaris BRANSON AND îffiHL, 1933, P. 88, Pl. 5, figs. 17, 23 , 25; BRANSON AND MEHL, 1943, p. 384, 386, Pl. 64, figs. 20 , 49; BRANSON, 1944, p . 69, P l. 10, fig s . 30, 42, 44; SNEET, 1955, p. 2'f9, Pl. 29, f ig . 16; -Æ3ER3, I 966, p . 63, P l. 4 , f ig . 3; ANDREEVS, 1967, p. 888, Pl. 114, fig. 5.

Curtognathus pectinella BRANSON AND MEHL, 1933, p. 89, Pl. 5, fig. 27.

Curtognathus ueculiaris BRANSON AND MEHL, 1933, p. 89, Pl. 5, figs. 20, 22; BRANSON, 1944, p. 69, Pl. 10, figs. 36, 41.

Curtognathus rustica BRANSON AND MEHL, 1933, p. 105, Pl. 8, fig. I 6; BRvNSON, 1944, p. 79, Pl. 11, fig. 27.

Curtognathus tenuis BRANSON AND MEHL, 1933, P. 105, Pl. 8, fig. 13; BRANSON, 1944, p. 79, Pl. 11, fig. 22. ■ Cürtognathus varians BîVvNSON AND MEHL, 1933» P* 89, P l. 5» f ig s . 19» 21, 24; BRTvNSON, 1944, p. 69, Pl. 10, figs. 35, 40, 43; MOSKi\LEMO, 1971» p. 63, Pl. 11, figs, ?, 8.

Hlcrocoelodus expansus BPAK30N AND MSHL, 1933» P» 93» P l. 6, f ig . ?; P l. 7, fig . lé ; STAUFFER, 1935» p. 145» 146, P l. 12, f ig s . 10, 15; FURNISH, BARRfvGY, AND ICCLLER, 1936, p. 1334, Pl. 1, fig s . 11, 13; BRANSON, 1944, p. 53» 67, P l. 8, ügs. 26, 27; p. 69, 71, Pl. 10, f ig . 33; YOUNGQÜIST AND CULLISON, 1946, p,. 533; PAY, 1952, p. I 3O; y.ÆET, 1955» p. 243, 244, Pl. 27, f ig s . 3» 19. Polycaulodus abortivus BR/^NSON AND MBHL, 1933, p. IO 6, 107» P l. 8, f ig . 29; Ba\N30N,“ï ^ , p. 82, P l. 11, f ig . 52.

Polycaulodus bidentatus BRi'iNSON AND I-EHL, 1933» P. IO 6, Pl, 8 , f ig s . 1-3; BRANSON AND MEHL, 1943» p. 382, 333, P l. 64, fig s . 15» 29; BRANSON, 19#» p. 82, Pl. 11, figs. 4-6; S-/SST, 1955» p. 250, Pl. 28, f ig . 5; liEBERS, I 966, p. 68. Pl. 6, fig. 10; AND.W//S, I 967» p . 897» 898, Pl. 112, figs. 2, 8, 15; MOSDILEMO, 1971» p. 82, Pl. 11, fig. 1.

Polycaulodus com ulatus BRANSON AND ÎEHL, 1933» P. IO 6, Pl. 8, figs, 9, 12; BRANSON, 1944, p. 82, P l. U , fig s . 18, 21; SIEET, 1955» p. 250, P l. 29, fig . 20; M0SKALF;îIK0, 1971» p. 82, 83, P l. 11, f ig . 4.

Polycaulodus in c lin a tu s BRANSON A® lEHL, 1933» p. 86, P l. 6, fig , 22; BRANSON AND I-EHL, 1944, in SHEER AND SHROCK, p. 239» P l. 93» f ig . 9; HASS, 1962, p. 64, fig. 41-4; ANDRE,VS, I 967» p. 893, P l. 113 » fig. 24, Pl. 114, fig. 11.

Polycaulodus normalis BRANSON AND }EHL, 1933» P. 86, 107, Pl. 6, figs. 20, 21, Pl. 8, fig. 18; BRANSON, 1944, p. 82, Pl. 11, fig. 29; MOSKALENKO, 1971» p. 83» P l. 11» f ig . 3.

Polycaulodus necularis BRANSON AND JEHL, 1933» p. 10?, P l. 8, fig . 4; BRANSON, 1944, p. 82, P l. 11, f ig . 7; S\EET, 1955» p. 250, 251, Pl. 28, fig. 15.

Polycaulodus trid en ta tu s BR^ANSON AND MSHL, 1933» p. IO 6, Pl. 8, figs. 5-7» 10; BRANSON AND >EHL, 1943, p. 382, Pl. 64, figs. 2?, 28; BRANSON, 1944, p. 82, P l. 11, fig s . 11-13» 25; SIEET, 1955» p . 251» P l. 28, fig . 2; MOSKfiLSNKO, 1971» p . 83» 84, Pl. 11, fig. 2.

Polycaulodus sp. BRfiNSON AND MEHL, 1933» p. I 6I, Pl. 8, fig. I 7.

Trucherognathus d isp ariH s BRANSON AND tSHL, 1933» p . 85, P l. 5» fig s . 3» 8; BRANSON, 1944, p. 72, Pl. 10, figs. 2, 3. Trachero?nathu 5 distorta BENSON AND IffiKL, 1933, p. 84, Pl. 5, fig. 1; BRfVNSON and Î-ÎEHL, 1943, p . 385, P l, 64, fig s. 30, 33; BRANSON, 1944, p . 72, P l. 10, fig . 1; BR=\N30N AND I®HL, 1944, in SHDIER and SHROCK, p„ 239, Pl. 93, figs. 2, 3; HASS, 1962, p. 46, fig. 24-4; UNDSTRQH, 1964, p. 145, fig . 94f; ANDHS'-ZS, I 967, p . 900, Pl. 112, fig. 20, Pl. 113 , figs. 10, 25.

Trucheroenathus eouidentata BRfiNSON AND IGHL, 1933, P* 84, 85, Pl. 5, f ig . 4; BRINSON, 1944'; p. 72, P l. 10 , f ig . 7.

Trucheroenathus expansa BBfiNSON AND I-EHL, 1933, p. 85, Pl. 5, fig . 5; BRINSON, 1944, p. 72, P l. 10 , fig . 8.

Trucherognathus irregularis BRANSON AND LEHL, 1933, 104, 105, Pl. 8, fig. 15; BRANSON and MSHL, 1943, p. 334, 385, Pi. 64, figs. 3I, 32; BPANSON, 1944, p. 82, Pl. 11, fig. 24.

Trucherognathus parallels BRANSON AND MEHL, 1933, t>. 105, P l. 8, fig . 14; BRANSON, 1944, p. 82, Pl. 11, figs. 2, 3.

Trucherognathus sinuosa BRANSON AND ÎEHL, 1933, p. 84, Pl. 6, fig. 10; GRAVES AND 3LIIS0N, 1941, p. 5, P l. 2 , fig . 3.

Trucherognathus sp. BRiNSON AND îEHL, 1933, p. 157, Pl. 5, fig. 7; BRfiNSON, 1944, p . 71, Pl. 10, fig. 10. mcrocoelodus obliguus STAUFFER. 1935b, p. 603, Pl. 73, figs. 53, 56.

Polycaulodus chatfieldensis STAUFFER, 1935b, p. 613, 6l4, Pl. 71, fig. 44.

Microcoelodus c f. exoansus FURICSH, BARRAGY AND MILLER, 1936, P l. 1, f ig s . 11, 13 .

Cardiodus abbrevlatus BRANSON AND ^HL, 1943, p. 385, 386, Pl. 64, fig. 18.

Curtognathus cordlformis BRANSON AND MEHL, 1943, p. 386, Pl. 64, fig. I 9.

Curtognathus sp. BRANSON AlfD lEHL, 1943, p. 386, Pl, 64, fig. 22.

Cardiodella tum dus BRANSON AND MEHL, 1944, in SEDER A^TD SHROCK, p. g39, Pl. 93,’figs. 17, 18; HiASS, I 962, p. 56, fig . 34-2a, 2b; UNDSTROM, 1964, p. 145, fig. 49h; ANDREIZS, I 967, p. 886, 887, Pl. 112, fig, 12, Pl. 114, figs. 1, 2, 6.

Polycaulodus sp, BRANSON, 1944, p. 80, Pl. 11, fig. 28.

Polycaulodus su. BRANSON AND LEHL, 1944, in SEDER AND SHROCK, p. 239, Pl. 93, fig. 4. 80

Polycaulodus sp. YOÜNC-QUIST km COIIISON, 1946, p. 539, Pl. 89, fig, 13.

Cardiodella sp. SCHOP?, I 966, P l. 6, fig s . 15, 18.

Curtognathus chatfieldensis (Stauffer). 'WSBSR3, I 966, p . 63, Pl. 4, fig. 4.

Curtognathus? sp. SCHOP?, I 966, P l. 6, fîgs. 2, 3, ?, 17, 22.

Erismodus? sp. SCHOPF, 1966, Pl, 6, fig . 10.

Pblvcaulodus sp. SCHOPF, I 966, P l. 6, figs. 5, 6.

Trucherognathus ? sp. SCHOPF, I 966, P l, 6, f ig . 11.

Erismodus? expansus (Branson and Mehl) ANDRS’/S, 196?, p. 895, Pl. 114, f ig s . 16, 23 .

Curtognathus cristatus MOSKALENKO, 1971, P. 6I, Pl. 11, fig. 10.

Curtognathus elegans MOSK/».LSNKG, 1971, p. 6I, 62, Pl. 11, fig. 5.

Curtognathus subtilis MOSK/iLSiKO, 1971, p. 62, Pl. U , fig, 6.

Curtognathus sp. MOSKALENKO, 1971, p. 63, P l. 11, f ig . 9.

Elements of the form-genera Cardiodella. Curtognathus, Polycaulodus and Trucherognathus occur in large numbers in this collection, where they are associated T-dth elements of the form-species Idcrocoelodus expansus.

These 2036 elements, which make up 7.46 percent of the collections, are characterized by long, slender, widely separated dentidles and a virtually flat base, AH of them are coirpatible in size and are dazk brovm in color; only a few are transparent. The author does not hesitate in regarding these elements as parts of the skeletal apparatus of a single species, Curtognathus typus Branson and Mehl.

The microcoelodiform element (Pl. 1, figs. 23, 26; Text-fig. 93-C), described by Branson and Mehl (1933) as Microcoelodus exoansus. does not closely resemble any other Microcoelodus. The element is asymmetrical. 81 and has long slender denticles and a small basal cavity or pit that does not penetrate the cusp. The denticles are circular in transverse section and are separated from one another by distances greater than their diam eters. The cusp is slig h tly reclined and in a few specimens bears two la te r a l costae.

One of the polycaulodif orm elements of Curtomathus tvpus (Pl, 1, f ig , 16; Text-fig, 9A, 9D) is indistinguishable from elements of the form species Polycaulodus bidentatus Branson and Mehl, The base is flat, ovate in shape, and in some specimens bears a tiny central pit surrounded by well-preserved groirth lines. The tifo reclined denticles are long, slender, circular in section, and divergent,

A second type of polycaulodif orm element (Pl, 1, fig, 25; Text-figs,

9E, 95)» identical with elements of the form-species P, tridentatus

Branson and Mehl, bears from 3 to 5 denticles. It is transitional with the first type of polycaulodif orm element described and with the trucherognathiform element described in a subsequent paragraph.

Some specimens of this element vdth a short denticle posterior to the cusp might be regarded as an element of the form-genus Trucherognathus,

The base of this polycaulodiform element is like that of the first one described and like that of the trucherognathiform element as well.

Elements in my collection identical vdth those described as for- species Curtognathus chatfieldensis by Stauffer (1935)» and as C, typa and C, pectinella by Branson and Mehl (1933) are morphologically inter- gradational and are referred to Curtognathus tyous, as are elements of th e form-species C, liïïp.taris Branson and Mehl (1933), which is Text-fig. 9A-K. Curtognathus typus Branson and Mehl. (A, D) Posterior view of an element of the form-species Polycaulodus bidentatus, (B,C) posterior view of the micro­ coelodiform element, (E, G) lateral view of an element of the form-species Polycaulodus tridentatus, (F) posterior view of a curtognathiform element, (H, I) posterior view of a cardio­ delliform element, (J,K) lateral view of a trucherognathiform e le m e n t.

84 transitional in form between the polycaulodiform and curtognathiform elements

The curtognathiform elements (Pl. 1, fig. 20; Texfc-fig. 9?) are arched bars vjith long dentioLes of circular section and a flat base that has a small pit at the center.

Specimens identical to elements of the form-species Trucherognathus distorta Branson and Mehl (1933) (Pl. 1» fig. 24; Text-fig. 9Jj 9K) are long slightly sinuous bars Tilth long, transversely circular, discrete denticles, some of which arc deflected to one side, others to the opposite side. The base is flat to slightly convex in large specimens, and the edges of grorrth lamolae are well displayed.

Elements indistinguishable from typical representatives of the form-species Cardiodella turn!da (Branson and Mehl) are also common in my collection. These elements (Pl. 1, figs, 21, 22; Text-fig. 9H, 91) are arrai-shaped in superior view, slightly asymmetric, Tilth flat bases and long slender, transversely circulât, iddely spaced slightly reclined d e n tic le s.

The frequencies viith which elements of Curtognathus exoansus are represented in my collection (Table 1) suggest that the apparatus in the conodont included 2 microcoelodiform, 10 polycaulodiform, 4 trucherognathiform, 4 curtognathiform, and 8 cardiodelliform elements.

Occurrence.—Curtognathus tyous is represented in nearly every sarçle in every section studied. Elements of this species have also been reported from th e Dutchtown (Youngquist and CuUison, 19^p6), Joachim

(Branson and Mehl, 1933; Andrews, I 967), and Plattin (Branson and Mehl,

1933) Formations of Missouri; from the Glenwood of Minnesota (Stauffer, 1935b); ^Tebers, I 966); îrom Wildemess strata in New York (Schopf, I 966); from th e lor-rer Lexington of Kentucky and Ohio (Bergstrom and Sweet, 1966); from th e Harding Sandstone of Colorado (Sr-xeet, 1955)» from the McLish and Bromide Formations of Oklahoma (Branson and Mehl, 19^3)» from post-

Deadwood, pre-%Vhitewood Shales in the Black H ills of South Dakota

(Furnish, Barragy, and M iller, 1942); and from the Woods Holloix Shale of the Marathon Region, Texas (Graves and Ellison, 1941).

Repository.—Micropaleontological Collections, The Ohio State

U niversity. Figured specimens, OSU 29630-29635

Genus DISTACODUS Hinde, 1879

Machairodus PANDER, I 856, p, 22.

Distacodus HINDE, 1879, p. 357.

Type Species.—Machairodus incurvus PANDER, I 856

distacodus FALC/iTUS S tau ffe r, 1935

P l. 3; fig s . 4, 5.

Distacodus falcatus STAUFFER. 1935a, p. 142, Pl. 12, fig. I 6; STAUFFER 1935b,' p. 605, ^1 . 74, fig . 30; ETHINGTON, 1959, p. 275, Pl. 39, f ig . 9; BERGSTROM, I 962, p. 38, 39, Pl. 1, fig. 15; SCHOPF, I 966, p . 51, P- 5, f ig i 27; 'SEERS, 1966, p. 27, Pl. 3» fig. 4; BERGSTROM and Sl-JEST, I 966, p. 329, Pl. 35, figs. 10-13.

Panderodus robustus (Branson. Mehl. and Branson). PULSE Aîro SIVEET, i 960, p. 256, 257, P l. 35, fig . 5.

IScolopodus comufornis SERGEEVA, I 963, p. 93-95, Pl. 7, figs. 1-3.

Distacodus a f f , D. falcatus S tau ffe r. ETHINGTON AND SCHUMACHER, I 969, p7450, Pl. 67, f ig . 14. Two forms have been included here in Distacodus falcatus « one is the typical form of the species (Pl, 3, fig, 5) vdth lateral costae, on a simple reclined, laterally compressed cusp vdth a shallow basal cavity. The second form (Pl, 3» fig. 4), which is not common in this collection, is asymmetric, lacks costae, but has a keel on the a n te rio r margin and a sim ple, reclined cusp whose curvature begins nearer to the base than in the typical form.

The stratigraphie association, in this collection, of Acontiodus alveolaris and Distacodus falcatus suggests that these elements, may be conspecific and the species should be reviewed vdth this consideration in mind.

Occurrence, —The au th o r's collections contain a to ta l of 179 specimens assigned to Distacodus falcatus. These specimens indicate that the species ranges from the Pierce limestone to the top of the lower Carters Formation in the Central Basin of Tennessee, It is represented in the basal Middle Ordovician beds of the subsurface of

Richland County, Ohio, Specimens were recovered from the P la tte v ille ,

Decorah, and Galena Formations of Wisconsin and Iowa, and the species ranges from the Glenwood as high as the Dubuque Formations in Minnesota

(Webers, 1966), Specimens have been reported (Schopf, I 966) from the

Denmark and Cobourg "Formations" of New York and southern Ontario; and

Bergstrom and Sweet (I 966) report representatives of the species from the Lexington and Kope Formations of Ohio and Kentucky,

Repository, -~Mi c repaie ontological C ollections, The Ohio State

U niversity, Reference S lid e s, 70VL-3i 4, 7; 70VJ-2, 12; 65X2-3929, 393^, 3937 , 3951, 3953; 702A-996, 100?, 1039, 10^*8, 1057, 1067, 10?7, 1086, 1129; 70VH-3-9* Figured specimens, OSU 29636, 29637

Genus DREPANOISTODUS lindstrom , I 97I

Drepanoistodus LINDSTROM, 1971, p. 42.

Type Species. —d sto d u s forceps LINDSTROM, 1955.

DRE3AN0IST0DUS SUBERSCTUS (Branson and Mehl)

Pl. 1, figs, 6-8.

?Distacodus arcuatus STAUFFER, 1930, p. 123, Pl. 10, fig. 21; ST/iUFFER 1935, p. 258.

Distacodus suberectus BRANSON AND MEHL, 1933, p. I ll, Pl. 9, fig. 7.

