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PALEONTOLOGY AND PALEOECOLOGY OF THE NADA MEMBER OF THE BORDEN FORMATION (LOWER MISSISSIPPIAN) IN EASTERN KENTUCKY

DISSERTATION

Presented in Partial Fullfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University

by Aiguo Li, M.S.

*****

The Ohio State University 2000

Dissertation Committee: Dr. W.I. Ausich, Adviser Approved by Dr. L.E. Babcock Dr. Michael Barton Adviser Dr. S.M. Bergstrom Geological Sciences UMI Number 9962423

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Bell & Howell Information and Leaming Company 300 North Zeeb Road P.O. 00x1346 Ann Arbor, Ml 48106-1346 ABSTRACT

The Nada Member of the Borden Formation (Mississippian) in northeastern Kentucky was the delta platform deposit of the Borden delta. It consists mainly of siliciclastic mudstones with carbonates and siltstone interbeds. The dominant fossil groups that it contains are crinoids, brachiopods, rugose corals, and bryozoans. Biostratigraphic study bears out that the Nada Member is middle Osagean in age, and again, confirms the westward progradation of the Borden delta. The Nada Member represents the very distal part of the subaqueous delta platform, and it was more controlled by marine processes than by terrestrial influences. The Nada Member has beds with abundant phosphates and glauconites. Field and microscopic study of the phosphates and glauconites indicate that a major transgression occurred at the end of the time of Nada deposition. The Abandonment phase of the Borden delta in present-day northeastern Kentucky occurred toward the end of the time of Nada deposition. Community paleoecological study was carried out with the application of the concepts of community components, tiering, and guilds. Biotic interactions were represented in the Nada fauna by the platyceratid-crinoid, the platyceratid-tabulate coral, and the tabulate coral-crinoid relationships. The Nada community was compared with the Edwards ville Formation community of southern Indiana because they were deposited in similar delta platform environment, but at different times. The Edwards ville community is more diverse and has more guilds than the Nada community. The increase in diversity is a result of the increase in the number of guilds. Temporal changes in the communities ii (communia development or communia évolution) have attracted much recent attention in paleoecological smdies. A complete comparison of the Nada and Edwardsville mudstone communities was carried out in terms of taxonomy and trophic structures. The community development patterns displayed by the two communities do not support coordinated stasis, but instead, are indicative of coincident relative stability. Crinoids are the predominant group of fossils in the Nada Member of the Borden Formation. Systematics of the Nada Member crinoids are reviewed in this paper. One new genus and four new species occur in this fauna. The new genus is Discocrinus. The four new species are Uperocrinus acwninatus, Aorocrinus nodulus, Discocrinus protuberatus, and Atelestocrinus kentuckyensis. The dominant crinoid group in the Nada is monobathrid crinoids, followed by cladids, and disparids. The fact that monobathrid camerates dominated the Nada fauna in the mudstone facies counters the general pattern, in which crinoid faunas dominated by monobathrid camerates were largely in carbonate facies.

m Dedicated to my mother

IV ACKNOWLEDGMENTS

I owe thanks to many individuals who have helped me in the completion of this dissertation. In particular, my adviser. Dr. William I. Ausich has provided much needed help, both in my academic pursuits and in encouragement and enthusiasm for my dissertation project. I am especially grateful to him for his great insight and patience in revising drafts of my dissertation. I also want to thank my dissertation conunittee members. Dr. Loren E. Babcock, Dr. Michael Barton, Dr. Stig M. Bergstrom and Dr. Lawrence A. Krissek for their willingness to serve on my dissertation committee and for their advice. I thank William I. Ausich, Yuping Xu, Alex Li and Charles Mason for their assistance in fieldwork. I thank Stephen A. Leslie for his help in processing the microfossils. I also want to thank my fellow geology graduate students whose names are too many to be listed here. I want to thank Tom Kammer of West Virginia University, Charles Mason of Morehead State University of Kentucky and Royal H. Mapes of Ohio University for providing some fossil specimens. VUA