Drepanodus suberectus (Branson and Mehl), BERGSTROM AND SV/EET, 1966, p . 330- 333, Pl. 35, figs. 22 - 27, (includes synonymy through I 966); OBERG, 1966, p. 137, 138, Pl. 16, fig. 1; WEYANT, I 968, p. 4?, P l. 2, f ig s . 11, 12; BRADSHAW, I 969, p. 1150, Pl. 135, fig. 7; ETHINGTON AND SCHU1#CHER, I969, p . 4 6 l, 462.

Drepanodus homocurvatus lindstrom . OBERG, I 966, p. 137, Pl. 15, fig. I 6; ANDRE'NS, 1967, p."889, Pl. 113, fig. I 6, Pl. 114, figs. 8, 15; SERPAGU, 1967, p. 38 , 39, P l. 15, fig s . 7&-7o; BARNES, I 967, p . 236; WEYANT, 1968, p. 46, 4?, Pl. 2, figs. 13, 14; BRADSHAW, 1969, p. 1150 , P l. 135, fig . 8; ETHINGTON AÎID SCHUMACHER, I 969, p . 461.

Q istodus in c lin a tu s Branson and Mehl. OBERG, I 966, p. 139, P l. 15, fig. 3; ANDREiNS, 19^77 pr895, Pl. H 4, fig. 10; BARÎŒS, I 967, p . 236; WEYANT, 1968, p. 53, P l. 2, f ig . 8; BRfiDSHAW, I 969, p . 1156, P l. 133, fig s . 11 - 13 .

Qistodus excelsus Stauffer. OBERG, I 966, p. 139, Pl. 15, fig. 2.

Drepanodus sp. BRADSHAW, I 969, p. 1150, Pl. 131, figs. 1, 2.

The specimens herein assigned to Drepanoistodus suberectus

(Branson and Mehl) represent a ubiquitous multielement species that has been referre d by previous authors to Drepanodus Pander, 18$6,

Lindstrom (1971), hoifsver, has recently established Drepanoistodus for species vdth similar skeletal apparatuses, and D, suberectus clearly belongs in that genus, rather than in Drepanodus, whose skeletal apparatus was probably somewhat d iffe re n t.

The collection at hand contains 298 representatives of the form- species Drepanodus suberectus. 3OI9 of D. homocurvatus. and 713 of

Qistodus in c lin a tu s . These 4030 elements c o n stitu te I 5.U percent of this Black River collection. Drepanoistodus is represented in every section sampled and in nearly every sample. Webers (I 966) and Bergstrom and Sweet (I 966) suggest ratios of 6 homocurvatus elements to 2 suberectus and 2 inclinatus elements, whereas Schopf (I 966) in d icates a probable ra tio of l6 ;2 ;4 . The co llections a t hand, as numerous as

Schopf*s and Weber's, but substantially smaller than Bergstrom and Sweet's, suggest a ratio of 20:2:4.

Repository.—Micropaleontological Collections, The Ohio State

U niversity. Figured Specimens, OSU 29638- 29640

Genus ERESMODÜS Branson and Mehl, 1933

Srismodus BENSON AND MEHL, 1933, p. 25.

Type Species.—Srismodus typus BRANSON AND MEHL, 1933*

Ihe genus Erismodus îjas erected by Branson and Mehl (1933) for fibrous elements from the Harding Sandstone of Colorado, which consist of arched bars with an apical cusp, a fe>r low rounded denticles on the 89 upper surface, and an excavated base containing a boss produced down­ ward on the a n te ro la te ra l n&rgin, A symmetry tra n sitio n e x ists between elements of the form-genera Erismodus. Microcoelodus, and

Ptiloconus (or Pteroconus) that have been collected from sainples upon which this study is based. These elements are therefore assigned, on the basis of priority, to Erismodus, Andre^-rs (196?), in a study of

Joachim conodonts and of Branson and Mehl’s 1933 types, concluded that these genera included components of sev eral closely re la te d form- transition series, A majority of the described form-species of these genera were then included in four species of Erismodus, From the material at hand, the author can see no reason for maintaining four species when the elements by which they are represented are all transitional in character. Therefore the generic concept of Erismodus is expanded to a multielement genus, which contains elements previously assigned to species of the form-genera Microcoelodus and Ptiloconus,

EBISMODJS 3/vDÏCéiNS (Hinde), 18?9.

PI, 1, fig. 5, PI. 3, figs,

Prioniodus radicans HINDS, 1879, p , 35Ô-357» P I, 15» fig s , 1-5.

Erismodus abbreviatus BRANSON AND MSHL, 1933, p. 25, PI, 1, figs, 8, 17; MCLAUGHUN, in BRANSON, 1 9 ^ , p. 53, 67, g l, 8, figs, 12-19; SÆBT, 1955, p. 233, PI. 28, fig, 10; HNDSTROM, 1964, p, 145, fig , 50b,

Erismodus? curvatus BRANSON AND MEHL, 1933, p. 26, PI, 1, fig , 18.

Erismodus digitstus BRANSON AND MEHL, 1933, P. 26, PI. 1, fig , 36; MCLAUGHUN, 1941, in BRrlNSON, 1944, p , 67, P I, 9, fig s , 27 , 28, Erismodus (?) dubius B3/iNS0N AND MEHL, 1933, p. 104, PI, 9, fig. 5, 6; BRi\NSON, 19#, p. 79, Pl. 11, figs. 9, 10.

Erismodus simplex BR/\NSON AND IffiHL, 1933, p. 26, Pl. 1, figs. 15, l 6; SWEET, 1955, p. 234, Pl. 29, fig. 19.

Erismodus? striatus BRANSON AND MEHL, 1933, p. 26, 2?, Pl. 1, fig. 26.

Erismodus radicans BRANSON AND MEHL, 1933, p. 156, ni. 12, fig. 14, 18, 19; SWEST, 1955, p. 233, 234, Pl. 29, figs. 22, 29; EASS, 1962, fig . 31-1.

Erismodus symmet^cus BRANSON AND MEHL, 1933, p. 104, Pl. 10, fig . 10; ANDRBi'fS, 1967, P .-892, 893, Pl. 112, figs. 4, 5, 13, I 6, 21, P l. 113 , fig. 7, Pl. 114, figs. 4, 18, 24; TffiEERS, I 966, p. 63, P l. 4, fig . 7.

Erismodus typus BRfiNSON AND MEHL, 1933, p. 25, Pl. 1, figs. 9, 11, 12; MCI/iUGHIIN, 1941, in BRANSON, 1944, p. 67, P l. 9, fig s . 29 , 30; SWEET, 1955, p. 234, P l. 27, f ig . 5, P l. 29, fig s . 7, 8; HASS, 1962, p. 53, fig . 32- 2 ; ANDREWS, I 967, p. 891, 892, P l. 112 , fig s . 9, 10, 11, 18; Pl. 114, fig. 21.

Microcoelodus abnormalis BRfvNSON AND MEHL, 1933, p. 90, P l. 6, fig . 9.

Microcoelodus alatus BR/iNSON AND >!EHL, 1933, p. 91, Pl. 6, fig s. 27 , 28, p. 160, Pl. 7, fig . 28.

Microcoelodus asymmetricus BRANSON AND MSHL, 1933, %). 91, P l. 7, fig s. 5, 10, 11, 14, 15; BRANSON AND MEHL, 1943, p. 383, 384, Pl. 64, figs. 37, 39, 41, 46; BRW^SON, 1944, p. 69, P l. 10, f ig s . I 3, 14, 24, 25, 31 , 32; EÆET, 1955, p. 243, P l. 28, f i s . 4; WEBERS, I 966, p. 65, Pl. 4, fig. 10; HOSKfiLEMO, 1971, p. 71, Pl. 12, figs. 1, 2.

Microcoelodus brevibrachiatus BRANSON AND MEHL, 1933, u. 91, 92, P l. 7, figs. 3, 27; BRANSON, 1944, p. 69, P l. 10, fig . 6; VEBERS, I 966, p. 65, P l. 5, f ig . 10 .

Microcoelodus breviconus BRANSON AND IfflHL, 1933, p. 93, P l. 6, fig . 29.

Microcoelodus duodentatus BRANSON AND MEHL, 1933, p. 92, Pl. 7, fi

Microcoelodus ma?nicomis BRANSON AND MSHL, 1933, p. 93, 94, Pl. 7, fig s . 13 , 17; BRANSON, 1944, p. 69, P l. 10, fig s . 27 , 37; S^.SST, 1955, p. 244, Pl. 29, f ig . 26.

Microcoelodus minutidentatuô BRANSON AND MEHL, 1933, p. 94, Pl. 7, fig s . 8, 9; BR'iNSON AND MSHL, 1943, p. 384, P l. 64, f ig . 5O; BRiNSON, 194if, p. 69, P l. 10, fig s . 19, 20. 91

Microcoelodus siitiplex BENSON AND I®HL, 1933, p. 94, 95, Pl. 6, fig s . 30, P l. 7, f ig . 23; BRiNSON, 1944, p. 69, Pl. 10, figs. 48, 54; ff/ffiET, 1955, p. 244, Pl. 29, fig . 5.

Microcoelodus symietricus BRiNSON AND MEHL, 1933, p. 95, Pl. 7, fig. 21; BRiNSON, 1944, p7^. Pl. 10 , fig . 47.

Microcoelodus typus BR/iNSON AND MEHL, 1933, p. 90, P l. 6, fig s . 3I, 32; BRiNSON AND MEHL, 1943, p. 383-385, Pl. 64, figs. 12, 36, 54- 56; BRiNSON AND MEHL, in SHIMER AND SHROCK, 1944, p. 241, P l. 93, fig . 70; YOÜNGQUIST AND OJLLISON, 194^, p. 585, P l. 90, fig . 7; HASS, 1962, p. 45, fig. 23-2; UNDSTRŒ!, 1964, p. 145, fig. 50a.

Microcoelodus unibrachiatus BRfiNSON AND MEHL, 1933, p. 95, Pl. 6, f ig . 23.

Microcoelodus unicornis BRfiNSON AND MEHL, 1933, p. I 6O, Pl. 7, figs. 20, 24, 25; /iMSDEN AND i-ULLER, 1942, p. 303, P l. 41, fig . 5; BRil^SON, 1944, p. 69, Pl. 10, figs. 46, 52, 53; Sl-BST, 1955, p. 244, P l. 28, fig . 21; WBBERS, I 966, p. 65, Pl. 4, fig. 6.

Microcoelodus unilateralis BRiNSON AND MSPIL, 1933, p. 96, Pl. 7, fig. 4; BRiNSON, 1944, p. 69, P l. 10, fig . 12.

Microcoelodus sp. BRiNSON AND MEHL, 1933, p. I 60, P l. 7, fig s . 6, 12, 22, 26, 29; BRiNSON, 1944, p. 7I, Pl. 10, figs. 26, 48, 54.

Pteroconus comoressus BRiNSON AND MEHL, 1933, p. 111, 112, I 63, P l. 8, fig . 31; BRiNSON, 1944, p. 57, 82, P l. 11, fig . I 7.

Pteroconus gracilis BRiNSON AND MEHL, 1933, p. U l, Pl. 8, figs. 28, 30, 32 , 35; STAUFFER, 1935, p. 617, P l. 75, fig . l ; /iMSDSN AND MILLER, 1942, p. 303, P l. 41, fig . 18; BRiNSON /iND lEHL, 1944, in SHIMER AND SHROCK, p. 241, P l. 93, fig . 69; BRiNSON, 1944, p. 80-82, Pl. 11, figs. 51, 53, 58, 64; POLLiCK, 1951, p. 36, 37, Pl. 6, fig. 12.

Pteroconus reversus BRiNSON AND ÎEHL, 1933, p. 99, Pl. 7, fig. 1; BRiNSON, 1944, p. 72, Pl. 10, fig. 4.

Pteroconus robustus FURNISH, BiRRiGY /iND MILLER, 1936, p. 1334, P l. 2, f ig . H .

Pteroconus sp. FURNISH, EiRRi&Y AND MILLER, 1936, p. 1334, P l. 2, fig . 6.

Erismodus sp. iiMSDEN AND MILLER, 1942, Pl. 41, fig . 17.

Erismodus? sp. BRiNSON AND MEHL, 1943, p. 380 , 385, P l. 63, figs. 1, 10, Pl. 64, fig. 17.

Microcoelodus inomatus BRiNSON AND MEHL, 1943, p. 384, Pl. 64, fig. 45. Microcoelodus interaiedius BR/vNSOM AND IffiHL, 19^3, p, 38^, P l. 64, fig s. 38, 40, 53; ÏCütîGQUIST AND CULLISON, 1946, p. 583 , 584, P l. 90, f ig . 6.

mcrocoelodus? sp. BRiiNSON AND MEHL, 1943, p. 384, P l. 64, fig. 44.

Erismodus n. sp. MCLAUGHEIN, in BRANSON, 1 9 # , p. 53, 70, Pl. 8, fig s . 22 , 23, Pl. 9, figs. 23- 26.

Eidsmodus s p ., BRfiNSON AND MEHL, in SHIMER AND SHROCK, 1944, p . 237, Pl. 93, fig. 14.

Microcoelodus c f. Aobius Md/vüGHIIN, in BRfvNSON, 1944, p . 67, P l. 8, fig s . 28, 29.

Erismodus dutchtorensis YOÜNGQUIST AND OJLLISON, 1946, p. 582, P l. 90, fig . 9.

Erismodus n. sp. YOÜNGQUIST AND CÜLUSON, 1 9 # , p. 582, 583, Pl. 90, figs. 3, 4.

Microcoelodus cuspus YOÜNGQUIST AND CULLISON, 1946, p. 583, P l. 89, figs. 20, 22.

Microcoelodus lobosus YOÜNGQUIST AND OJLLISON, 1946, p. 584, P l. 89, fig . 6.

Microcoelodus machaerodus YOÜNGQUIST AND CULLISON, 1946, p. 590, P l. 90, fig . 5.

tS-crocoelodus m issourienesis YOÜNGQUIST AND CÜLIZSON, 1 9 # , p. 584, 585, Pl. 89, fig. 21.

t&crocoelodus nodosus YOÜNGOÜIST AND CULLISON, 1 9 # , p . 585, P l. 89, f ig . 5.

Microcoelodus spicatus YCÜNGQÜIST AND CÜLIISON, 1 9 # , p. 535, Pl. 89, fig . 16.

Microcoelodus c f. M. unicom is YOÜNGQUIST AND CULLISON, 1 9 # , p. 585, 586, Pl. 89, fig. 2.

Microcoelodus sp. YOÜNGQUIST AND CULLISON, 1946, p. 586, Pl. 89, fig . 10.

Microcoelodus n . sp. YCÜNGQÜIST AND CÜLIISON, 1 9 # , p. 586, P l. 89, fig . 15.

Erismodus radicans (Hinde) y.-EET, 1955, p. 233, 234, Pl. 29, fig. 22, 29. 93

Ptiloconus comoressus (Branson and Mehl) S.ffiET, 1955» p. 246, P l. 28, fig. 1; ^ÆBERS, 1966, p. ?0, Pl. 5, fig. 9.

Ptiloconus g ra c ilis (Branson and Mehl) ff/JEET, 1955» p. 246, P l. 28, fig s . 6, 20; mss, 1962, p. 45, fig. 2>4; OBERG, I 966, p. 141, P l. 16, figs. 2, 4; IVEBERS» 1966, p. ?0» Pl. 5» fig. 8; MOSKiVLBMO, 1971» p. 85» P l. 6, f ig . 5.

Erismodus incurvescens HARKIS, 1964, p. 173» 174» P l. 1 , f ig . 1; MCUKD» 1965» p. 19» Pl. 2, figs. 16, 22.

Erismodus asymmetricus (Branson and Mehl) ANDRS'/S, I 967» p. 893» 894, P l. 112 , fig s . 1 , 3» 6, 7» 14, 17; P l. 113 » fig. 1» Pl. 114, fig s . 7» 9» 13 .

Erismodus g ra c ilis (Branson and Mehl) ANDHE.-/S, I 967, p. 894, P l. 112, fig . 19. Erismodus sp. SCHOP?, I 966, P l. 6, fig . 13.

Microcoelodus sp. OBERG, I 966, p, 139, Pl. 16, fig. I 6,

Microcoelodus sp. SCHOPF, 1966, Pl. 6, f ig . 12.

Mcrocoelodus n. sp. C V/EBSRS, I 966, p. 66, P l. 4, f ig . 8.

Microcoelodus n, sp, B VffiBEKS, I 966, p, 66, Pl. 4, fig. 1.

Ptiloconus sp. SCHOPF, I 966, P l. 6, fig . 4.

Elements of the form-genera Erismodus. Microcoelodus and Ptiloconus. present in the collection at hand, are components of a form-transition series and represent the skeletal apparatus of a species of the e^anded genus Erismodus. There is no doubt as to the specific name for this biologic unit. Prioniodus radicans Hinde, I 879, has 54 years of very clear priority over any other name applied to elements of this species.

Andrews ( I 967)» who included P. radicans in Erismodus asymmetricus

(Branson and Mehl), ignored the rules of nomenclature. Additionally

Andrews subdivided Erismodus in to species on the b asis of symmetry and 94 applied specific names that best described the geometry of the element,

%e latter part of this procedure is not acceptable as it does not recognize priority. The author believes that if the skeletal apparatus includes a form-transition series, then every element in that form- tra n s itio n is a conçjonent of one biologic u n it and must carry the same name, Andrews in d icates th a t an "evolutionary morphological transition series" exists and that units of Erismodus became more asymmetric from Dutchtcnm to P la ttin tim e. The n ea rly 2500 elements at hand assigned to Erismodus radicans (Hinde) do not demonstrate any tendency toirard an asymmetrical form vdth time, as /uidrews suggested.

Elements of Erismodus radicans are characterized by similar size and curvature of the cusp, discrete, peg-like denticles on the processes, slightly excavated processes and by a basal cavity that is surrounded by a flared sheath and penetrates to the base of the cusp. Many of th e elements are amber in color and tran sp aren t,

Rhtios derived from frequencies recorded in this study suggest that the skeletal apparatus of Erismodus radicans included 2 micro- coelodiform, 2 eiismodiform, 12 ptiloconiform, 4 dichognathiform, and

4 eoligonodiniform elements.

Occurrence,—Specimens of Erismodus radicans are present in nearly every sample from every section studied except the Van Driest

Core, Sheboygan County, !fi.sconsin. Elements of the species are present in th e Dntchto^m and Joachim Formations of M issouri (Branson and Mehl, 1933;

Youngquist and C ullison, 1946; /«ndre^js, 19^7); th e Harding Sandstone of Colorado (Branson and Mehl, 1933; Sweet, 1955); th e Glenwood Shale of Minnesota (Stauffer, 1935; Webers, I 966) ; Wilderness s tr a ta of Nevr York

(Schopf, 1966); and the Winnipeg Formation of Manitoba (Oberg, I 966).

Moskalenko (1971) figures elements Identical to some of those of

E. radicans from the Middle Ordovician of Siberia,

Reoository. —MlcropaleontolodLcal Collections, The Ohio State

U niversity, Figured specimens OSU 29641-29645

Genus «OISTODUS» Pander, 856 I

Olstodus PANDER, I 856, p, 2?.

Type Species,—Olstodus lanceolatus PANDER, 18 56,

Olstodus vra.s established by Pander (18 56) as a form-genus, and a large number of form-species have been included in it by authors since I 856, Since 1955j hcn-:ever, a m ajority of conodont workers have followed lindstrom’s (1955) criteria for recognition of Olstodus,

That is , in conodont form-taxonomy, Olstodus includes only simple cones in which the upper edge of the base and the posterior margin of the cusp meet in an acute angle.

In 1964, lindstrom pointed out that specimens associated with those typical of the form-species Olstodus lanceolatus Pander in

Swedish Lower Ordovician rocks have "unusually little white matter" and form a symmetry-transition series that grades from roundyaform through cladognathodiform and cordylodiform elements to oulodiform structures. In short, as Lindstrom (1971) has recently emphasized, the concept of Olstodus is substantially different in multielement taxonoj>y than in form-taxonomy, and oistodiform elements ( i , e , , those 96

\d_th the shape characters of form-Oistodus) are parts of the skeletal

apparatuses of species referred to several multielement genera (Sweet

and Bergstrom, I 969, fig , 3 ),

Because the author is committed to multielement taxonomy, he

agrees that only species whose skeletal apparatuses are like that of

multielement Oistodus lanceolatus (lindstrom, 1964-, 1971) should

be referre d to Oistodus. Hoizever, there are s t i l l a number of

distinctive oistodiform elements that have been assigned names in

form-taxono:ny, but whose multielement a f f in itie s are unknown. Such a

form-species is 0, venustus Stauffer, 1935> which is represented by

several specimens in the collections at hand. If lindstrom's (1964, I 97I) interpretation of multielement Oistodus lanceolatus is correct, its

apparatus includes only fibrous elements, whereas those distinctive of

0, venustus Stauffer have abundant white matter. In addition, no other

types of elements seem to be consistent associates of the oistodiform

elements on which 0, venustus is based, or such elements are not

distinguishable from those of other species with multielemont apparatuses

formed of simple cones, possibly, the oistodiform elements of 0, venustus

■vjere the only types present in the skeletal apparatus of the species.

In any event, it is most unlikely that the sp^-cies represented by these

elements is an Oistodus,

Lindstrom (1971) suggests that elements identified as Oistodus venustus may have been coupled with drepanodiform elements and he assigns the species tentatively to Drepanoistodus, It is indeed possible that the apparatus of 0, venustus may have included drepanodiform

elements, but these may also be indistinguishable from those of 95

Xlzinasota (Stauffer, 1935; Webers, I 966) ; W ilderness s tr a t a of Nevr York

(Sdiopf, 1966); and theVttnnipeg Formation of Manitoba (Oberg, I 966) ,

Moskalenko (1971) figures elements identical to some of those of

£• TtLàlcans froa the Middle Ordovician of Siberia,

aepository.»-MLcropaleontological Collections, The Ohio State

IJhiversity, Figured specimens OSD 29641-29645

Genus "0I3T0DD5» Pander, I856

Oistodus PAKJ3R, I 856, p . 27.

Type Species .—Oistodus lanceolatus PAHDSR, 1856.

Oistodus was estab lish ed by Pander ( I 856) as a form-genus, and

a large number of form-species have been included in i t by authors

since ]^56. Since 1955, hovrever, a m ajority of conodont workers have

followedLindstrom* s (1955) criteria for recognition of Oistodus.

That is, in conodont form-taxono?y, Oistodus includes only simple cones

in which the upper edge of the base and the posterior margin of the

cusp m et in an acute angle.

In 196^, lindstrom pointed out that specimens associated with

those typical of the foim-species Oistodus lanceolatus Pander in

Swedish Lower Ordovician rocks have "unusually little white matter”

mod fors a sy»aetry-transition series that grades from roundyaform through üadognathodlform and cordylodiform elements to oulodiform

structures. In short, as lindstrom (1971) has recently eitphasized,

the concept of Oistodus is substantially different in multielement taxoooxy than in fora-taxonomy, and oistodiform elements (i.e ., those Xflth the shape characters of fona-Oistodus ) are parts of the skeletal apparatuses of species referred to several multielement genera (Sweet and Bergstrom, I 969, fig , 3 ),

Because th e author is committed to multielement taxonomy, he agrees that only species whose skeletal apparatuses are like that of multielement Oistodus lanceolatus (Lindstrom, 1964, 1971) should be referred to Oistodus. Horiever, th ere are s t i l l a number of distinctive oistodiform elements that have been assigned names in form-taxonomy, but whose multielement a f f in itie s are unknown. Such a form-species is 0, venustus Stau^ej^l935, which is represented by several specimens in the Lindstrom's (1964, 1971)

0, venustus Stauffer addition, no other types th e elements on which 0, v^^^^^^^^^^^^^^^H R em ents are not distinguishable from multielement apparatuses formed of sirrole cones. Possibly, the oistodiform elements of 0, venustus were the only types present iri the skeletal apparatus of the species.

In any event, it is most unlikely that the sp^.cies represented by these elements is an Oistodus,

Lindstrom (1971) suggests that elements identified as Olstodus venustus may have been coupled with drepanodiform elements and he assigns the species tentatively to Drepanoistodus. It is indeed possible. that the apparatus of 0, venustus may have included drepanodiform elements, but these may also be indistinguishable from those of 97

Drepanoistodus suberectus (Branson and Mehl), t'îith whieh 0, venustus is commonly associated. For exarqple, specimens of D, suberectus

occur in a l l but one of the 24 samples from which th e w rite r has

collected elements of 0, venustus; they are present in all 11 of the

samples from which Bergstrom and Sweet (1966) report 0, venustus:

and D, suberectus elements are also knmm from all but two of the

samples in which Webers (1966) id e n tifie d 0, venustus.

I t may ultimately be possible to determine if some of the

drepanodiform elements no;-; assigned to multielement Drepanoistodus

suberectus were a c tu ally components of th e apparatus of a species whose oistodiform elements are referred to the form-species

Oistodus venustus. Until it is possible to make such a determination,

hov-jever, the writer prefers to identify his specimens as "Oistodus"

venustus Stauffer, and encloses the generic name in quotation marks

to indicate that it is being used in a form-taxonomic sense,

"CŒSTODUS" VEI'TUSTOS S tauffer

PI, 2, fig, 16,

Oistodus yemi^jais. STAUFFER, 1935, p. 146, 159, P I. 12, fig , 12} BSRC-STaai AND SVJSST, 1966, p, 341, 342, P I, 35, fig s , 20, 21 (includes synonymy through 1966); VJIIUER, 1966, PI, 9, fig, 12; mTDiNT, 1968, p, 53, PI, 2, fig, 9; BRADSHiVW, I 969, p, 1158, P I, 134, figs. 4-7,

Only 75 elements of "Oistodus" venustus are present in the

writer’s collection. These elements represent a form-species that

has been adequately described in the literature, hence they are not

described here. Information gained from this study indicates that "0," 98 venustus ranges from the Pierce Limestone through the lower Carters

Formation of the Central Basin, Tennessee, and i t is represented in the b asal Gull River Formation in the Fan American Core, Richland County» of the Ohio subsurface. At Pikes Peak, Iowa, the species ranges through the Platteville and Decorah Formations. It has been reported from the

Lexington Limestone and Kope Formation of Kentucky and Ohio (Bergstrom and Sweet, 1966), from th e Trenton Group of New York and southern

Ontario (Schopf, I 966) , and from the Glenwood Shale to the Dubuque

Formation in Minnesota (Webers, I 966), The species is reported from limestones on Roved Island off the south west coast of Ellesmere Island in the Canadian A rctic (Weyant, 1963), from th e F t, Pena Formation of

Texas (Bradshaw, I 969), and from the Coburg "Formation" of Ontario

■(VHnder, I 966) , Longwell and Mound (I 967) report one specimen from the

Monocline Valley Formation of southern Nevada, however th is specimen is not figured.

Repository.—Micropaleontologicf-l Collections, The Ohio State

U niversity, Reference S lid es, 70VL-3, 4; 70VJ-7, 25, 33; 70VM-1-3;

65x 2- 3918, 3919, 3951; 70VR-2-14, Figured specimen, OSU 29646

Genus CÜLODUS Branson and Mehl, 1933

Oulodus BiVdîSON AND MSHL, 1933» p . H 6 ,

Gvrognathus STAUFFER, 1935» P« 1 ^ .

Type Species,—Oulodus mediocris BR/iNSON AND MEHL, 1933*

Oulodus was established as a form-genus by Branson and Mehl (1933) for elements consisting of an asymmetric arched and twisted denticulate 99

Text-fig. lOA-F. Oulodus serratus (Stauffer). (A) Lateral outline of the ozarkodiniform element, (B) lateral outline of the cyrtonlodlform element, (C) posterior outline of the trlchonode111form element, (D) posterior outline of the oulodiform element, (E) lateral outline of the cordylodiform element, and (F) posterior outline of the zygognathlform element. 100 bar with inequal denticulate lateral processes, Bergstrom and Sweet

(1966) recognized th a t Oulodus was a multielem ent genus in which ea rly species developed oulodiform and cordylodiform elements and later species added prioniodiniform elements. The composition of the skeletal apparatus was further expanded to include eoligonodiniform elements in some species of Oulodus (Kohut and Sweet, 1968), Discussions th a t the author has had viith Dr, Walter C, Sweet have led to the understanding of the apparatus of Oulodus serratus suggested here. The skeletal apparatus i s composed of 6 d iffe re n t forms of elem ents, 2 cordylodiform, an oulodiform, zygognathlform, trichonodelliform and ozarkodiniform element.

Further discussions -with Dr. Si-reet have led to the phylogeny suggested here (Text-fig, 11), That is, 0, mediocris is the oldest known species of Oulodus. though i t s range i s poorly knovjn. I t includes elements from the uppermost Plattin of Missouri described by Branson and llehl (1933) &s

Ozarkodina e g u ila te ra . Oulodus m ediocris, Cordylodus? sp u riu s. Trichoznathus recurva and Cordylodus concinnus. No zygognathlform element was described in their collections, 0, mediocris appears to be succeeded by 0, serratus, which ranges from the uppermost Platteville through the Decorah Formations . at Pikes Peak, Iowa, Oulodus serratus presumably gave rise to 0, oregonia. which ranges from the middle of the Lexington Limestone to the top of the

Richmond Group in Kentucky and Ohio (Bergstrom and Sweet, 1966j Kohut and Sweet, 1968), 0, oregonia appears to have developed a prioniodiniform element in place of the cyrtoniodiforra element of 0, serratus. Text-fig. 11. Suggested phylogeny of the genus Oulodus. Oulodus oregonia

Aphelognathus irregularis

It 4$

B ry a n to d ln a ? a b r u p ta

Oulodus serratus

Oulodus mediocris 103

Bryantodina? abrupta may have developed from an tmknown species of Oulodus by a reduction of a l l elements except the ozarkodiniform element and the development of a prioniodiniform element. The type specimen of abrupta is from th e JoachJju of Misso-oid and older than the oldest reported 0» mediocris. Aphelognathus may have arisen from an ancestral stock like B? abrupta by further reduction of the apparatus to the ozarkodiniform element,

OULODUS SERR/'vTUS (S tauffer)

PI. 1, figs. 12, 14; PI. 2, figs. 18, 23-28, 30, 32, 35.

T ex t-fig . lOA-F,

Cordylodus serratus STAUFFER, 1930, p. 124, PI. 10, fig. 7; STAUFFER AND THIEL, 1941; FAY, 1952, p. 83.

Prioniodus aoicalus STi'^UFFER, 1932, p. 259, PI. 40, fig. 3,

Prioniodus cristulus STAUFFER, 1932, p. 260, PI. 40, fig, 3; STAUFFER, 1935b, p. 616, PI. 73, figs. 57, 58 (not f ig . i?9); FAY, 1952, p . 170,

TPrioniodus siculatus STAUFFER. 1932, p. 26l, PI. 40, figs, 7, 12, 13.

Gyrognathus primus STAUFFER, 1935a, p. 144, PI. 12, figs. 8, 9. STAUFFER, 1935b, p. 606, PI. 71, figs. 25, 29-35, 38, 40, 42, 49, 51, P I. 72, fig . 24; FAY, 1952, p. 99.

Ozarkodina concinna (part) ST-AUFFSR, 1935a, PI. 148, fig. 41, 46, (not f ig . 45); ST.AUFFER, 1935b, p. 6I I , P I. 7I, figs 2, 4, 5, 8, 14, 17- 19, 22 , 26; FAY, 1952, p. 137; IVEBERS, I 966, pp. 35, 36, PI. 9, figs. 9-12.

Ozarkodina amorohina STAUFFER, 1935a, p. 148, PI. 10, fig. 5O; FAY, 1952, p . 137.

Ozarkodina reperta STfiUFFER. 1935a, P. 149, PI. 10, fig. 37; FAY, 1952, p. 138.

Ozarkodina robusta STiAUF’FER, 1935b, P. 612, PI. 71, figs. 1, 3, 6, 9- 13 , 15, 21; FAY, 1952, p. 138. Ozaricodina pauperata ST^'iUFFER, 1935b, p. 6 l l , P I, 71» fig s . l 6 , 24; PAY, 1952, p. 138.

Spbcordylodus elongatps STAUFFER, 1935a, pp. 153» 154» PI. 11» f ig . 33.

Subcordylodgg rectilineatus STAUFFER, 1935a, p. 154» PI. 11, figs. 30, 32.

Subcordylodus sinuatus (part) STAUFFER, 1935a, p. 154, PI. U , figs. 28» 37 (n o t fig s . 42, 45).

Trichoqnathus recurva (p a rt) BRINSON AND MEHL, STAUFFER, 1935a, p. 156, PI. 12, fig. 1 (not fig. 2); STAUFFER, 1935b, p. 619, PI. 71» figs, 20 , 27 , 39 » 41, 47, PI. 72, figs. 48, 56; (part) VffiBERS, 1966, pp. 48, 49, PI. 8, figs. 3, 5, (not figs, 6, 7).

Barbarodina grandis STAUFFER, 1935b, p. 603, PI. 73» figs. 6, 8; FAY, 1952, p. 66.

Barbarodina typicala STAUFFER. 1935b, p. 603, PI. 7 3 , figs. 4, 5; FAY, 1952, p. 66.

Gyrognathus planus STAUFFER, 1935b, p. 606, PI. 71, figs. 36, 48; FAY, 1952, p. 99.

Subcordylodus rectilineatus STAUFFER, 1935b, p. 6I 8, Pi. 73, figs. 7, 23 , 28, 29, 33, 39; fa y , 1952, p. 194.

Subcordylodus? inaegualis STAUFFER. 1935b, p. 618, PI. 73» figs. 2, 3, 17» 22 , 26; FAY, 1952, p. 194.

Trichognathus gyroides STAUFFER. 1935b, p. 619, P I. 71» fig s . 28, 43; FAY, 1952, p. 193.

Cordylodus grandis (Stauffer). 'ÆBER3. i 960, p. 26, PI. 8, f ig s . 11, 12 , 16.

Cordylodus serratus Stauffer. -VEBS35, I 966, p. 27, PI. 9» figs. 1-3» 5.

Trichonodella recurva (part) (Branson and Mehl). IJEBERS, 1966, p. 49, P I. 8, figs. 3, 5 (not figs. 6, 7).

The form-species Cordylodus serratus Stauffer (Pl, 1, fig. 14;

PI. 2, f ig . 27; T ex t-fig . 103), Oulodus primus (S tau ffer) (P l. 2, fig s .

23 » 32 , Text-fig. lOD), Cordylodus grandis (Stauffer) (Pl. 1, fig, 12;

Pl. 2, fig. 33; Text-fig. lOB), Zygognathus gyroides (Stauffer) (Pl, 2, 105 . fig s , 18, 26} Text-fig, IGF), Ozarkodina concinna Stauffer (Pl, 2, figs, 24, 25; Text-fig, IDA) and specimens assigned to Trichonodella recurva (Branson and Mehl) (P l, 2, f ig s , 28 , 30; T e x t-fig , IOC) are associated in Middle Ordovician rocks in some parts of the North

American M dcontinent, They have been reported rece n tly by Webers (I 966) and earlier by Stauffer (1935^) from the lîiddle Ordovician of southeast

Minnesota, They are represented in the vnûter*s collections from the

Decorah Formation of !'fi.sconsin and th e Quimbys M ill Formation of Batchtovm,

Illinois, but are well represented only in collections from the Decorah

Formation at Pikes Peak, lo^ja, vAiere 504 elements viere recovered,

A total of 5O8 elements assigned to 0, serratus account for 1.91 percent of the collection. All are the same size, the same color and have the same robust construction; except for the ozarkodiniform element, all have the same type of discrete, peg-like denticleis on the processes.