November 28, 1963 ...... Bom in Shandong, China 1983...... B.S., Beijing University Geological Sciences 1986 ...... M.S., China University of Geosciences, Geological Sciences 199 7...... M.S., The Ohio State University, Food Sciences and Technology 1998 to 2000...... Graduate Teaching and Research Associates, The Ohio State University

PUBLICATIONS

Li Aiguo, and Yang Shipu. 1989. Ontogeny, autecology and evolution ofCleiothyridina obmaxima McChesny (Bracluopoda). Geosciences, 3:175-184 (in Chinese). Li, Aiguo. 1994. Platyceratid gastropo^ from the Borden Formation of northeastern Kentucky and their biostratigraphic and paleoecologic implications. Geological Society of America, Abstracts with Programs, 26(5):50.

FIELD OF STUDY

Major Field: Geological Sciences Minor Field: Paleobiology and Paleoecology

VI TABLE OF CONTENTS

Page Abstract ...... ii Dedication...... iv Acknowledgments ...... v Vita ...... vi List of Tables ...... x List of Figures ...... xii

Chapters: 1. Introduction ...... 1 1.1 History and geological setting of the Borden D elta...... 2 1.2 Geology and paleoecology of delta platform deposits...... 7 1.3 Introduction to the Borden Delta Deposits northeastern Kentucky ...... 9 1.4 Research methods applied ...... 13 2. Biostratigraphy, sedimentology and the Borden delta progradation ...... 15 2.1 Facies analysis and sedimentology ...... 15 2.1.1 Interdistributary mudstone facies ...... 17 2.1.2 Carbonate stringer / tempestite facies ...... 21 2.2 Phosphates and glauconites in the Nada and their paleoenvironmental implications...... 27 2.3 Faunal analysis and biostratigraphy ...... 28 2.4 Westward progradation of the Borden Delta ...... 34 vii 3. Taphonomy, autecology and biotic-mteractions of the Nada fauna...... 38 3.1 Introduction to taphonomy ...... 38 3.2 Autecology of the major Nada fossil groups...... 40 3.2.1 Autecology of crinoids ...... 40 3.2.2 Autecology of brachiopods ...... 47 3.2.3 Autecology of trilobites ...... 52 3.2.4 Autecology of cephalopods ...... 54 3.2.5 Autecology of rugose corals ...... 55 3.2.6 Autecology of pelecypods ...... 55 3.2.7 Autecology of bryozoans ...... 56 3.3 New type of biotic-interaction between Platyceras (Gastropoda) and Cladochonus (Tabulata) ...... 56 4. Community paleoecology ...... 61 4.1 Introduction ...... 61 4.2 Nada platform community structure ...... 66 4.3 Comparison of community developments of the Nada Member with that of the Edwardsville Formation...... 74 4.4 Coordinated stasis or coincident relative stability, which one fits the picture better? ...... 83 5. Systematic description of the crinoid fauna with one new genus and four new species ...... 88 5.1 Introduction ...... 88 5.2 Locality and stratigraphy ...... 88 5.3 Faunal analysis ...... 89 5.4 Systematic paleontology ...... 93

6. Platyceratid gastropods and their biostratigraphic and paleoecologic implications ...... 134 6.1 Introduction ...... 134 viii 6.2 Location and geological setting ...... 135 6.3 Biostratigraphy and the Borden delta progradation ...... 135 6.4 Autecology of the platyceratids ...... 138 6.5 Systematic paleontology ...... 141 7. Conclusions...... 145

Appendices; A. Systematics of the non-crinoid fauna from Nada...... 148 B. Lithological thin sections descriptions...... 161 C. Description of the four measured Nada sections ...... 168 D. Locality information of fhe Nada...... 173

Bibliography ...... 175

IX UST OF TABLES

Table Page 2.1 Grain types of the Nada carbonates ...... 23 2.2 Microfacies in the Nada carbonates ...... 24 2.3 List of fossil taxa identifîed in the Nada Member ...... 30 3.1 Comparison of the size (mm) of average specimen with that of the specimen that was attached by Cladochonus beecheri (Grabau) ...... 60 4.1 Species level diversity of the Nada community ...... 67 4.2 Taxonomic and trophic relations of the Nada community...... 69 4.3 Examples of guilds in paleocommunities ...... 71 4.4 Distribution of guilds in the Nada community ...... 72 4.5 Early Mississippian community components ...... 73 4.6 Nada community components ...... 74 4.7 Taxonomic comparison between the Nada community and the Edwardsville community ...... 77 4.8 Genus and family level comparison of the crinoid fauna hrom Nada and Edwardsville mustone communities ...... 78 4.9 Trophic groupings in the Nada and Edwardsville communities ...... 80 4.10 Community components in the Nada and Edwardsville communities ...... 80 4.11 Guilds in Nada and Edwardsville communities ...... 83 4.12 Sources and causes for variability among communities ...... 85

X 5.1 Nada member crinoid fauna and occurrences ...... 91 5.2 Measurements of Uperocrinus acuminatus ...... 99 5.3 Measurements o f Aorocrinus nodulus ...... 104 5.4 Measurements of Discocrinus protuberatus ...... 110 5.5 Measurements of Atelestocrinus kentuckyensis ...... 122

XI LIST OF HGURES

Figure Page 1.1 Paleogeographic diagram of the progradation of the Borden delta...... 3 1.2 Locality map of the studies area ...... 5 1.3 Delta classification ...... 8 1.4 Borden Formation deposits in eastern Kentucky ...... 10 2.1 Differential weathering of the mudstones and siltstone beds ...... 18 2.2 Comparison of delta sequences in southern Indiana and eastern Kentucky ...36 2.3 Stratigraphie comparison of delta sequences in southern Indiana and northeastern Kentucky with the standard section in Iowa ...... 37 3.1 Parabolic filtration fan of the Ordovician camerate crinoid Rheocrinus aduncus ...... 42 3.2 Possible protective structures in crinoids ...... 44 3.3 Examples of crinoid epizoans ...... 46 3.4 Water current pattern created by brachiopods when feeding ...... 50 3.5 Morphological adaptations in brachiopods ...... 53 3.6 Tabulate coral Cladochonus beecheri grew spirally around the shell of gastropodPlatyceras acutirostre when the snail was still alive...... 58 4.1 Diagram of the three-factor ecospace utilization...... 64 4.2 Ecological pyramid of the Nada community ...... 68 4.3 Histograms of the trophic groupings in the Nada and xii Edwardsville communities ...... 81 4.4 Distributions of community components in the Nada and Edwardville communities ...... 82 5.1 The aboral cup structure of Discocrinus protuberatus showing the five rays and the anal plates that are grouped with C ray ...... I l l

5.2 Crinoid systematics illustration 1 ...... 127 5.3 Crinoid systematics illustration 2 ...... 129 5.4 Crinoid systematics illustration 3 ...... 131 5.5 Crinoid systematics illustration 4 ...... 133 6.1 Devonian platyceratids with randomly-scattered spines on the shell ...... 137 6.2 Mississippian platyceratids with regular pattern of spines ...... 140

xiu CHAPTER 1

INTRODUCTION

Although the main theme of the past decade in paleontological research has been evolutionary modes and tempos, including the ever popular topic of mass extinction, all evolutionary changes must have occurred in specific paleoecological contexts (all evolutionary “plays” must have been staged in specific ecological “theaters”). In contrast to ecology that deals with modem day ecosystems and has advanced considerably during the past decades, paleoecological studies (paleocommunity study in particular) are endowed with a geological time dimension and permit examination of paleocommunities and their changes from the unique perspective of a much longer time scale. This dissertation concentrates on the Nada Member of the Borden Formation in northeastern Kentucky. Previous work on the Nada Member mostly involved individual groups of fossils (e.g., trace fossils, Chaplin, 1980; crinoids. Lane and DuBar, 1983) or general stratigraphy (Sable and Dever, 1990). This study focuses on taphonomic analysis, paleocommunity reconstruction, and biological interactions within the paleocommunities. A comprehensive paleoenvironmental analysis is made based on combined paleoecological data, lithological studies, and facies analysis. The reason that the Nada Member was chosen as the focus of this research is two fold. Firstly, there are well-exposed Nada sections in eastern Kentucky that are fairly fossiliferous. Secondly, the Edwardsville Formation in southern Indiana was environmentally equivalent to the Nada Member. Detailed paleocommunity studies have been carried out in the Edwardsville (Ausich et al., 1979; Ausich, 1983). Therefore, paleocommunity study in the Nada, coupled with the previous works in the Edwardsville, can reveal the temporal changes of the Borden delta platform communities. In addition to the paleoenvironmental aspect of the project, a comparative study is made between paleocommunities from the Nada Member of northeastern Kentucky and those from the Edwardsville Formation from southern Indiana. Both the Nada Member and the Edwardsville Formation are interpreted as delta platform deposits of the Borden Delta with one being located in the east and the other being located to the west as a result of the delta progradation. The Edwardsville paleocommunities have been studied in great detail (Ausich et al., 1979; Ausich, 1983). Because the Edwardsville Formation in southern Indiana and the Nada Member in northeastern Kentucky represent the same deltaic environment occurring at different times, comparative study between them sheds new light on long-term community development processes.