It is apparent to the author that these elements represent a single biologic u n it, Oulodus s e rra tu s (S ta u ffe r),

Oulodus serratus is restricted geographically to the central part of the North American Midcontinent and is knovm only from sections in the Mississippi River VaHey and eastern Wisconsin, The species is apparently a Midcontinent faunal element. In the Decorah Formation of northeast loi-ra and eastern Wisconsin, the lovrer lim it of the range of th e species coincides with th e lovrer range lim it o f Phragmodus undatus,

0, serratus is present in the highest sançle from the Quimbys Mill

Formation in Batchtown Quarry, southwestern Illinois, but P, undatus is not represented in this sagiple, Webers (1966) found that 0, serratus 106 ranges lower in the Minnesota section than does P. nndatns, and he also indicated that the upper lim it of 0, serratus is coincident vdth the upper lim it of the range of elements here assigned to Plectodina aculeata in southeast Minnesota, The same range-relationships exist betvreen 0. serratus, P, aculeata and P, undatus in the Pikes Peak sectio n in Iowa. In th e Decorah Formation o f Sheboygan County, ‘Vdsconsin, however, the single occurrence of 0, serratus is above the highest P, aculeata but beloif the lowest occurrence of elements of Plectodina fu rc a ta , v*ich marks th e base of Fauna 9 of Sweet and others (1971).

At Batchtotm, Illinois, the single occurrence of 0. serratus is within the range of P, aculeata. Thus in terns of associated species, the range of 0, se rratu s appears to be from beloij th e low est Phragmodus undatus to the level of the highest occurrence of Plectodina aculeata.

IVhere i t occurs 0. serratu s i s thus a usefu l index to Conodont Fauna 8

(Svreet and o th ers, 1971).

Reoository.—Mioropaleontological Collections, The Ohio State

U niversity. Reference S lid e s, 7lZfi-1109; 70VI-21; 70VH-9-14.

Figured Specimens, OSU ' 29647-29652

Genus PANDEHODUS Ethington, 1959

Panderodus ETHINGTON, 1959, p. 28^.

Type Species.—Paltodus uni costatus BRiiNSON AND MEHL, 1933.

PANDERODUS GRTiCELIS (Branson and Mehl)

Pl, 3, figs. 32, 33.

Paltodus gracilis BRiVNSON AND MEHL, 1933, p. 108, Pl, 8, figs, 20, 21, 107 panderodus gracilis (Branson and Mehl), BBRGSTBOM AND SIIEET» 19^6, p . 355-359» P l. 35» fig s . 1-6 (includes synonymy through p a rt of 1966); ÛHSRG, 1966, p. 140, Pl. 16, f ig . 3; andreTvIs, 1967» p. 896, P l. 113 » f ig . 9; BilHNES, 1967» p. 236: SBRPAGII» 1967, p. 57-59» P l. 23 » fig s . 3a-5c; VJBMT, 1968, p. 56» 57» P l. 5» fig s . 1» 2.

Panderodus comoressus (Branson’and Mehl), 0BER3, 1966, p. 140, Pl. 15» f ig . 8; ANDm-rs, 1967» p . 895, 896, P l. 113» f ig . 3; B/vRIES» 1967» p . 236; SERPAGIZ, 1967» p. 56» 57» Pl. 6, figs. 4a-5b; VffiïANT» 1968, p . 55» 56» Pl. 6, figs. 1, 2.

Panderodus intermedius (Branson and Mehl), OBERG » I 966, p. 140, Pl. 15» f ig . 17.

Panderodus fetûneri (Glenister), m m SS, 196?» p. 236; ViEriNT, 1968, Pl. 5, fig. 4. Panderodus arcuatus VfiLnder. l'7EY.\NT, I 968, p. 55» P l. 2, f ig . 9.

The author*s collection contains 1,925 elements of the form-species

Panderodus gracilis and 1,005 elements of the form-species Panderodus

comoressus. These 2,930 elements constitute 10.99 percent of the col­ lection and the 2:1 ratio of graciliform to compressifom elements is the same as the ratio suggested by Bergstrom and Sifeet (I 966) from their study of the conodonts from the Lexington limestone and Kope

Formations of Kentucky and Ohio. Webers (I 966), in a study of the

Middle and Upper Ordovician conodonts of Minnesota, listed nearly

3»000 elements assigned to P. gracilis and P. comoressus in a ratio of

4 :1.

panderodus gracilis is represented in the lo-rest sarples fr«n the

Murfreesboro Limestone of central Tennessee and at the base of the

exposed Camp Nelson Limestone of Kentucky, Conspecific elements are present in Chazyan and lower Black River s tr a ta in the subsurface of

Idchland County, Ohio, and in a sangle from the Cordnco Core, Mason 108

County, Kentucky, H 5 fe e t above th e reported top of the Lovrer

Ordovician Knox Dolomite, "Thus the Imrer lim it of the range of the species can be defined by th is study, w ithin Fauna 6 of Svreet and others (1971), belovr the base of the Phracrmodus lnf].exns "zone," The species ranges from th e Glemrood Shale through th e Maquoketa Formation in Minnesota and Iowa (G lenister, 1957? Ethington, 1959; Webers, 1966),

Representatives of the species are present from the Watertoim through the Denley Limestone of New York and southern Ontario (Schopf, I 966),

BergstrSm and Sweet ( I 966) report representatives from the Lexington

Limestone and Kope Formation from Kentucky and Ohio, Representatives of the species are present in Edenian strata (Sweet and others, 1959)» in Maysvillian strata (Kohut and Sweet, I 968), and in Üchmondian rocks (Pulse and Sweet, I 96O) of the Cincinnati Region, Elements of the species have been reported from the Deer Island Member of the Winnipeg

Formation of Manitoba (Oberg, I 966) , from the uppermost Joachim Dolomite of Missouri (Andrer-Ts, I 967), the Watertotm Limestone of the Ottawa

Valley (Bames, I 967), from Ashgillian strata of the Camic Alps

(Serpagli, I 967), and from Ordovician limestones on Roved Islan d on th e southwest coast of Ellesmere Island in the Canadian Arctic (Weyant, I 968),

Repository, —>acropaleontological C ollections, The Ohio S tate

University,

Figured Specimens. —OSU 29653, 29654. P/iNDBRODÜS PANDSBI (S tauffer)

Pl. 2, fig. 29

Paltodus uanderi STAUFFER, 1940, p. 427, Pl. 60, figs. 8,9.

Panderodus panderf. (Stauffer), BERGSTRŒÎ km S’.'JEST, 1966, p. 359-361, Pl. 35, figs, lA, 15, Text-fig. 11, (includes synonymy through part of 1966); OBERG, 1966, p. 140, l4 l, Pl. 15, fig. 1; B/iRNES, 1967, u. 236; ’ÆïTvNT, 1968, o. 58, P l. 5, f ig . 13; EIHINGTON AND SŒOÎ^fvCHER, 1969, p. 469, Pl. 69, f ig . 15.

Only seven representstives of this species are present in this

collection, aU from the Platteville and Decorah Fondations of loiva.

Panderodus oanderi is knor.?n from the Lexington Limestone and Kope

Fom ation of Kentucky and Ohio (Bergstrom and S^-ieet, I 966) , the Glenwood

Shale to th e Maquoketa Formation of Minnesota (Webers, I 966) , the

%ldemess and Bameveld strata of Neir York (Schopf, I 966) , the Bighorn

of Wyoming and the Stoney Mountain and Shammatta^za of Manitoba (Oberg,

1966).

Repository. —M ioropaleontological C ollections, The Ohio S tate

University. Reference slides, 70VK-5, 9, 10.

Figured Specimens .—OSU 29655

Genus PHRAGMODUS Branson and Mehl, 1933

Emend. Bergstrom and Street, I 966

Phragmodus BRANSON AND Î-EHL, 1933, p. 98.

Type Species.—Phragmodus primus BRfiKSQM AND MEHL, 1933.

Bergstrom and Svzeet (1966) have emended and discussed the m ultielem ent

genus Phragmodus. The apparatuses of th e four species of Phragmodus

represented in the rocks studied are illustrated in stratigraphie order Text-fig. 12A-N. Four species of Phragmodus shown in their strat­ igraphie arrangement. (A-D) Phragmodus undatus Branson and Mehl, (E-G) Phragmodus cognitus Stauffer, (H-J) Phragmodus inflexus Stauffer, (K-N) Phragmodus tortus Sweet, ms. I l l Texb-fig, 12.

PHR\GMOrOS COGMTÜS S tau ffe r

P I. 2, f ig . 7-9, Texb-fig. 12E-G.

Phragmodus copnitus (p a rt) STAUFFER, 1935^, P« 150, 151, P I. H , fig s . 13^, 14 (not figs. 12 , 18, 31, 41); STAUFFER, 1935b, p. 613, PI. 72, f ig s . 27 , 28 , 33-37, 39-45, 50; FAY, 1952, p. 146; mEBBS, 1966, p. 41, PI. 11, figs. 1-3, 5, 6.

Ck'rtonlo dus coraplicatus STAUFFER, 1935^, p. 140, P I, 11, f ig s . 44, 46, 48-51; STAUFFER, 1935b, p. 604, PI. 73, figs. 9, 11-13, 15, I 6, 18- 20 , 25, 27, 32 , 38, 41, 42, 47.

Cvrboniodus apicalis STAUFFER, 1935b, p. 604, PI. 73, figs. 1, 10, 43 , 45.

Cordylodas fle;niosus (Branson and Mehl), T/EBERS, I 966, p. 25, 26, P I. 8, f ig . 8.

The d escription of Phra^iaodus cognitus S tau ffe r given by Webers (I 966) is emended here to include cyrtoniodiform elements that are similar to those referred by many authors to Cyrtoniodus comolioatus Stauffer,

The c o llectio n a t hand contains 237 elements of the form-species

Phragmodus cognitus « IO 3 dichognathiform elements, and 102 cyrtoniodiform elements. Ratios derived from these figures suggests that the skeletal apparatus included 4 phragraodiform elements and 2 each of the dichognathiform and cyrtoniodiform elements. These 442 elements assigned to this species represent 1,66 percent of the collection.

Occurrence. —Phragmodus cognitus is present in the basal sample of the Decorah Formation of Pikes Peak, and in the Platteville

Formation of central-eastern Wisconsin, I t ranges from the upper beds of the Glenwood Shale into the lower part of the Decorah Formation of southeast Minnesota (S tau ffer, 1935&, 1935b; Webers, I 966) , This restricted geographic occurrence indicates that P, cognitus is an element of the Midcontinent fauna. Stratigraphically it occurs in the 113

uppermost beds of the Phragmodus inflexus "zone" and ranges into

strata characterized by Conodont Fauna 8 (Sweet and others, 1971).

Repository.—M icropaleontological Collections, The Ohio State

University. Reference Slides 70VH-9; 70ZA-1129, 1151, 1175.

Figured specimens.—0SU29656-29658

PHRAGMODUS INFLEXUS S ta u f f e r

PI. 2, figs. 11-14, 17; Text-fig. 12I-J.

Phragmodus inflexus (part) STAUFFER, 1935a, p. 151, P i. 11, figs. 9, 16, 20, 25, 26 (not figs. 15, 17, 19, 21, 22, 34); FAY, 1952, p . 146; WEBERS, 1966, p. 40, 41, Pi. 3, fig. 8; P i . 8, f i g s . 1 , 2 , 4 .

C y rto n io d u s c o m p lic a tu s STAUFFER, 1935a, p . 140, P i . 11, f i g s . 4 4 , 4 6 , 4 8 -5 1 .

D ich o g n a th u s p e c u l i a r i s STAUFFER. 1935a, p . 141, P i . 11, f i g s . 1, 4 , 6 , 11; FAY, 1952, p . 86.

D ich o g n a th u s ty p ic u s ( p a r t ) STAUFFER, 19 3 5 a, p . 141, P I . 11, f i g s . 2 , 3 , 5 , 8 (n o t f i g . 1 0 ); FAY, 1952, p . 86;ANDREWS, 1967, p . 8 8 9 , PI. 114, fig. 12.

Phragm odus s i n g u l a r i s STAUFFER, 1935a, p . 151, P i . 11, f i g s . 2 3 , 2 4 , 3 5 , 36; FAY, 1952, p . 146.

S u b co rd y lo d u s e lo n g a tu s STAUFFER, 1935a, p . 153, 1 54, P i . 1 1 , f i g s . 33 ;

S u b co rd y lo d u s s in u a tu s STAUFFER. 1 935a, p . 154, P i . 11, f i g s . 2 8 , 3 7 , 4 2 , 4 5 ; FAY, 1952, p . 194.

Cyrtoniodus flexuosus (Branson and M ehl), BERGSTROM AND SWEET, 1966, p. 324-327, PI. 32, figs. 9-11 (synonymy through 1966); ANDREWS, 1967, p. 888, PI. 113, fig. 14.

Phragmodus undatus Branson and Mehl, ANDREWS, 1967, p. 896, 897, Pi. 114, fig. 10.

The description of Phragmodus inflexus Stauffer given by Webers

(1966) is emended here to include elements of the form-species Cyrton­ iodus CCTnplicatus Stauffer. This collection contains 204 elements of 114

th e form-species Phragmodus inflexus « m dichognathiform elements and

88 cyrtoniodiform elements, and the ratio of 2:1:1 between these elements

suggests that the skeletal apparatus included 4 phragmodiform, 2 dichog-

nathiform and 2 cyrtoniodiform element* P« inflexus accounts for 1.51-

percent of the identifiable elements in this collection. It is the key

species to th e Phragmodus inflexus "zone” described by th e author in

this report.

Occurrence.—Phragmodus inflexus i s sparsely represented in th e

P ierc e, Ridley and th e loim r h a lf of th e Lebanon Limestone of Tennessee,

Specimens of i t occur in the lower 135 feet of the e:^osed Camp Nelson

limestone at its type section in Jessamine County, Kentucky, and in

the lower 315 feet of the Camp Nelson in the subsurface of Mason County,

Kentucky, It is represented in Ordovician rocks in the subsurface of

Richland County, Ohio; in th e Bony F a lls beds of Delta County, Michigan;

and in the M ifflin, Grand Detour, Nachusa and the lower half of the Quimbys

MLll Formation of Batchtoim Quarry, Illinois, Stauffer (1935^) and

Webers (1966) found elements of P, inflex u s in th e Glenwood Shale of

Minnesota,

Repository. —M icropaleontological C ollections, The Ohio S tate

University, Reference Slides from Sections 7OVL, 70VJ, 70V, 7024, 7OVG,

7OVI, 65X,

Figured Specimens. OSU 29659-29661

PHR4GM0DUS TORTUS Sweet, ms,

PI. 2, figs, 10, 19, 20 , 22; T ext-fig, 12K-N, Phragmodus undatus Branson and Mehl. BTHINGTON AND SCHüMr\CHER, 1969» p. ^72, Pl. 67, fig. 15.

Cyrtoniodus flexuosus (Branson and Mehl), BTHINGTON AND SCHUMACHER, 1969, p. 459, Pl. S ^fig . 11.

Phragmodus s p ., M03 K/lLENK0, 1971, p. 81, Pl. 13, fig. 5.

Subcordylodus sinuatus Stauffer, MOSKfilBNKO, 1971, p. 88 , 89, Pl. 13, f ig . 4.

The assembly of elements illustrated on PI. 2, figs. 10, 19, 20, and 22, is characteristic of an undescribed multielement species of

Phragmodus « -which W alter C. Sweet, of th e Ohio S tate U niversity, has named Phragmodus to rtu s in an unpublished manuscript dealing viith Ord­ ovician conodonts from the Kansas subsurface. It is the same species as th e one named Phragmodus sp. A by Sweet and others (1971). '

The 43 elements of Phragmodus to rtu s assembled during th is study are not described here, for Sweet's much larger collections yield material better suited for diagnosis of the species. Further, P. tortus is not regarded as a member of the Black River conodont fauna, for i t has not been reported from stra-ta of the Black River Group of New York.

Indeed, stra-ba in the Pamelia Formation in New York have yielded a few specimens of P. inflexus (Svreet and others, 1971, p. 175), and P. tortus i s known to range to top of, b ut n o t above, Chazyan rocks in Quebec,

However, specimens of P. tortus and P. inflexus have not previously been reported from the same section.

Phragmodus to rtu s and P. inflexus do occur in sequence in a sh o rt

Jttddle Ordovician section recovered in the pan American Da-vidson core from Richland County, Ohio. Hence a few ty p ic a l specimens are illu s tr a te d 116 here to document this important occurrence. Tentatively, the level

at which P, inflexus appears in the Davidson core is taken to be the lovjer boundary of th e “zone” of Phragmodus in fle x u s.

Occurrence. ««-Specimens of Phragmodus to rtu s occur in s ix sarnies between 3921 and 3935 fe e t in th e Daivdson core, Richland County, Ohio,

General distidbution of the species elserrhere in the North American

Midcontinent is given by Swet and others (19?l), Moskalenko (1971) has figured elements identical to those of P. tortus from the Middle

Ordovician of Siberia,

Repository.—^Micropaleontological Collections, The Ohio State

University. Reference Slides. 63X2-3921-3924, 3926, 3937,

Figured Specimens,—OSU 29663-29666,

PHRfkGMODUS UNEATÜS Branson and Mehl

P I, 2, f ig s , 1-4; T ext-fig. 12fi-D.

Phragmodus undatus gPANSON AND MSHL, 1933» p. 115, H 6, PI. 8, fig s , 22 - 26; BERGSTRœ AND S'.TSST, I 966, p, 369-372, P i. 28, fig s . 13-20 (includes synonymy through i 960),

1-Jhereas Phragmodus undatus i s abundantly represented in s tr a ta , younger than the ones considered here, specimens of i t have been obtained only in the upper most part or at the top of most sections sarg)led during this study. The species is represented by 2,777 elements or 10.41 percent of the collection. It is represented in the upper 6 feet of the

Tyrone Limestone of Kentucky; at the base of the Cloche Island beds of

Cloche Island, Ontario; in the Decorah Formation of central-eastern

VS-sconsin and northeast Im«a, Distribution elsewhere and in younger beds 117

i s discussed by Bergstrom and Sweet (I 966). P. undatus is a key to

recognition of Conodont Fauna 3 of Sweet and others (1971) and i t s

presence marks th e upper boundaiy of the Phragmodus inflexus "zone."

Repository. —M icropaleontological C ollections, The Ohio S tate

U niversity. Reference slid e s. 70V-36-39; 70ZA-665; 70VE-212; 7IZA-

1039, 1057, 1067, 1077, 1086, 1109; 70VH-9-l^. Figured Specimens.—OSU

Genus PLECTODINA S tau ffe r, 1935

Plectodina STAUFFER, 1935, p. 152.