1.1. History and Geological Setting of the Borden Delta During Devonian and Mississippian time, a series of deltas gradually filled in large, shallow marine basins in the eastern interior of the United States. The first delta was the Devonian Catskill delta in the northeast, followed by the Devonian to Mississippian Bedford-Berea delta in Ohio, and the Mississippian Borden delta in Indiana, Illinois, and Kentucky. The Borden delta changes into the Warsaw Limestone in Illinois and Iowa (Chaplin, 1980). The Borden For nation is a time-transgressive deltaic deposit present throughout the eastern interior of the United States (Fig. 1.1). Equivalent deposits are the Borden Group of Indiana and Illinois, the Cuyahoga and Logan Formations of Ohio, and the upper part of the Price Formation of West Virginia (Lineback, 1969; Ausich et al.. coastline

38W

J 100 200 km

Figure 1.1. Progradation of the Mississippian Borden Delta. Deltaic deposits are represented as a series of lobate areas and by standard symbols for swampy areas. Modem USA state boundaries and latitudinal and longitudinal positions are provided for reference (after Kepferle, 1977). 1979; Chaplin, 1980,1982; Matchen and Kammer, 1994). Stockdale (1939) provided the first comprehensive stratigraphie treatment of the Borden Group, although it is not entirely consistent with the deltaic model now applied to the Borden. The time-transgressive nature of the Borden Group was first recognized by Swarm et al. (1965) through extensive subsurface studies of the Illinois basin. Since then, various authors have worked on the Borden deltaic system and confirmed the deltaic nature of the Borden deposits (Kepferle, 1977; Chaplin, 1980; Sable and Dever, 1990). Current understanding of the Borden delta is that it was initiated in West Virginia during Kinderhookian time and ended on the western side of the Illinois basin during early Meramecian time. In West Virginia, the Price Formation represents a relatively completely preserved deltaic succession (Bjerstedt and Kammer, 1988). It includes deposits of the outer shelf, prodelta, distributary channels, and coastal plains. Most of the Upper Price Member is of Kinderhookian age. On the western side of the Appalachian basin, in northeastern Kentucky, the Borden Formation consists of the Henley Bed, Farmers Member, Nancy Member, Cowbell Member, Nada Member and Renfiro Member (Fig. 1.4), which include basin-floor deposits, distal turbidites, the prodelta, delta front, and delta platform deposits, respectively (in ascending order). The Borden Formation has been interpreted as the distal equivalent of the Price delta in West Virginia; the time-transgressive nature of these deposits is well displayed from Caldwell, West Virginia, to Morehead, Kentucky (Matchen and Kammer, 1994). In northern Kentucky and Indiana, the Borden Group consists of the New Providence Shale, Spickert Knob Formation (formerly known as the Locust Point and Carwood Formations), and the Edwardsville Formation in ascending order, representing prodelta, delta front, and delta platform deposits, respectively. Community paleoecology studies have been completed for these different subenvironments of the O Morehead

Mt. Sterling w est Liberty

Frenchburg

1. Mile Post 149 Section 2. Mile Post 146 Section 3. Leatherwood Section 4. Hill Top Church Section 5. Frenchburg West Section 6. Frenchburg East Section 7. Hwy 460 West Section 8. Hwy 460 East Section