Type Species.—Plectodina aculeata (STAUFFER), 1930.

PLECTODINA ACULS/iTA (S tauffer)

PI. 3, figs. 24-29, 31; Text-fig. 13A-F

Prioniodus aculeatus STAUFFER, 1930, p. 126 , PI. 10, f ig . 12.

Prioniodus? obliauus STAUFFER, 1930, p. 123, PI. 10, figs. 3, 4.

Plectodina aculeata (S tau ffer), BERGSTROM M:0 S^VBET, I 966, pp. 373-377, P I. 32 , fig s . 15, 16, PI. 33, fig s. 22, 23 , PI. 34, figs. 5, 6; T ex t-fig . 9A-F (includes synonymy through I 966).

Ozarkodina? oblloua (Stauffer), BERGSTROM /UO S'.VEET, 1966, pp. 343-351, PI. 33, figs. 6-9; PI. 34, figs. 7, 8; Text-fig. lOA-F*(includes synonymy through I 966).

Eoligonodina richmondensis Branson, Mehl, and Branson, 0B3RG, I 966, pp. 138, 139, PI. 16, figs. 14, 17; ANDREWS, I 967. pp. 889, 890, P I .I I 3, fig . 20 .

Ozarkodina robusta Stauffer, OBSRG, i 960, p. 11-0, PI. 16, figs. 10, 11.

Prioniodina delecta (Stauffer), 0BER3, I 966, p. l4l, PI. I 5, fig . 7, PI. 16, fig. 7; (part) ANDRE:VS, I 967, pp. 393, 899, PI. 113, figs. 6, 18 (not f ig . 17). 118

Subcordylodus delicatu s (Branson and Mehl) OBSRG, 1966, ou, 141, 142, Pl. 15, fig. . 21 ; ANDRSa, 196?, p. 899, Pl. 113, figs. 12, 13, 23.

Subcordylodus u la ttin e n sis (Branson and Mehl) OBSRG, i 960, p. 142, P l. 16, fig . 12.

Trichonodella exacts Ethington, OBSRG, I 966, p. 143, Pl. 15, fig. 11; ■ P l. 16, fig . 9.

Trichonodella recurva (Branson and Mehl), OBSRG, I 966, p. 143, Pl. 15, fig s . .5, ^

Trichonodella sulcata OBSRG, I 966, p. 144, Pl. 15, fig. 14.

Trichonodella tenuis (Bransnn and Mehl), OBSRG, 1966, p. l44. Pl. 15, fig . 9. Zygoonathus oyram idalis Branson, Mehl, and Branson, OBSRG, 19 66, p. 145, Pl. 15, fig . 13 .

Zygoamathus? sp. c f. Zî abnormalis (Branson, Mehl, and Branson), OBSRG, 1966, p. Ï45, P l. 15, fig. 24, Pl. I 6, fig s . 8, 15.

Ozarkodina .joachimensis AIÆî.RSiS. I 967, p. 895, Pl. 113, fies. 5, 15, Pl. 114, fig. 3.

Trichonodella sp. Al®REi'/3, I 967, p. 899, Pl. 113, fig. 19, Pl. 114, f ig . 17.

Zygoanathus sp. AKDRSVS, I 967, p. 900, Pl. 113, fig. 2, Pl. 114, fig. 20.

?Cordylodus concinnus (Branson and Mehl), BARMSS, I 967, p. 236.

?Cordylodus d elicatu s Branson and Mehl, BARKS3, I 967, p. 236.

?Solignodina robusta Branson. Mehl, and Branson. BARNES, I 967, p. 236.

îPrioniodina robusta (Stauffer). BARNSS, I 967, p. 236.

?Trichonodella sp. BARNSS, I 967, p. 236.

?Zygpgnathus c f. Z. m aysvillensis Puise and Sweet, BARNSS, I 967, p. 236.

Elements of Plectodina aculeata (S tauffer) and Ozarkodina?

obliqua (Stauffer) haye the same stratigraphie range and geographic

occurrence, the same size, color and mode of denticulation. The author agrees VTith Sweet and BergstrSm (I 969) that all these elements are parts Text-fig. 13A-L. Plectodina aculeata (Stauffer), (A-F); Plectodina n. sp., Votaw (G-L). Dichognathiform elements (A, G), ozarko- diniform elements (B, H), prioniodiniform element (C), trichond- delliform elements (D, J ), zygognathiform elements (E, K), cordylodiform elements (F, L), and an oistodiform element (I),

121 of the apparatus of a single species, Plectodina aculeata (Stauffer).

Collections at hand contain 6,095 elements assignable to P. aculeata. which is 22.32 percent of the collection. Ratios indicated by total collection frequencies (Table 1) suggest that the skeletal apparatus included 10 cordylodiform, 3 trlchonodelliform, zygognathiform, 8 ozarkodiniform, 6 prioniodiniform, and 6 dichognathiform elements.

Sweet and others (1971) suggest that P. aculeata characterizes

Faunas ? and S and that the common occurrence of this species and

Phragmodus inflexus defines Fauna 7. From the co llectio n s a t hand, the lower range lim it of P. aculeata can be extended below the first occurrence of Phragmodus inflexus and into th e range of Phragmodus tortus. Thus while P. aculeata is very abundant in the "zone" of

Phragmodus inflexus. as described here, it is kno'.^n from slightly older s tr a ta . Occurrence.—Plectodina aculeata is represented in almost every sample from every section studied. The distribution charts indicate th e occurrence of th is species. Sweet and others (1971) have summarized the range and distribution of this species elsewhere.

Repository. —M icropaleontological C ollections, The Ohio S tate

University.

Figured Specimens.,— OSU 29671-29676.

PLECTODINA N. SP., Votaw

PI. 3, figs. 12-23; Text-fig. 123-L. 122

Plectodina n, sp. is a multielement species with a skeletal

apparatus of trichonodelliform, zygognathiform, dichognathiform,

oistodiform, cordylodiform and ozarkodiniform elements. These elements

are nearly the same size and color, are laterally compressed, and

develop separated denticles on the processes. In zygognathiform,

dichognathiform, ozarkodiniform and cordylodiform .elements, the denticle

immediately adjacent to the cusp on either the posterior or lateral

process is fused to the cusp. This feature and the long sinuous

undenticulate anterior margin of the oistodiform (Pl. 3» figs. 12, 13),

•dichognathiform (PI. 3, figs. 1^, 15), and cordylodiform (Pl. 3, figs.

19, 23) elements are characteristic of the species. The zygognathiform

element (Pl. 3, figs. 17, 21) has a similarly sinuous lateral process, but it bears one or two small node-like d.enticles at the distal end.

These features and the fact that there is an oistodiform element in

place of the prioniodiform element of typical Plectodina distinguish

P. n. sp. from P. acu leata.

Occurrence.—Plectodina n. sp. is present in the Platteville

Formation of loi^a but is only sparsely represented. It is very abundant

in the Pierce, Ridley', Lebanon and basal Carters Formations of the

Central Basin of Tennessee. It appears to be restricted to the

Phragmodus inflexus "zone,”

A total of 1,421 elements representative of the species (Table 1) were recovered, and ratios between them suggest that the skeletal apparatus included 8 cordylodiform, 4 trichonodelliform, 2 zygognathiform,

4 ozarkodiniform, 6 oistodiform and 4 dichognathiform elements. Repository.—Micropaleontological Collections, Tne Ohio State

U niversity. Reference Sections, 70VH, ?OVI, ?OVJ, ?OVK, ?OVL, 70VM,

Figured Svntyoes. —OSU 29577-29082. ; unfigured paratypes OSU 29:83-29688

Genus POLYPL/iCOGNATHUS S tau ffer, 1935

Ehend. Bergstrom and Sweet, 1966

Polyplacognathus STAUFFER, 1935» p. 615.

Type Species. —Pol\mlaco?nathus ramosus STAUFFER, 1935.

POLYPUCOGNATHUS RAMOSUS Stauffer

Pl. 1, figs. 10, 11.

Polyplacognathus ramosus STAUFFER, 1935, p. 615, Pl. 75, figs. 23, 23-31, 37; BERGSTROM AND SV/EET, I 966, p. 336-333, Pl. 23, figs. 9-12 (included synonyry through i 960); E'THINGTON /iND SCHUMCKER, 1969, p. 473, Pl. 69, fig. 20.

Polyplaco?nathus bilobata SCHOPF, I 966, p. 69, Pl. 1, figs. 24-23.

The collection a t hand contains 331 specimens of the form-genus

Polyplacoznathus ramosus and 91 of P. b ilo b atu s. which suggests a ra tio of 8:2 between these elements in the apparatus, Webers (1966) suggested that ramosiform and bilobatiform elements occur in the ratio or 4:2 in the skeletal apparatus. Schopf*s (1966) collection contained similar elements in a ratio of 10:4. Bergstrom and Sweet (I 966) suggest an element ratio of 20:2 from the occurroice of these elements in the

Lexington limestone of Kentucky and Ohio. The 442 elements herein referred to P. ramosus are closely similar to previously described 124

representatives of the species and comprise 8,00 percent of the col­

le c tio n .

Occurrence. —Polvolacognathus ramosus occurrences in th is

co llectio n are summarized in the Frequency and D istrib u tio n Table in

Appendix and on the stra tig ra p h ie section figures (T ext-figs. 16-27).

The species ranges throughout the Phragmodus inflexus "zona”

I t is represented in th e Glenwood, P la tte v ille , and Decorah of Minnesota

(Stauffer, 1935» Webers, 1966), in the Kimms:fick of Missouri (Branson,

19^)» in the Harding Sandstone, Colorado (Sweet, 1955)» in the Trenton

Group of New York and the Cobum limestone of Pennsylvania (Schopf, 1966),

in the Lexington limestone of Kentucky and Ohio (Bergstrom and Sweet,

1966) , and the Copenhagen Formation of Nevada (Sthington and Schumacher,

1969).

Repository.—Micropaleontological Collections, The Ohio State

U niversity. Reference Sections. ?0V, 70 '/E,'t1ZA, ?0VH, ?0VI, ?0VM.

Figured Specimens. —OSU 29689, 29690.

Genus SCiiNDODUS lindstrom , 1955

Type Species.—Scandodus fu rn ish i LIHDSTROM, 1955.

Scandodus was established as a form-genus by lindstrom (1955) for fibrous drepanodiform conodont-elements, the cusp of which is twisted relative to the base so that the basal cavity opens to one side of the element rather than in a plane normal to the posterior cusp margin.

Subsequently, Lindstrom (1971) has recognized that the type form-species 125

of Scandodus is part of a form-transition series that also includes

elements he referred in 1955 to the form-species Drepanodus conulatus

and D, cyranoicus. Further, he concluded that other form-species of

Scandodus are apparently components of the sk e le ta l apparatus of different types of conodonts, including Drepanodus arcuatus, the type-

species of Drepanodus Pander, IS56. Consequently, he has redefined

Scandodus in a multielement sense (Lindstrom, 1971) to include

” . . . hyaline, mainly drepanodiform elements with symmetry transition: they have not much white matter in the cusp except for the gro^-d:h axis; the base is not much wider than the cusp and has a sharply conical basal cavity that in some elements opens to one side; the cusp has at least one sharp edge,"

The collection assembled during this study include a series of fibrous, morphologically intergradational simple cones, which display the essential characters of multielement Scandodus and apparently represent a previously undescribed species of that genus, herein named

Scandodus superbus, n. sp. As noted in the discussion that follows diagnosis of S, superbus. the distribution of this newly recognized species may be of stratigraphie importance.

Elements of Scandodus superbus differ only in detail from the ones assubled by Lindstrom (1971) in the multielement species S, brevibasis (Sergeeva), and except that they lack flange-like denticles on the posterior and lateral margins, they are also reminiscent of the array of fibrous elements that forms the skeletal apparatus of

Multloistodus compressus Harris and Harris, a species characteristic of the Joins and O il Creek Formations of Oklahoma and e a rlie s t Middle Ordovician rocks elsewhere in the southwestern and western United

States (Sweet and others, 1971). Indeed, until Lindstrom*s (1971)

revision of Scandodus appeared, the writer had considered tentative

assignment of the new species described belovx to M ultioistodus « even

though this would have required broadening the concept of that genus.

Now i t appears more lik e ly th a t Scandodus brevibasis (Sergeeva), which

ranges from the mid-part of the Volkhovian Stage into the basal part

of the Kundan Stage on the B altic Platform , or a species much lik e S. brevibasis. might well have been ancestral to both S. superbus. n, sp,,

and Multioistodus compressus Harris and Harris, The latter surely makes i t s appearance in North America before S, b rev ib asis became

extinct in northern Europe, although intercontinental correlations are not entirely clear in this critical interval. The earliest known occurrence of S, suoerbus is in the Cominco Core, Mason County, Kentucky, at a depth of II 30 feet, 100 feet above the reported top of the Knox

Dolomite, and 10 fe e t below the base of the Phragmodus inflexus "zone,”

SC/iNDODUS SUPERBUS Votaw, n. sp.

Pl. 1, fig. 1-k, 9; Text-fig, IhA-E.

Diagnosis.—A multielement species of Scandodus with a skeletal apparatus of morphologically intergradational fibrous elements that make up a form -transition se rie s composed of ad e nticulate trich o n o d elli­ form and zygognathiform elements and acodiform, drepanodiform and D

Text-fig. 14A-E. Scandodus superbus Votaw. Lateral outline of a drepanodiform element (A), lateral outline of an oistodiform element (B), lateral outline of an acodiform element (C), lateral outline of zygognathiform element (D), and lateral outline of a trichonodelliform element (E). Scandodus brevibasis (Sergeeva)

Scandodus superbus Votaw, n. sp. I M ultioistodus Harris and Harris

T ext-fig. 15. Comparison of the elements of Scandodus brevibasis (Sergeeva), Scandodus superbus Votaw, and M ultioistodus Harris 129 oistodiform components.

Description.—The trichonodelliform element of Scandodus superbus

(Pl. 1, fig. 4; Text-fig, 143) is a bicostate, bilaterally symmetrical u n it with an erect to somewhat proclined cusp. L ateral costae are sharp-edged, bisect the sides of the unit longitudinally, and extend from the basal margin to the apex of the cusp. The anterior margin is sharp-edged to very narrowly rounded; the anterolateral faces of the cusp are broadly convex; the posterolateral faces are flat to slightly concave; and the posterior margin is sharp-edged. The base is not markedly expanded and th e basal cavity is an asymmetrically subconical depression vrith its apex near the anterior margin at the point below and slightly posterior of the point of maximum curvature of the posterior margin.

Zygognathiform elements (Pl. 1, fig. 1; Text-fig. 14D) are asymmetric units similar in most of their characters to trichonodelliform elements, bu t distinguished from them by a sh o rter, somewhat more expanded base and by the fact that one of the lateral costae is closer to the sharp- edged posterior margin than the other one.

Acodiform elements (P l. 1, fig . 2; Text-fig 14C) have a somewhat more produced base than trichonodelliform or zygognathiform elements, but the lateral outline is othervzise similar to that of the trichonodel- liforra units. These elements are distinguish«i primarily by the fact that they are costate on only one side; the other side is flat or slightly concave. 130

Drepanodiform elements (Pl, 1, fig, 9» Text-fig, 14A) are compressed, bilaterally symmetrical, erect to slightly proclined cones with sharp or veiy narro^%y rounded anterior and posterior margins and lanceolate cross sections. The base is longer than that of trichonodelliform elements, but less produced than that of acodiform units; the basal cavity has slightly concave margins, but it is othend.se similar to that of acodiform elements,

Oistodiform elements (Pl, 1, fig, 3; Text-fig, 14B) are distinctly asymmetric, %d.th the base more inflated on one side than the other.

The cusp is biconvex, but lateral convexity is greatest on the side with the inflated base than on the opposite side, which is nearly flat in some specimens. The posterior margin of the cusp and the upper margin of the base join to form an angle of about 90 degrees.

A ll elements of Scandodus suoerbus in the co llectio n s a t hand are la rg e , dark amber to brown or black, and tra n slu cen t to transparent,

VJhite m atter is confined to narrow th re ad -lik e areas along the grovrth ax is.

Remarks, —Scandodus suoerbus is most closely related morpholog­ ically to S, brevibasis (Sergeeva) with the elements of which it is compared in T ext-fig, 15, The co state elements of S, suoerbus. however, are sharp-edged or very narrowly rounded anteriorly, whereas comparable structures in the apparatus of brevibasis are broadly rounded anteriorly and less conspicuously compressed laterally, Drepanodiform and oistodiform elements of the two species are comparable, but both 131

have some-rhat more d is tin c t bases in S. superbus than in S, brevibasis

and the oistodiform element of S, superbus is convex on the side toward

which the basal cavity opens rather than concave as Sergeeva (1963)

indicates is the case in the oistodiform element of S, brevibasis.

Occurrence.—Scandodus suoerbus is represented in the Murfreesboro,

Pierce, and basal Ridley Limestones in Tennessee. It is represented in

the lower 100 feet of the Camp Kelson Limestone in the type section

and from 975 to 1130 fe e t in th e Cominco Core, Mason County, Kentucky,

Elements of the species are presen t in th e Pan American Davidson Core

from 391^ to 39# feet in the Gull River Formation. The species is

represented in the lower 39 feet of the Pamelia Formation at Roaring

Brook, New York, and in the upper? feet at Bony Falls, Michigan.

Elements were recovered from th e Svxift Current, Cloche Isla n d , and

Unnamed Beds o f Grand Cloche Isla n d , O ntario. The lower lim it of the

range of th is species is not kno'-m, but i t reported from th e type

Ashjgy, Hogskin V alley, Tennessee, by Mr. Jack Cam es, of the Ohio State

University (personal communication). The upper range lim it, in the basal Ridl.ey Limestone of Tennessee, in the Pamelia Formation in New

York, and in the Unnamed Beds of Grand Cloche Islan d , t-rould suggest a distribution that is controlled by some factor of the environment

(Text-fig, 3). Its distribution seems to coincide %rith the trans­

gress ive phase of the Middle Ordovician sediments over the Eastern

Midcontinont.

Repository.—Micropaleontological Collections, The Ohio State U niversity. Reference Sections. 70VJ, 70VK, 70VL, 7OV, 70ZA, 65X,

70V3, 7OYE, 7OVG.