Figure 1.2 Locality map of the Nada Member sections in eastern Kentucky; locality descriptions are in Appendix D. Borden delta in northern Kentucky and southern Indiana (Lane, 1973; Ausich et ai., 1979; Ausich, 1983; Kammer, 1983). Farther to the west in Illinois, the Borden deposits are largely not exposed at the surface but have been studied extensively in the subsurface. The Borden Siltstone in that region filled the Illinois basin from the southeastern side; in its westernmost extension (northern and northwestern Illinois basin) it is known as the Warsaw Formation. The study area is in the vicinity of Morehead, northeastern Kentucky. Most of the studied sections are in Rowan, Bath and Meniffee counties (Fig.1.2). This area is on the western border of the preexisting Appalachian basin and approximately 140 km east of the axis of the Cincinnati Arch. The outcrop pattern of the Borden Formation is controlled locally by a regional dip of 6 to II m/km eastward from the Cincinnati Arch; it forms a narrow northeast-south west-trending strip across Kentucky (Chaplin, 1980). The Borden Deltaic system developed after a small sea level rise in the very Late Devonian. All of the major fluvial systems that existed during the Late Devonian (represented today by the Catskill Formation and Hampshire Formation) draining the Acadian Mountains were strongly rejuvenated, creating large amount of sediments and causing the great deltaic complexes to prograde once again westward (Kepferle, 1977; Craig and Vames, 1978). Early during Osagean time in southwestern Ohio and east-central Kentucky, prodelta turbidites (the Farmers Member) began to be deposited over Kinderhookian dark shales (Sunbory Shale). They were followed by the delta slope, delta front deposits, and delta platform deposits (the Nancy, Cowbell, and Nada Members), thus completing a deltaic sequence (Chaplin, 1980; Sable and Dever, 1990). The Borden deposits here are correlative with, and grade eastward into, the Pocono Formation in Pennsylvania and the Price Formation in West Virginia. Therefore, the Borden delta system started at the western margin of the Appalachian Basin and prograded all the way across the minois basin, and it represents the last phase of the Acadian orogeny (Frazier and Schwimmer, 1987).

1.2 Geology and Paleoecology of Delta Platform Deposits Since the time when Gilbert (1885) did the classic work on Pleistocene delatic facies in Lake Bonneville, Utah, research on delta systems has advanced greatly. Nevertheless, the three-part Gilbert model of beds (topset, foreset, and bottomset beds) proposed by Barrel (1912) during his work on the Devonian Catskill delta deposits still has a lot of influence on both ancient and modem delta research, and commonly occurs in much of the recent literature in slightly modified form.

The study of modem deltas commenced with the Mississippi delta; The Mississippi is still considered a classic example of a deltaic model (Miall, 1984). Since then, many other modem deltas around the world, such as the Rhone, Niger, Danube, Nile, have been studied because they are important for understanding petroleum deposits. The generally accepted deltaic classification scheme recognizes the continuity of delta types in nature and defines three end-member types; i.e.: (1) fluvial-dominated deltas; (2) wave-dominated deltas; and (3) tide-dominated deltas (Fig. 1.3). The Mississippian Borden delta is considered to be mainly a fluvial-dominated system (Kepferle, 1979). Generally speaking, all deltaic depositional systems represent a coarsening-upward succession, with fine-grained bottomset (prodelta) beds that are the background basinal sedimentation, punctuated by turbidites, followed by foreset (delta front) siltstone and sandstone beds, capped by topset (delta platform) sandstone beds. During the course of deltaic progradation, these facies become vertically stacked from deep- to shallow-water facies. However, every delta system has its own architecture that may deviate from this simplified view, due to factors such as sediment supply or basin tectonics. RIVER ENERGY

Mississippi

FLUVIAL DOMINATED Danube

Nüe

WAVE Mekong TIDE DOMINATED DOMINATED Rhone Ganges \ Klang-Langat

WAVE ENERGY TIDE ENERGY

Figure 1.3. Classification of deltas according to predominant processes of formation; characteristic rivers are indicated (after Miall, 1984). Among the three components of the delta system, the delta platform (topset) is the most diverse environment because of its close interaction between the subaerial fluvial and the subaqueous marine systems. It can generally be divided into two parts, the distal part of the platform that is adjacent to the delta slope where the marine regime predominates, and the proximal part of the platform that is next to the river mouth where the fresh water fluvial system merges with sea water to form a very complex environment. The distal part of the delta platform usually provides habitats for normal marine organisms, whereas the more proximal part of the platform might host mostly brackish-water organisms that can tolerate a very wide range of salinity and energy levels. Sedimentologically speaking, the proximal part is characterized by constantly shifting fluvial distributary channels. Sands and silts are the dominant sediments in the channels, whereas finer sediments are usually in the interdistributary areas where a variety of flood-generated processes occur. The Nada Member of the Borden Formation in northeastern Kentucky contains an exclusively marine fauna, and the sediments contain a great deal of glauconite (See Chapter 2 for detailed discussion). Therefore, the Nada Member fits into the distal part of the delta platform that is very similar to a normal marine shelf environment

1.3. Introduction to the Borden Delta Deposits in Northeastern Kentucky The Borden Formation in northeastern Kentucky consists of the following six members in ascending order: the Henley Bed, Farmers Member, Nancy Member, Cowbell Member, Nada Member, and Renfro Member (Fig. 1.4). It is generally a coarsening- upward succession (with the exception of the turbidites in the Farmers Member) of terrigenous clastic rocks. Underlying the Borden Formation is the Sunbury Shale, which is composed of basin-floor deposits. Overlying formations are the Newman Limestone and then the Breathitt Formation. In northeastem Kentucky, the average thickness of the Borden Formation is 204 m, and the maximum thickness is approximately 274 m (Chaplin, (8 I PROBABLE UNIT 1 Z ENVIRON­ GENERAL CHARACTTERISTIC^ MENTS 1i E- Limestone, finely to moderately Upper 0-38 Near-shore crystalline, cherty, oolitic Member with abundant megafossils

Ste. Limestone, moderate to coarsely Carbonate 1 Genevieve 0-30 crystalline, sandy, oolitic, often shoal I Ls. Mbr. crossbedded; fossils rare

St. Louis Shallow Limestone, micritic, cherty, 0-7 Z Limestone subtidal silicified megafossils common 1 Mbr. High Dolomite and dolomitic limestone, z 0-6 intertidal yellowish-tan, fossils rare < Renfro Mbr. Q_ ? Œ. CO Delta Greenish gray shale with layers of CO Nada Mbr. 0-26 platform glauconitic siltstone and carbonates CO CO 26- Massive siltstone, locally containing s 1 Cowbell 116 Delta front shale interval; trace fossils common 0 Mbn ^ 18- Gray shale, bioturbated; abundant ^ ^ancy Prodelta cephalopods in the sideritic nodules i M b r^ 125 0.3- Fine-grained sandstone, with Turbidites ? Farmers 82 mudstone intercalations Mbr. Greenish-gray mudstone, pyritic, —'■'^""^^enl^ 0.9 Basin floor structureless Bed -9 1.5- Sunbury Basin floor Black shale, fissile, pyritic; Shale 8 fossils common

Berea _ Light ray sandstone, fine­ 0-30 Delta front Ss grained —? — Bedford Fm. 0-27 Prodelta Gray, pyritic sandstones Ohio 41- Black, fissile, pyritic shale, Basin floor Shale 76 with some carbonate concretions

Figure 1.4. Borden Formation and other deposits in eastern Kentucky (after Chaplin, 1980).