Figured Syntypes. —OSU 29691-29^95 ; unfigured paratypes 29 96-29700

Genus "TRUCHEROGNATHUS" Branson and Mehl, 1933

Trucheromathus BR/iNSON AND MSHL, 1933» p. 8^^.

Type Species. —Truchero~nathus d isto rta BRAIfSOIT AND MEHL, 1933.

"TRUCHEROGNATHÜS" sp. Votaw

Pl. 3, fig. 29. "Die collection at hand contains two fibrous bar-like elements

that are assigned to the form-genus Trucherognathus. These elements might be considered Polycaulodus. however the denticles are not of

approximately the same length nor do they completely occupy the upper surface of the base. These elements are placed in the form-genus

Trucheroinathus because they are bar-like fibrous elements, :>rith the longest denticle near the middle of the bar. The denticles are long,

slender, circular in cross-section, wddely separated, without costae

and in one plane. The lateral margins of the base are produced dovm’yard near the mid-point of the base to enclose a small depression. No basal cavity is present. The elements are transparent and colorless.

The apparatus to which these elements belong cannot be determined from this small collection, thus they are assigned to Trucherognathus as a form-genus and the name is set off by quotation marks to indicate this relationship. "Trueherognathus” sp, is represented in the Nachusa Formation,

Batchtarn .Quarry, I ll in o is , and the upper Lebanon Limestone, C entral

Basin, Tennessee.

Repository.—Micropaleontological Collections, The Ohio State

University,

Fie^ired Hypotype. —OSU 29701; % 9fÔ3^red syntype O3Ü29702 THE BLACK RIVER FAUNA

S p e c ie s Number Total Percent of C o ll e c t i o n

Drepanoistodus suberectus 4030 1 5 .1 1 suberectiform element 298 homocurvatiform element 3019 inclinatiform element 713

Panderodus gracilis 2930 1 0 .9 9 graciliform element 1925 gompressiform element 1005

Plectodina aculeata 6085 2 2 .8 2 cordylodiform element 1468 trichonodelliform element 1248 zygognathiform element 572 ozarkodiniform element 1129 priodiodiniform element 867 dichognathiform element 801

Appalachignathus delicatulus 111 0 .4 2 trichonodelliform element 13 zygognathiform element 12 eoligonodiniform element 10 falodiform element 76

Phragmodus inflexus 403 1 .5 1 phragmodiform element 204 dichognathiform element 111 cyrtoniodiform element

Belodina compressa 1387 5 .2 0 belodiniform element 1261 • éobelediniform element 126

Phragmodus undatus 2777 1 0 .4 1 phragmodiform element 1130 dichognathiform element 427 dichognathiform element 543 oistodiform element 677

Bryantodina? abrupta 60 0 .2 3 bryantodiniform element 47 prioniodiniform element 13

Scandodus superbus 255 0.96 trichonodelliform element 39 zygognathiform element 26 acodiform element 58 drepanodiform element 104 oistodiform element 28

Plectodina n. sp. 1421 5.33 cordylodiform element 414 trichonodelliform element 239 zygognathiform element 112 ozarkodiniform element 182 oistodiform element 288 dichognathiform element 186

Acontiodus alveolaris 31 31 0.12

Distacodus falcatus 179 179 0.67

Polyplacognathus ramosus 425 1.59 ramosiform element 333 bilobatiform element 92

Acodus mu tatus 58 58 0.22

"Oistodus" venustus 75 75 0.28

BeIodelia niger 81 0.30 trichonodelliform element 10 zygognathiform element 8 cordylodiform element 35 oistodiform element 28

Phragmodus tortus 43 0.15 phragmodiform element 24 cordylodiform element 3 dichognathiform element 3 cyrtoniodiform element 13

Oulodus serratus 508 1.91 oulodiform element 83 cordylodiform element 212 cyrtoniodiform element 51 trichonodelliform element 83 zygognathiform element 19 ozarkodiniform element 60

Panderodus panderi 7 7 0.03

Phragmodus cognitus 442 1.66 phragmodiform element 237 dichognathiform element 103 cyrtoniodiform element 102

Curtognathus robustus 856 3.21 erismodiform element 233 microcoeiodiform element 184 trucherognathiform element 299 curtognathifom element 35 cardlodelliform element 105

Erismodus radicans 2476 trichonodelliform element 276 zygognathiform element 221 ptiloconiform element 1231 dichognathiform element 398 cordylodiform element 350

Curtognathus typus 2006 microcoeiodiform element 137 bidentatiform element 174 tridentatiform element 410 cardlodelliform element 537 trucherognathiform element 303 curtognathiform element 310 polycaulodiform element 135

Chirognathus monodactylus 18 admirandiform element 1 delicatuliform element 5 multideniform element 4 monodactyliform element 8

"Trucherognathus" sp. 2 2 TABLE 2

Key to species by number

1. Drepanoistodus suberectus (Branson and Mehl)

2. Panderodus gracilis (Branson and Mehl)

3. Plectodina aculeata (Stauffer)

4. Appalachignathus delicatulus Votaw

5. Phragmodus inflexus Stauffer

6. Belodina compressa (Branson and Mehl)

7. Phragmodus undatus Branson and Mehl

8. Bryantodina? abrupta (Branson and Mehl)

9. Scandodus superbus Votaw

10. Plectodina n. sp., Votaw

11. Acontiodus alveolaris Stauffer

12. Distacodus falcatus Stauffer

13. Polyplacognathus ramosus Stauffer

14. Acodus mutatus (Branson and Mehl)

15. "Oistodus" venustus Stauffer

16. Belode11a niger (Serpagli)

17. Phragmodus tortus Sweet, ms.

18. Oulodus serratus (Stauffer)

19. Panderodus panderi (Stauffer)

20. Phragmodus cognitus Stauffer

21. Curtognathus robustus (Branson and Mehl)

22. Erismodus radleans (Hinde)

23. Curtognathus expansus Branson and Mehl

24. Chirognathus monodactylus Branson and Mehl

25. "Trucherognathus" sp., Votaw 138

TABLE 3

Key to Sample Localities

A. Lowville Quarry, Lowville, New York.

B. Roaring Brook, East M artinsburg, New York.

C. Coboconk, Ontario.

D. Coboconk, Ontario.

E. Cloche Island Area, Ontario.

F. Limestone Mountain, Michigan.

G. Bony Falls, Delta County, Michigan.

H. Pikes Peak roadcut, McGregor, Clayton County, Iowa.

I. Batchtown Quarry, Batchtown, Illinois.

J. Ridley's M ill, Rutherford County, Tennessee.

K. Coleman Cemetery, Rutherford County, Tennessee.

L. Pierce's M ill, Rutherford County, Tennessee.

M. Vulcan M aterials Co. Quarry, Una, Davidson County, Tennessee.

N. Camp Nelson, Jessamine County, Kentucky.

0. Cominco American Core, Mason County, Kentucky.

P. Pan American Davidson #2 Core, Richland County, Ohio.

Q. Van D riest Core, Sheboygan County, Wisconsin.

R. Glenburnie Quarry, Glenburnie Ontario. 139

TABLE 4

D istribution and frequency of conodont-eiements by locality» The species number and sang)le locality letter are taken from Tables 2 and 4*

Species Sample Locality Total

A B C,D E G H I J-M N 0 P Q R

1 30 17 42 83 34 1637 178 1244 305 166 181 171 42 4030

2 27 48 51 130 76 950 159 763 101 218 54 350 3 2930

3 42 74 57 519 109 36 272 170 1623 1060 2023 23 77 6085

4 50 8 15 38 111

5 7 12 236 39 25 84 403

6 2 17 6 49 24 703 94 279 40 120 42 11 1387

7 5 5 2516 102 43 106 2777

8 3 1 55 1 60

9 7 17 6 76 10 29 110 255

10 100 1321 1421

11 10 1 19 1 31

12 41 109 7 20 177

13 1 289 14 106 1 14 425

14 14 44 58

15 49 20 6 75

16 81 81

17 43 43

18 504 3 1 508

19 7 7

20 433 9 442

21 191 160 127 45 2 14 13 90 53 24 137 856 A B C,D E G H I J-M N 0 P Q R

22 85 225 154 68 26 21 194 450 635 325 169 1 123 2476

23 42 179 123 64 23 29 114 360 590 249 142 91 2008

24 10 3 2 3 18

25 1 1 141

TABLE 5

D istribution and frequency of conodont-eiements by sample. The species number and sample locality letter are taken from Tables 2 and 4.

Loc. Spl. Conodont Species

1 2 3 21 22 23

1 2 1 1 2 2 6 1 30 12 4 3 4 2 11 10 4 4 4 1 2 6 10 4 5 2 11 6 22 13 5 6 2 1 7 1 2 8 5 2 8 8 9 36 21 9 9 8 3 19 77 17 12

1 2 2 2 12 9 14 3 1 3 3 4 5 6 6 3 59 56 7 1 1 13 1 34 30 8 3 3 9 1 1 7 17 10 1 1 11 2 2 12 1 4 13 4 1 15 1 1 16 1 26 8 17 3 18 1 4 2 19 3 3 4 2 10 6 20 1 2 3 2 21 2 13 8 28 30 3 22 9 3 1 23 5 16 35 52 31 21 .24 3 12 16 25 1 4 4 1 26 2 5 27 3 13

1 3 7 1 5 2 7 1 5 3 21 24 9 7 24 25 5 4 5 5 3 15 20 6 9 1 1 34 58 30

1 1 2 3 16 5 1 2 2 3 2 4 3 4 23 16 2 20 12 3 4 1 2 8 18 4 1 5 2 8 9 9 6 1 4 1 2 4 3 1 7 7 8 3 2 3

1 5 3 27 7 11 15 2 2 13 37 5 7 6 3 8 5 1 11 10 5 3 9 4 5 6 7 7 32 16 1 11 7 2 6 16 7 1 2 1 8 2 22 2 1 3 3 6 9 1 3 2 2 10 2 2 17 2 10 10 . 4 11 10 3 9 1 5 10 12 21 68 278 7 5 3 5 4 7 13 24 18 16 11 7 1 2 2 14 5 7 2 2 1 1 2 15 1 41 1 1 1 1 4

1 4 1 11 3 1 2 1 1 3 2 3 3 3 4 3 5 4 1 3 2 5 5 11 22 5 5 3 6 2 5 37 6 1 2 7 3 32 10 1 5 1 2 8 14 20 20 11 2 10

2 138 43 85 5 7 1 3 177 49 72 21 1 1 2 4 39 8 23 3 3 5 21 16 27 2 12 1 2 6 27 11 17 13 7 65 27 65 41 22 1 8 17 8 7 10 1 9 412 643 53 110 1 16 7 9 10 21 1 5 414 1 11 28 7 2 1 229 12 178 28 9 57 1064 5 13 162 29 136 551 56 2 4 14 327 77 25 155 142 174 6 9 15 25 3 8 6

1 6 7 1 1 3 7 6 2 3 1 5 1 3 2 3 4 2 15 2 21 16 4 2 1 3 1 5 11 7 30 1 6 16 10 6 11 4 7 12 9 7 1 1 1 8 2 2 2 1 2 2 9 3 3 1 10 1 1 1 1 1 11 7 2 5 1 3 4 12 58 87 93 5 37 79 29 13 4 13 40 1 20 2 28 16 14 1 4 1 4 1 8 1 15 4 5 1 16 6 4 9 1 7 17 2 2 1 18 5 6 2 2 2 19 9 6 20 1 3 11 5 2 20 1 1 10 5 1 4 21 40 18 18 9 4 7

1 1 1 2 1 1 1 3 2 1 6 1 4 9 2 2 3 6 5 1 5 1 1 1 1 2 6 6 1 3 5 7 6 2 7 1 8 2 1 5 4 4 9 3 5 9 7 10 7 9 9 14 11 3 7 4 2 12 10 5 4 52 8 2 13 6 3 2 4 1 14 1 3 1 1 15 5 5 9 2 1 16 1 13 9 3 3 17 1 3 1 1 19A 6 6 1 4 2 19B 1 1 2 1 1 20 2 1 11 3 3 21 3 7 3 2 22 10 18 2 17 5 3 23 2 4 1 4 24 53 57 3 2 22 3 6 25 63 64 1 1 15 16 6 26 89 126 1 2 16 10 18 27 21 18 3 24 10 3 28 30 14 3 3 5 41 5 4 29 52 46 1 7 16 2 1 30 59 44 3 20 43 31 82 57 1 2 33 86 28 16 32 67 30 1 33 85 21 13 33 129 58 1 48 241 14 12 34 29 9 6 71 14 15 1 4 8 1 4 2 1 1 2 1 2 25 4 2 7 2 2A 1 4 1 4 2 4 2 3 1 1 1 5 3 1 2 3 5 3 3 6 2 3 1 1 2 7 5 1 3 1 2 8 3 4 4 6 6

1 4 5 6 6 15 10 2 11 6 6 2 3 27 19 13 33 3 63 2 3 4 44 15 9 1 127 2 12 82 22 15 5 35 1 24 1 22 3 59 46 55 6 27 2 20 2 5 7 34 37 33 7 72 22 16 9 9 1 25 218 58 47 8 5 1 1

1 41 1 4 4 51 1 3 2 23 1 13 6 28 3 1 3 14 20 9 5 13 4 31 12 5 1 8 5 14 7 5 2 1 1 6 29 16 16 5 2 1 5 7 13 4 9 1 3 3 8 6 6 4 1 1 3 9 24 13 8 7 4 1 10 7 5 11 1 12 13 1 13 6 7 6 13 3 1 6 5 3 3 14 1 4 1 2 6 1 15 6 7 24 7 7 3 16 6 3 10 1 3 6 17 4 2 1 1 1 18 8 6 1 4 19 2 3 1 3 1 1

1 1 1 6 2 1 3 3 1 1 2 2 7 2 4 4 17 7 4 2 11 5 5 1 7 1 1 1 8 2 9 2 2 14 1 1 10 1 3 1 11 1 12 2 3 2 2 13 4 13 94 77 14 1 15 2 1 55 8 15 17 16 1 3 3 145

17 4 22 5 14 24 18 3 188 15 42 40 19 7 3 247 2 53 45 20 11 191 1 3 1 59 47 21 93 1 2 13 50 53 22 1 50 3 4 10 23 3 4 1 24 1 25 2 1 4 5 26 1 1 6 6 27 2 1 1 2 28 1 3 4 29 1 1 30 1 2 4 3 31 3 2 1 1 32 1 1 3 5 33 1 1 1 1 34 3 6 3 1 10 5 35 1 2 3 6 1 40 10 4 41 2 2 1 1 1 42 2 1 1 43 1 2 44 6 4 2 1 2 45 1 2 1 47 2 4 1 2 4 48 2 1 1 2 1 49 2 1 2 50 1 1 2 51 2 4 2 3 8 3 53 1 1 1 1 56 1 2 57 7 3 8 58 1 2 59 1 2 4 11 6 60 1 1 1 1 5 61 2 62 1 3 2 2 63 5 2 64 2 2 65 1 66 5 2 1 3 67 2 51 1 15 11 12 68 11 1 61 3 21 57 78 69 23 12 166 1 4 70 98 70 71 72 73 1 36 12 13 91 3 3 14 37 78 23 292 11 66 24 38 6 8 3 4 4 39 5 8 4 28 13 0 1210 1 2 5 1205 1 1200 2 1195 1 1 1190 2 1185 2 1170 1 1145 1 4 6 4 1140 4 1135 3 1 1130 51 1 13 7 2 1120 1 1115 1 7 10 3 1 1 1110 3 1 8 2 1 3 2 1 1105 1 1 1 1100 2 6 2 1 1 2 2 1095 2 5 2 1090 1 1 1 1085 1 2 1 1080 1 1075 1 1 1070 1 1 1065 1 1 1060 1 1055 2 1050 1 1 1 1040 6 3 1035 2 2 31 3 21 16 1030 1 1 12 1 1025 2 1020 25 5 14 16 1015 1 8 6 3 1010 1 2 1 7 3 1005 1 1 3 1 1000 1 2 48 3 1 19 7 995 12 97 6 1 9 990 2 1 49 1 3 5 15 7 985 1 69 1 1 7 1 980 1 22 2 4 1 975 4 1 7 2 970 2 1 1 1 2 965 1 3 1 1 2 6 8 960 5 2 1 2 2 955 6 1 3 1 6 2 950 2 2 945 10 2 1 9 9 935 3 2 1 930 8 2 6 1 1 10 12 925 2 5 920 2 915 2 7 6 4 910 4 6 905 1 4 4 1 1 - to Ln CT> VO O I- lOUiOUiOO'-nOt-nOOUiOO'-nOUiOV/iOUiO'-nOUiOUiLnOUiO'-nOUiOUiO'-nOUiOUiO

00 NJ ov Ol ► - 4> UJ Ut VD C

cot— I— ^lOOvOvOV OOJ^h-JNC < ro ov cn to (>) h * h- Cn Ul CO 00 CO t— to cn t— to t— COH

- to o OO CO to Cn h- 'O to t— to t— CO Cn to tot— l— CO to CO h- O 3940 3 3939 1 3938 2 3937 3 3 1 1 3936 2 1 1 1 3935 8 13 13 2 12 12 3934 1 3 14 3 8 16 3933 1 2 11 8 8 3932 2 1 1 5 4 3931 2 5 3 7 5 3930 2 1 4 4 3929 3 1 3 3928 2 2 4 4 6 10 3927 1 2 2 4 3926 1 1 3 4 1 3925 4 1 9 1 3924 20 1 7 3 3923 14 34 11 17 12 3922 2 4 5 4 3921 7 2 7 1 17 4 3920 6 2 7 1 12 5 3919 3 2 18 1 2 4 5 3918 2 5 2 3917 15 56 4 77 1 1 3916 15 70 3 14 2 3915 22 1 167 1 1 3914 14 106 2 3 3913 1 148 i 3912 4 89 5 1 1 3911 5 84 11 3910 9 210 9 3909 13 72 31 3908 5 299 3907 4 186 3906 2 196 3905 48 1 3904 3 2 34 6 3903 2 8 2 3902 1 13 3 3901 7 1 3900 7 74 12

1175 5 4 4 1151 5 1 1129 7 9 16 2 1109 24 22 10 11 1086 19 36 29 1077 28 78 44 1067 12 15 6 1057 15 49 5 1048 9 30 1039 3 14 1017 7 34 1007 7 43 7 996 1 2 3 985 19 5 973 10 9 2

69B 42 4 79 11 137 123 91 150

EXPIANÀTION OF PLATE I

Figure Page

1-4, 9 Scandodus superbus Votaw

A il figured specimens from Collection 65X2-3917, Gull River

Formation, Pan American Davidson Core, Richland County, Ohio. X50

1. Lateral view of a zygognathiform element. OSU29691

2. Lateral view of an acodiform element. OSU 29692

3. Lateral view of an oistodiform element. OSU 29693

4. Lateral view of a trichonodeliiform element. OSU29694

9. Lateral view of a drepanodiform element. OSU29695

5 Erismodus radicans (Hinde)

Posterior view of a 'zygognathiform' element. X50. Collection

70VI-12. Nachusa Formation, Batchtown Quarry, Illin o is. OSU 29645 6-8 Drepanoistodus suberectus (Branson and Mehl)

All figured specimens from the Platteville Formation, Pikes Peak,

Iowa. Collection 70VH-9. X50.