10 1980). The sequence generally becomes thinner to the west. Previous studies indicate a general westward direction of paleocurrents (Sable and Dever, 1990). Starting from the bottom, the Henley Bed consists mainly of grayish-green, greenish-gray, structureless siliciciastic mudstones with thin layers of intercalated turbidite- like siltstones. Pyrite or marcasite crystals and nodules occur throughout the unit. Flute casts and load casts are present in some horizons (Potter et al., 1991). Locally, a dark gray, spore-bearing layer occurs in the lower part of the Henley. The average thickness of the Henley is 3 to 4.5 m, and it contains very few macrofossils. However, microfossils such as conodonts, spores, and arenaceous foraminiferans are very abundant. From the conodonts that have been recovered, the Henley is interpreted to encompass several conodont zones and overlap the Kinderhookian-Osagean boundary (Chaplin, 1982). Considering its small thickness and relatively long duration, the Henley Bed represents an extremely slow sedimentation rate in the deepest part of the basin-floor environment. The environment was dominated by hemipelagic accumulation of muds, and was frequently interrupted by the rapid influx of turbidite flows that carried very fine­ grained sands and silty muds (Chaplin, 1980). The Farmers Member consists of a monotonous succession of alternating tabular- bedded allochthonous sandstone-siltstones and autochthonous mudstones-shales. Sandstone beds, commonly 15 to 20 cm thick, are interbedded with mudstones commonly 5 to 15 cm thick. Turbidite beds with Tb-Te and Tc-Te Bouma divisions are common. Sole marks (scour marks, tool marks, etc.) are common. Abundant trace fossils, which belong to theNereites ichnofacies of Seilacher (1967), representing a relatively deep water environment, are present The lack of Ta and Tb divisions, and the trace fossil associations combined with sedimentary stmctiues, indicate distal turbidite deposits (Chaplin, 1980; Sable and Dever, 1990).

11 The Nancy Member consists dominantly of bluish- to greenish-gray silty shale. The shale ranges from slightly silty in the lower part to very silty in the upper part. The member is highly bioturbated, especially in its shaly portions in the lower part, where intense bioturbation has homogenized the beds and destroyed the sedimentary structures. Parallel, lenticular and ripple laminations ere common in siltstones near the top of the unit The Nancy Member contains abundant sideritic nodules that are very fossiliferous. Brachiopods, cephalopods, gastropods, and conulariids are the most common macrofauna. Trace fossils are abundant but non-diverse, and generally belonging to the Zoophycos ichnofacies. These features are generally comparable to those on the lower part of the delta front of the modem Mississippi delta, and thus, the whole Nancy Member is considered to have been deposited in a prodelta envirorunent (Chaplin, 1980; Sable and Dever, 1990). The Cowbell Member is composed mainly of bluish-gray to yellowish-gray siltstones interbedded with very fine-grained sandstones and sUty shales. Sedimentary structures are well preserved, and include crossbedding, parallel laminations, current ripple marks, ripple-drift laminations, lenticular laminations, scour and fill structures, penecontemporaneous slump structures, and rip-up clasts. Among the trace fossils, vertical burrows become increasingly common toward the top of the member, and vertical escape structures are very common (Chaplin, 1980; Sable and Dever, 1990). The Nada Member, which is the focus of this dissertation, is highly variable in its lithological characteristics and stratigraphie thickness. It consists mainly of dark-red, greenish-gray, and grayish-purple siliciciastic mudstones and shales with thin, intercalated beds, lenses, and pods of sandy, glauconite-streaked, bioturbated siltstones. Locally, it may contain discontinuous beds and lenses of glauconite-streaked, crossbedded, ripple- marked crinoidal wackestones, packstones,and grainstones. Glauconite grains and pellets occur throughout the Nada. In addition, phosphate nodules are also present in the Nada. Macrofossils are abundant in the Nada, particularly in the carbonate lenses, and include

12 crinoids, bryozoans, brachiopods, corals, gastropods, trilobites, conulariids, pelecypods, and cephalopods. The combination of the sedimentary structures, faunal composition, and lithologie features in the Nada indicates that it represents the subaqueous portion of a delta platform and probably marks the beginning of delta abandonment arising firom marine transgression (Chaplin, 1990; Lane and DuBar, 1983; Sable and Dever, 1990). A unique lithological feature of the Nada is the drastic reduction of its siliciciastic components, the large amount of glauconites and phosphates present, and the presence of carbonate stringers.