6. Lateral view of an element of the form-species Drepanodus

homocurvatus. OSU 29638

7. Lateral view.of an element of the form-species Oistodus

inclinatus. OSU 29639

8. Lateral view of an element of the form-species Drepanodus

suberectus. OSU 29640

10, 11 Polyplacognathus ramosus Stauffer.

Both figured specimens from the Platteville Formation, Pikes

Peak, Iowa. Collection 70VH-14. X25.

10. Upper side of an element of the form-species Polyplacog-

nathus bilobata. OSU 29689 151

11. Upper side of an element of the form-species

Polyplacognathus ramosus. OSU 29690

12, 14 Oulodus serratus (Stauffer).

Both figured specimens from the Platteville Formation, Pikes

Peak, Iowa. Collection 70VH-9. X50.

12. Outer lateral view of an element of the form-species

Cordylodus grandis. OSU 29647

14. Lateral view of an element of the form-species Cordylodus

serratus. OSU 29648

13, 15, 17-19 Curtognathus robustus Branson and Mehl.

All figured specimens from the Lowville Formation, Roaring Brook,

New Y o rk . C o ll e c t i o n 7OVA-9 . X25.

13. Lateral view of a curtognathiform element. OSU 29624

15. Upper view of a cardiodelliform element with a denticulate

posterior process. OSU 29625

17. Inner lateral view of an erismodiform element. OSU 29626 18. Lateral view of a trucherognathiform element. OSU 29627 19. Outer lateral view of an erismodiform element. OSU 29628 16, 20-26 Curtognathus typus Branson and Mehl

A ll figured specimens from the Glenburnie Shale, Glenburnie,

Ontario. Collection 69B-14. X50.

16. Lateral view of an element of the form-species Polycaulodus

bidentatus. OSU 29630

20. Posterior view of a curtognathiform element. OSU 29631

21. 22. Posterior and anterior views of a cardiodelliform

element. OSU 29632

23, 26. Anterior and posterior views of an element of the 152 form-species Microcoelodus expansus. OSU 29633

24. Lateral view of a trucherognathiform element. OSU 29634

25- Lateral view of an element of the form-species Polycaulodus tridentatus. OSU 29635

154

EXPLANATION OF PLATE I I

Figure Page

1-4. Phragmodus undatus Branson and Mehl.

All figured specimens from the Platteville Formation, Pikes

Peak, Iowa. X50.

1. Postero-lateral view of an element of the form-species

Dichognathus brevis. Collection 70VH-10. OSU 29667

2. Lateral view of an element of the form-species Phragmodus

undatus. Collection 70VH-9. OSU 29668

3. Antero-lateral view of an element of the form-species

Dichognathus typicus. Collection 70VH-10. OSU 29669

4. Lateral view of an element of the form-species Oistodus

abundans. Collection 70VH-10. OSU 29670

5, 6. Bryantodina? abrupta (Branson and Mehl).

Both figured specimens from the Tyrone Limestone, Camp Nelson,

Kentucky. Collection 70V-37. X50.

5. Lateral view of an element of the form-species Bryantodina?

a b r u p ta . OSU 29619

6 . Lateral view of a prioniodiniform element. OSU 2 9 7 0 3

7-9. Phragmodus cognitus Stauffer.

All figured specimens from the Platteville Formation, Pikes

Peak, Iowa. Collection 70VH-9. X50.

7. Inner lateral view of an element of the form-species

Dichognathus brevis. OSU 29656

8. Lateral view of an element of the form-species Phragmodus

cognitus. OSU 29657

9. lateral view of an element of the form-species Cyrtoniodus 155

flexuosus. OSU 29658

10, 19, 20, 22. Phragmodus tortus Sweet, ms,

All figured specimens from the Gull River Formation, Pan American

Davidson Core, Richland County, Ohio. X50.

10. Lateral view of a cordylodiform element. Collection

65X2-3921. OSU 29663

19. Lateral view of an element of the form-species Phragmodus

tortus. Collection 65X2-3924. OSU 29664

20. Lateral view of a cyrtoniodiform element. Collection

65X2-3923. OSU 29665

22. Lateral view of a dichognathiform element. Collection

65X2-3923. OSU 29666

11-14, 17. Phragmodus inflexus Stauffer.

A ll figured specimens from the Gull River Formation, Pan American

Davidson Core, Richland County, Ohio. Collection 65X2-3909. X50.

11, 12. Lateral views of elements of the form-species Phragmodus

i n f l e x u s . OSU 29659

13. Lateral view of a dichogna thi form element. OSU 29660

14, 17- Lateral views of cyrtoniodiform elements. OSU 29661

15, 21. Acontiodus alveolaris Stauffer.

Lateral and posterior views. X50. Collection 70VJ-25. Lebanon

Limestone, Central Basin, Tennessee. OSU 29603

16. "Oistodus" venustus Stauffer.

Lateral view. X50. Collection 70VH-9. Platteville Formation,

Pikes Peak, Iowa. OSU 29646

18, 23-28, 30, 32, 35. Oulodus serratus (Stauffer). 156

All figured specimens from the P latteville Formation, Pikes

Peak, Iowa. Collection 70VH-9. X50.

18, 26. Posterior and anterior views of an element of the form-

species Zygognathus gyroidss. OSU 29649

23, 32. Posterior and anterior views of an element of the form-

species Oulodus primus. OSU 29650

24, 25. Lateral views of an element of the form-species

Ozarkodina concinna. OSU 29551

27. Lateral view of an element of the form-species Cordylodus

s e r r a t u s . OSU 29652

28, 30. Anterior and posterior views of an element of the form-

species Trichonodella recurva. OSU 29662

35. Inner lateral view of an element of the form-species

Cordylodus grandis. OSU 29704

29. Panderodus panderi (Stauffer)

Lateral view. X50. Collection 70VH-10. Platteville Formation,

Pikes Peak, Iowa. OSU 29655

31, 33, 34, 36. Curtognathus robustus (Branson and Mehl).

31, 33. Anterior and posterior views of an erismodiform element.

X25. Collection 70VA-9. Gull River Formation, Roaring Brook,

New Y o rk . OSU 29624

34, 36. Upper and lower sides of an element of the form-species

Cardiodella robusta. X25. Collection 70VC-6. Gull River

Formation, Coboconk, Ontario. OSU 29625

158

EXPLANATION OF PLATE I I I

Figure Page

1-3. Acodus mutatus (Branson and Mehl).

Figured specimens from the Pierce Limestone, Central Basin,

Tennessee. X50.

1. Lateral view of an acodiform element. Collection 70VL-3.

OSU29600

2. Lateral view of an acodiform element. Collection 70VL-3.

OSU 29601

3. Lateral view of an acontiodiform element. Collection 70VL-7.

OSU 29602

4, 5. Distacodus falcatus Stauffer.

Figured specimens from the Lebanon Limestone, Central Basin,

Tennessee. X50.

4. Lateral view of an asymmetrical element. Collection 70VJ-33.

OSU 29636

5. Lateral view of a symmetrical element. Collection 70VJ-32.

OSU 29637

6-11. Belode11a nlger (Serpagli).

Figured specimens from the Pierce Limestone, Central Basin,

Tennessee. Collection 70VL-3. X50.

6. Lateral view of an oistodiform element. OSU 29612

7. 8. Lateral views of an asymmetrical belodeHiform element.

OSU 2 9 6 1 3

9 . Lateral view of a symmetrical belodelliform element. OSU 29614 10, 11. Lateral views of a symmetrical belodelliform element.

OSU 29615 12-23. Plectodina n. sp., Votaw.

Figured specimens from the Lebanon Limestone, Central Basin,

Tennessee. Collection 70VJ-33. X50.

.12, 13. Lateral views of an oistodiform element. OSU 29677

14, 15. Inner and outer lateral views of a dichognathiform

element. OSU 29678

16, 20. Anterior and posterior views of a trichonodeliiform

element. OSU 29679

17, 21. Anterior and posterior views of a zygognathiform

element. OSU 29680

18, 22. Lateral views of an ozarkodiniform element. OSU 29681 19, 23. Lateral views of a cordylodiform element. OSU 29682 24-28, 31. Plectodina aculeata (Stauffer).

Figured specimens from the Gull River Formation, Pan American

Davidson Core, Richland County, Ohio. Collection 65X2-3910. X50.

24. Inner lateral view of a dichognathiform element. OSU 29671 25. Postero-lateral view of a xygognathiform element. OSU 29672 26. Posterior view of a trichonodeliiform element. OSU 29673 27. Lateral view of a cordylodiform element. OSU 29674

28. Lateral view of an ozarkodiniform element. OSU 29675

31. Lateral view of a prioniodiniform element. OSU 29676

29. "Trucherognathus" sp., Votaw.

Lateral view of a "trucherognathiform" element. X50. Collection

70VI-12. Nachusa Formation, Batchtown Quarry, Illinois. OSU 29701 30, 34, 35. Chirognathus monodactylus Branson and Mehl.

30. Posterior view of an element of the form-species Chirognathus

multidens. X50. Collection 70VI-16. Nachusa Formation, 160 Batchtown Quarry, Illin o is. OSU 29620

32, 33. Panderodus gracilis (Branson and Mehl).

Figured specimens from the Decorah Formation, Pikes Peak, Iowa.

Collection 70VH-9. X50.

32. Lateral view of an element of the form-species Panderodus

compressus. OSU 29653

33. Lateral view of an element of the form-speceis Panderodus

g r a c i l i s . OSU 29654

36, 40, 41. Belodina compressa (Branson and Mehl).

Figured specimens from the Decorah Formation, Pikes Peak, Iowa.

Collection 70VH-14. X50.

36. Lateral view of an element of the form-species Belodina

c o m p re s s a . OSU 29616

40. Lateral view of an element of the form-species Belodina

g r a n d i s . OSU 29617

41. Lateral view of an element of the form-species Eobelodina

f o r n i c a l a . OSU 29618

37-39, 46. Appalachignathus delicatulus Votaw.

F ig u re d sp ecim en s from th e Camp N e lso n L im e sto n e , Camp N e ls o n ,

Kentucky. X50.

3 7 . Lateral view of an eoligonodiniform element. Collection

70V-3. OSU 29604

3 8 . Postero-lateral view of a xygognathiform element. Collection

70V-3. OSU 29605

39. Posterior view of a trichonodeliiform element. Collection

70V-4. OSU 29606

46. Lateral view of a falodiform element with a nearly complete denticulate anterior process. Collection 70V-4. OSU 29607

4 2 -4 5 . Erismodus radicans (Hinde).

Figured specimens from the Nachusa Formation, Batchtown Quarry,

Illinois. Collection 70VI-12. X50.

42. Posterior view of a microcoelodiform element. OSU 29641

4 3 . Inner lateral view of a ptiloconiform element. OSU 29642 44. Lateral view of an element with a denticulate anterO-

lateral process. OSU 29643

45. Lateral view of a dichogna thi form element. OSU 29644 TE I I I REFEREiCSS CITED

Agnew, A, F ,, and Sloan, Robert, 1956, Geol. Soc, America Guidebook S erie s, Schwartz (e d .), F ield Trip No, 2, Lower Paleozoic Geology of the Upper Mississippi Valley, p. 91, 92.

Amsden, T. W,, and M U e r, A. K ., 19^2, Ordovician conodonts from th e Bighorn Mountains, Wyoming: Jour, Paleontology, v, l6, p, 301- 306, P I, ^1,

Andrews, H, E ,, 196?» Middle Ordovician conodonts from the Joachim Dolomite of eastern Missouri: Jour, Paleontology, v. p, 881-901, PI, 112-11^^,

Barnes, C, R,, 196?, Stratigraphy and sedimentary environments of some Wilderness (Ordovician) limestones, Ottawa Valley, Ontario: Canadian Jour, Earth Sciences, v, 4, p, 209-2#, 14- figs,, 3 table,

Barnes, C, R ,, Sass, D, B ,, and Monroe, D, A., 1970, Preliminary studies of the ultrastructure of selected Ordovician conodonts; Royal Ontario Museum, Life Sciences Division, Contributions, v, ?6, p, 1-24, Pis. 1-10.

Barnett, S, G,, III, 1965» Conodonts from the Jacksonburg Limestone (Middle Ordovician) of northwestern New Jersey and eastern Pennsylvania: Mcropaleontology, v, 11, n, 1, p, 59-30, Pis, 1- 2,

Bergstrom, S, Vi,, 1971» Conodont B iostratigraphy of the Middle and Upper Ordovician of Europe and Eastern North /imerica; Geol. Soc, America Mem, 127, p. 83-157» P is, 1» 2, T ex t-fig s, 1-14,

Bergstrom, S, M,, and Sweet, W, C ,, 1966, Conodonts from the Lexington lim estone (Middle Ordovician) of Kentucky and i t s la te r a l equivalents in Ohio and Indiana: Bull. Am. Paleontology, v, 50» • no. 229, 441 p ,,. 8 P is,

Berry, W, B, N., I960, Correlation of Ordovician graptolite-bearing sequences, XXI I n t. Geol, Cong,, Copenhagen, Repts, P t. 7» p, 97-105,

Berry, W, B, N,, 1964, North American Ordovician graptolite succession (a b s,): Geol. Soc, America Spec. Paper 76, p, 14, Bradshaw, Lael E ., 1969, Conodonts from the Fort Pena Formation (Mddle Ordovician), Marathon Basin, Texas: Jour. Paleontology, V. 43, No. 5, p. 1137-1168, Pis. 131-137.

Branson, E. B ., 1944, The Geology of Missouri: Univ. Missouri S tudies, V . 19, no. 3, 535 p . , 49 P is.

Branson, E. B ., and Mehl, M. G., 1933» Conodont Studies: Univ. Missouri Studies, Ÿ. 8, nos. 1-4, p. 1-349, Pis. 1-28.

Branson, E. B ., and Mehl, M. G., 1943, Ordovician conodont faunas from Oklahoma: Jour. Paleontology, v. 17, p. 374-337, P is. 63, 64.

Branson, S. B ., and Mehl, M. G. ,1944, Conodonts, in Shimer, H. W., and Shrock, R. R ., Index F o ssils of North America: New York, John Wiley and Sons, p. 235-256, P is. 93» 94.

Carlson, C .S ., I960, Stratigraphy of the Winnipeg and Deadwood Formations in North Dakota: North Dakota Geol. Surv. B ull., V. 35, p. 1-146, Pis. 1-2.

Case, E. C ., and Robinson, W. I . , 1915, Geology of Limestone Mountain: Michigan Geol. and B iol. S urv., Publ. 13, Geol. Ser. 15, p. 1Ô7-181.

Clarke, J . M., and Schuchert, C. W., 1899, the Nomenclature of the New York Series of Geologic formations: Science, v, 10, p. 8?4~373.

Collinson, Charles, I 963, Collection and preparation of conodonts through mass production techniques: Illinois Geol, Surv. Circ. 343, 16 p., iilus.

Conrad, T, A., 1936, F ir s t annual report on the geological survey of the th ird d is tr i c t of the S tate of New York: New York Geol, Surv., 1st /innual Report, Albany, p. 155-186.

Cooper, G. A., 1956, Chazyan and related brachiopods: Smithsonian Misc. C o ll., V . 127 , Pub. 4253, p t. 1, 1024 p.

Cullison, J. S., 1938, Dutchtown fauna of southeastern M issouri: Jour. Paleontology, v. 12, p. 219-223, PI. 29.

Cushing, H. P., 1903, Lower portion of the Paleozoic section in north­ western New York: Geol. Soc. America, Bull., v. 19, p. 155-176.

DeMott, L. L ., 1964, T rilo b ite co rrelations of Black River-Trenton s tra ta between Wisconsin and New York (abs): Geol. Soc. America Spec. Paper 76, p. 40, Dinsley, D. L,, and Barnes, C, R., Sedimentary environments and conodonts faunas of some Mddle Ordovician limestones in the Otta^ra V alley (abs): Geol. Soc, .'imerica, Spec, Paper ?5, p. 45- 46.

Eaton, Azios, 1324, A geological and agricultural survey of the district adjoining the Brie Canal in the State of Ne:-r York, Albany, p. 1-92,

Ethlngton, Raymond L ,, 1959» Conodonts of the Ordovician Galena" Formation (Io:-ra): Jour, Paleontology, v, 33» P. 257-292, Pis, 39-41,

Ethington, R, L ., and Schumacher, Dietmar, 1969, Conodonts of the Copenhagen Formation (Middle Ordovician) in ce n tral Nevada: Jour. Paleontology, v, 43, p, 440-434, Pis, 67- 69.

F isher, D, W,, 19°3» C orrelation of the Ordovician rocks in Nem York S tate: New York S tate 26is, and Sci, Service, Geol, Surv, Map and Chart Ser,, No, 3 (chart and text).

Flower, R, H ,, 1S'57, Studies of the A ctinoceratida: New Mexico Bur. Mines and M ineral Resources, Mem, 2, 101 p ., I 3 P is ., 5 T ext-fig.

Furnish, 'i, M,, Barragy, E. J . , and M iller, A. K.» 1935» Ordovician fossils from the upper part of the type section of the Deadwood Formation, South Dakota: Am, Assoc, Petrol, Geol, Bull,, v, 20, p. 1329- 1341, Pis, 1-2,

G lenister, A. T ,, 1957, Conodonts of the Ordovician Maquoketa formation in Iowa: Jour, Paleontology, v, 31 , p, 715-735, Pis, 85-33,

Grabau, A. If,, 1909, A revised classification of the North /imerican Lower Paleozoic: Science, v. 29, p. 351-355,

Graves, R, , and E lliso n , Samuel, 1941, Ordovician conodonts of the Marathon B asin, Texas; Univ. Missouri School of Mines and Metallurgy, Tech, Ser,, v. 14, p. I-I 6, Pis. 1-3.

Hall, James, 1847, Paleontology of New York, v, 1, containing descriptions of the organic remains at the lower dimension of the New York syster.- (equivalent to the lower Silurian rocks of Europe), 313 p., /ilbany,

Hamar, G,, 1956, The Middle Ordovician of the Oslo Region, Norway, Preliminary report on conodonts from the Oslo-Asker and Ringerike districts: Norsk, Geol, Tidsskr,, v, 46, p, 27-83, Pis, 1-7» 6 fig s . Hintse, L, F ,, 1951, Lower Ordovician detailed stratigraphie sections for western Utah: Utah Geol, and Mn. Surv, Bull, 39, p. U-23. yofnan, H, J , , 1963, Ordovician Chazy Group in southern Quebec: M , Assoc, Petrol, Geol, Bull,, v. ^7, p, 270-301, illus,

Hussey, R, C ., 1952, The fflddle and Upper Ordovician rocks of Michigan: Michigan Geol, Survey Div,, Pub, Geol. Ser, 39.

Jeppson, L,,^^ 1969, Notes on some Upper Silurian multielement conodonts: Geol, Foren, Stockholm Forhandl, 91, P. 12-2^,

Kay, G. M,, 1929, Stratigraphy of the Decorah formation: Jour, Geol., V, 37, p. 639- 671. Kay, G. M., 1937, S tratigraphy o f the Trenton Group: Geol, Soc, America, Bull,, v, 48, p. 233-302,

Kay, G, M. 5 1947» Bolarian Series of the Ordovician (abs): Geol, Soc, /imerica. Bull,, v, 57, p. 1193-H99.

Kay, G, H., 1948, Summary of the Middle Ordovician bordering the Allegheny synclinorium: Am, Assoc, Petrol, Geol. Bull.: v, 32, p. 1397-1416.

Kay, G, M., I 96O, Classification of the Ordovician System in North America: Inter, Geol. Congr., XXI Session pt, 7, Proc, Sec, 7, p. 23-33. Kay, G, M., 1963, Ordovician formations in northwestern New York: Natur, Can,, v. 95, p. 1373-1373,

Kohut, J , J , , 1969, Determination, statistical analysis, and inter­ p retatio n of the Cincinnati Region (Ohio, Kentucky, and Indiana): Jour, Paleontology, v. 43, p. 392-412, 6 fig ,

Kohut, J. J ,, and Sweet, W. C,,1963, The Upper Ordovician Standard X, Upper Maysville and Richmond conodonts from th e C incinnati Region of Ohio, Indiana, and Kentucky: Jour, Paleontology, v, 42, p, 1456-1477, Pis, 185, 186, 3 Text-figs, liberty, 3, A., 195^!-, Ordovician of ^ianitoulin Island: Micliigan Geol, Soc, Fieldbook for Excursion to Hanitoulin Island, p. 9-13.

L iberty, B, A ., 1969, Paleozoic Geology of the Lake Simcoe Area, Ontario: Geol, Surv, Canada Mem. 355, 201 p. Idndstrom, î^ aurits, 1964, Conodonts, E lsevier Pub, Co., Amsterdam, 196 p ., 64 fig s .

Lindstrom, M aurits, 1971, Lower Ordovician Conodonts of Europe: Geol, Soc, America Mem, 127, p. 21-61, PI, 1, Text-figs, 1-20,

Lindstrom, Maurits, and Ziegler, W illi, I 965, Bin Conodotentaxon aus vier morphologische verschiedsnen Typen: Fortschr, Geol, Hheinld, u, Westf. 9, p. 209-213,

LongiTell, C, R ,, and Mound, M, C ,, 1967, A neif Ordovician formation in Nevada dated by conodonts: Geol, Soc, /imerica. B u ll,, v, 73, p. 405-412,

Moskalenko, T, A,, 1970, Conodonts of the K rivolutsk beds (Middle Ordovician) Sibirian Platform: Academy of Sciences of the U,S,S,R,, Transaction of the Institute of Geology and Geophysics, V , 61, p, I - I I 6, Pis, 1-14,

Mukherji, K,. K ., I 969, Supratidal carbonate rocks in the Black River (Middle Ordovician)Group of Southwestern Ontario, Canada: Jour, Sed, P)t,, V , 39, p . 1530- 1545, fig . 1-5. M uller, Klaus J , , and Kogami, Yasuo, 1971, Uber der Feinbau der Cono­ dont en: Memoirs of the Faculty of Science, Kyota Univ., Series of Geology and Mineralogy, v, 38, p, 1-87, Pis, 1-22,

Nosow, Edmund, and McFarlan, A, C ,, I960, Geology of the ce n tral Bluegrass Area; Geol, Soc, /uaerica. Southeastern Sec, Guidebook, Field Trip, no, 1,

Oberg, Roland, I 966, Winnipeg conodonts from Manitoba: Jour, Paleon­ tology, V , 40, p, I 3O-I47, P is, 15, 16,

Okulitch, V, J,, 1939, The Ordovician section a t Coboconk, Ontario: Royal Canadian Inst, Trans,, v, 22, p, 319-339.

Pander, C, H,, 1356, Monographie der fossilen Fische des silurischen System der Russisch-Baltischen Gouvernements: K, Akad, W iss,, St, Petersburg, 91 p., Pis, 1-9.

P ulse, R, R ,, and Sweet, W, C ,, I960, The American Upper Ordovician Standard I I I , Conodonts from th e FairvieiT and McMillan formations of Kentucky, Ohio and Indiana: Jour, Paleontology, v, 34, p, 239-264, Pis, 35-37. Rhodes, F, H. T ., and Wingard, Paul 3 ., 1957, Chemical composition, microstructure, and affinities of the Heurodcntiformes ; Jour, Paleontology, v, 31, p. 443-434, 2 Text-fig,

Rigby, J, K., 1953, LotTer Ordovician graptolite faunas of western Utah; Jour. Paleontology, v. 32, p. 907-91?,

Ross, J. R, P ., 1964, Champlainian cryptostome Bryoaoa from New York State: Jo’ir. Paleontology, v, 33, p. 1-32, Pis, 1-3,

Schopf, T, J , M,, 1966, Conodonts of th e Trenton Group (Ordovician) New York, southern O ntario, and Quebec: New York S tate Mus, Bull, 405, 105 p ., 6 P is,

Schuchert, C. "i,, and Barrell, J., 1914, A revised geologic timetable for North /imerica: Amer, J, Sci., Ser. 4, v, 33, p, 1-2?,

Schwab, K arl, W,, I 965, Microstructure of some Kiddle Ordovician Conodonts: Jour. Paleontology, v. 39, p. 590-593» P is, 69-70, 3 Text-figs.

Seddon, George, and Sweet, W, C ., 1971, /n écologie model fo r Conodonts: Jour. Paleontology, v, 45, p. 619-330, 3 Text-figs,

Serpagli, Ehrico, I 967, I conodonti Dell'Ordoviciano superiors (Ashgilliano) delle Alpi Camiche: Soc. Pale on toi. Italiano, BoH, V, 6, p, 3O -U I, ta w . 6- 31 , fig,-testo 1-3.

Staesche, U ,, 1964, Conodonten^^aus dem Skyth von Sudtyrol: Neues Jahrbuch, Geologie u. Palaeontolozie Abhandlung, v. 119, o. 24?- 306, PI, 23-32, figs, 1 - 67,

Stauffer, C, R,, 1935a, Conodonts of the Glenwood Beds: Geol, Soc, America, Bull,, v, 46, p, 125-163, Pis, 9-12.

Stauffer, C, R., 1935b, The conodont fauna of the Decorah Shale (Ordovician): Jour, Paleontology, v, 9, p, 596-620, Pis, 71-75.

Stone, G, L., and Furnish, W. M,, 1959, Bighorn conodonts of Wyoming: Jour. Paleontology,,v. 33, p, 211-223, Pis, 31-32, 1 Table, 1 T ext-fig,

Sweat, W. C., 1955, Conodonts from the Harding Formation (Middle Ordovician) of Colorado; Jour. Paleontology, v, 29, p. 226- 262 , P is, 27- 29. 169

Sweet, W. C., and Bergstrom, S ., 19^2, Conodonts from the P ra tt Ferry formation (Middle Ordovician) of Alabama: Jour, Paleontology, V . 36, p, 1214-1252, PI. 168-171 , 5 T ext-figs.

Sweet, If. C ., and BergstrSm, S. M., 19o9, The Generic Concept in Conodont taxonomy: Proc, North American P aleontol, Conv,, Part C., p. 157-173, 6 fig s.

Sweet, W. C., Ethington, R. L ., and Barnes, Christopher, 1971, North American Middle and Upper Ordovician Conodont Faunas: Geol. Soc, America Mem. 127, p. 165-193, P is. 1-2, 3 Te>rt-figs,

Sweet; Vr. C., Turco, C. A ., 'farner, E arl, and Vfilkie, L, C ., 1959, The American Upper Ordovician Standard I , Eden Conodonts from th e C incinnati Region of Ohio and Kentucky: Jour. Paleontology, V . 33, p. 1029-1063. P is. 130- 133.

Templeton, J . S ., and Willman, H. B ., 19o3, Champlainian Series (Middle Ordovician) in Illinois: Illinois Geol. Surv. Bull. 89, 260 p. Ttrenhofel, V/. H., and others, 1954, Correlation of the Ordovician formations of North /imerica: Geol. Soc. America, Bull., v. 65, p. 247- 293.

Vanuxem, Lardner, 1342, Geology of New York, p t. I l l , New York Geol, Survey, 306 p.

W a llister, 0. H ., 1964, Conodonten des S ilu rs: Eess, Landesamts Bodenforschuug, Abhandl., Hft. 41, I 06 p ., 32 P is.

Webers, G. F., I 966, The Middle and Upper Ordovician Conodont faunas of Minnesota: Minnesota Geol. Survey, Spec. Publ. SP-4, p. 1-123, P is. 1 - 15.

Weyant, Marcel, 1963, Conodontes ordoviciens de l* ile Hoved (Archipel ' Arctique Canadien): Bulletin de la Société Linneenne de Normandie, p. 20-66, Pis. 1-6,

'vVhittington, H. B., 1959, Silicified Middle Ordovician Trilobites: Harvard C oll., Muséum Comparative Zoology, Bull. 121, p. 371- 496, 36 Pis., 3 figs.

Wilson, A. E., 1936, A synopsis of the Ordovician of Ontario and western Quebec and the related succession in New York: Geol. Surv, Can., Mem. 202, pt. 1, p. 1-20, 170

Wilson, C, W,, J r . , 1948, Geology of N ashville, Tennessee: Tenn Dept. Cons. Div, Geol., Bull. 53» 172 p., 29 Pis.

%lson, 0, W., Jr., 1949, Pre-Chattanooga stratigraphy in Central Tennessee: Tenn. Dept. Cons. Div. G eol., B ull. 56, 40? p ., 28 P i s .

Winder, C. G., I 96O, Paleoecological interpretation of Middle Ordovician stratigraphy in southern Ontario, Canada: Inter. Geol. Congr., Xn Session, Repts., pt. 7, Proc. sec. ?, p. 18-27,

Winder, C. G,,. 1966, Conodonts from th e upper Coburg Formation (Late Middle Ordovician) at Colbume, Ontario; Jour, Paleontology, V . 46, p. 46- 63, PI. 9-10.

Wolcott, Don E.', I 969, L ittle Hickman Quad., C entral Kentucky, United States Geol. Surv., Map GQ 792.

Young, R. P ., 1943, Black River stratigraphy and faunas, Pt. 1 and II*' Am. Jour. Sci., v. 241, p. 141-166, 209-240.

Youngquist, W. L ., and C ullison, J . S ., 1946, The Conodont fauna of the Ordovician Dutchtoim formation of Missouri: Jour. Paleontology, V . 20, p . '579-590, Pis. 89- 90. 70VK 70VL 70VJ 70VM 50 ft . %_

Drepanolatodus suberectus ' s Ml-CS---- &£Î-S3------— ^WiU Panderodus gracilis Erlsmodus radleans ’ Î —H—Hiîi'H .Curtognathus typua L 2— Siw'ü-diw—CXj ------—------M f H Ple,ctodlna aculeata I W-GÜ-----HtilitHihHi— Plectodlna n. sp. LÎ-i-3-3-ÎW i3:3-HI 'Scandoduc superbus i 8—fititmsücmiHi Appalachlgnathus dellcaCulus h -8 B-H mi Chlrognathus monodactylus -ÎH ------Î- ■g Belodlna compressa . c k ::3h i Belodellji nlger CJ23— H - "0— m - —H-iHHH)— 9 Fhragmodus InfLexus Hl------8 MHH "Olstodus" venuseus - m — Acontlodus alyeolarls MT- Dlstacodus falcatus [ H - h - H iS \ Acodus mueatuB SütH-i Polyrlaccgiiathus ramosus Camp Nelson Kentucky 70V

_Lexlngton Ls.

Tyrone Ls.

Oregon Ls.

Comp Nelson Ls.

£ £ Text-fig. 17. Stratigraphie section and conodont species distribution at Camp Nelson, Kentucky. COMINCO AMERICAN CORE CA 38 MASON CO, KENTUCKY g g, s 5 -o 5 g SEC. 15, T. AA, R. 6 8 | " i t i n 3 § § i

M OPkOPNPUtQcl______COCQPN xxxxxxxxx X = “ g LEXINGTON LS. J 1 1 g- Î

OREGON. LS. I i l " = n z i = I — = I X = X r : i I:; - X 3C ^ — =C - CZI

m CAMP NELSON LS. X 1 = = - — _

= . î l = I i r Z I _ -I

Text-fig. 18. Stratigraphie section and conodont species distribuition in the Cominco Core, Mason County, Kentucky. Pan American Pet. Davidson 2 Richland Co., Ohio

3 9 0 0 O

XX

3 9 6 0 rz Text-fig. 19. Stratigraphie section and conodont species distribution in the Pan American Davidson Core, Richland County, Ohio. Block River Section olong Roaring m Brook Mortlnsburg, N.Y.

27 Rockiond Fm.

Choumont Fm.

2 0 -

Lowville Fm.

8

Pomello Fm.

'T.

Text-fig. 20. Stratigraphie section and conodont species distribution at Roaring Brook, New York. Lowville Quarry

Lowville, New York

Rockland Fm. w ^ s

•Oî î 60 l m i g. i œ i aj m Choumont Fm. « « g o ^ ^

I d I 1 11 II I

□ r n

~r~T

i i r r a

;-fig. 21. Stratigraphie section and conodont species distribution at Lowville Quarry, Lowville, New York. OKULITCH s TYPE SECTION COBOCONK, ONTARIO li

7 Bobcoygeon Fm. 6

5

4

3

2 Gull River Fm.

I G

5

4

3

2

I Shadow Loke Fm.

Text-fig. 22. Stratigraphie section and conodont species distribution at O k u litch 's type sec tio n , Coboconk, O ntario. Cloche Isiond Area

O n tario

7 0 V E

Cobourg Fm. : "g

Unnamed Beds s a

1=^ Cloche Island Beds

~ P T O

H 3

Swift Current Beds r z E

5 =

Basai Beds

Huronlon Quartzite Text-fig. 23. Stratigraphie section and conodont species distribution in the Cloche Island area, Ontario. o 00 g 00 3 k 00 VAN DRIEST CORE •sügiis^^sjs ss SEC. 12, T. 13N., R .22E . SHEBOYGAN CO., WISCONSIN Il E «3 # U I I ^ g S 5 « § “ “ ...... % g 7IZA g S « ^ s.-slï l & i l Is

Ezn î

i Z n

a DECORAH FM. r z i PLATTEVILLE FM., î "ext-fig. 24. Stratigraphie section and conodont species distribution in the Van Driest Core, Sheboygan County, Wisconsin. BONY FALL S , DELTA CO., MICHIGAN

SEC. 2 , T 4IN ., R.24W .

70VG

r z E

8

7 TZL 6 I.

5

4 -

3 -

2 _

I 1 r

lilmil

Text-fig. 25. Stratigraphie section and conodont species distribution at Bony FallsÎ Delta County, Michigan. 10 ft

Drepanolatodus suberectus 1 Fanderodus gracilis -B— 4 — f - H - 4 ^ 5 ■ Belodlna compressa H M h —J-----0 Polyplacognathus ramosus 4 4 — J Erlsmodus radlcans — ^ Curtognathus typus Plectodlna■ -B—S------1 !------1 — Q Plectodlna aculeata 5-H- "Olstodus" venustus Fanderodus panderl -5------1 I— 5— {- Acontlodus alveolarls Dlstacodus falcatus Acodus mutatus

Oulodus serratus

Phragmodns cognltus Fhragmodus undatus BATCHTOWN QUARRY

BATCHTOWN, ILLINOIS 5§g!:i

21

Quimbys MiD Fm.

Nochuso Fm.

10

Grand Detour Fm.

M if f lin Fim.

I Text-fig. 27. Stratigraphie section and conodont species distribution at Batchtown Quarry, Illinois. Central Camp Cominco Pan Am Roaring Cloche Bony Van Driest Pikes Batchtown Central Basin Nelson Core Core Brook Lowville Coboconk Island Falls Core ' Peak Quarry Basin Tennessee Kentucky Kentucky Ohio New York Ney York Ontario Ontario Michigan Wisconsin Iowa Illinois Tennessee

Phragmodus

highest Phragmodus LSJ Infiexus

highest

Phragmodus

Text-fig.. 28. Correlation of the. Sections Studied Phragm odus