1.4 Research Methods Applied Because of the preservational condition of the fossils and the outcrops of the Nada Member, the standard paleoecological methods involving individual fossil counting (Dodd and Stanton, 1981) are not applicable. Instead, regular systematic collecting was used to get as many fossils as possible from every horizon and from float deposits. Few fossils were found on the fresh rock. Most fossil sites are road-cuts. Many nicely preserved fossils were found in float rock. Because the Nada Member is not a thick lithological unit, and because it displays a clear lithological gradation, the general collection turns out to be very representative and consistent. A total of 14 fossil sites have been examined, and among them, eight relatively complete sections were systematically collected (Fig.1.2). During field collecting, special attention was given to the taphonomic conditions that were associated with the fossil assemblages. Lithologie and micropaleontologic samples were systematically collected from four sections that were measured and described. Lithologie samples were thin- sectioned and examined under a pétrographie microscope. Both the lithologie and faunal data from the thin-sections were used for microfacies and environmental analysis.The classification scheme for carbonate rocks is a combination of Folk (1962), Dunham

13 (1962), Zuffa (1980), and Mount (1985). Microfossil samples (mostly calcareous shales) were broken into small pieces and then dissolved in acetone solvent Microfossils were picked, examined, and identified.

Most fossils were identified to the generic level. Crinoids and brachiopods along with other groups were identified to the species level. Bryozoans were identified into family or even higher taxonomic levels.

14 CHAPTER 2

BIOSTRATIGRAPHY. SEDIMENTOLOGY, AND THE BORDEN DELTA PROGRADATION

2.1 Facies Analysis and Sedimentology The Nada Member of the Borden Formation in northeastern Kentucky is the topmost part of the Borden delta and represents the distal portion of the delta platform facies (Chaplin, 1980; Sable and Dever, 1990). The lithoiogy and the thickness of the Nada is variable from section to section, probably as a result of the extremely variable depositional conditions existing in the delta platform environment. Nevertheless, the dominant lithoiogy is greenish siliciciastic mudstone and shale. The unit below the Nada is the Cowbell Member. The Cowbell is mainly a siltstone unit, and interpreted as a delta front deposit. The boundary between the two units is gradational. However, the upper boundary of the Nada is typically very sharp. In most of the studied sections, the overlying unit is the Renfro Member. The Renfro Member is mainly argillaceous dolomites, and commonly is cliff forming. Lithologically, the Nada Member is mainly composed of greenish, greenish-gray, and dark-purplish siliciciastic mudstones and shales, intercalated with carbonate lenses and siltstone beds. The most conspicuous compositional feature of the Nada is the common occurrence of glauconite and phosphadc nodules, especially in the upper part This

15 indicates a possible transgression that started the abandonment phase of the Borden delta in this region (see Section 2.2 of this chapter). Sedimentary structures are rarely present in the siliciciastic mudstone and shale beds, but in the siltstone and carbonate beds, current ripple marks and low-angle crossbedding are common structures. Trace fossils are very abundant and are in almost every siltstone bed. They belong to \i\&Cruziana ichnofacies, which represents a relatively shallow marine environment (Chaplin, 1980). Thin section studies reveal a variety of microfacies of the carbonate lenses (see later discussion). The paleontological composition of allochems is very similar in all the microfacies, but the lithologies vary from wackestone through packstone and grainstone according to Dunham's (1962) classifrcation. Most of the fossil allochems include crinoid stems, brachiopods, bryozoans, and pelecypods. Glauconite grains have a pelloidal morphology and fill many bryozoan zooecia. They are probably formed from the replacement of the original pelletai materials. Phosphate grains were also observed in the thin sections as interstitial fillings. The Nada Member can be subdivided into two parts in the study area. The lower part of the Nada is characterized by interbedded greenish siliciciastic mudstones, carbonate stringers, and shaly siltstones. The upper part is characterized by 2- to 4 m-thick, purplish to greenish, structureless shales or siliciciastic mudstones. Virtually no fossils occur in this unit except for a few fossils inside the phosphatic nodules at the top of this unit The boundary between individual siltstone and mudstone beds is very gradational, but the limestone lenses tend to have a sharp, scoured base.

Based on the lithologie, ichnologic, and paléontologie data, two facies can be established, namely, the skeletal tempestite facies of the carbonate stringers and the interdistributary facies (interdeltaic bay facies by Chaplin, 1980) of the siliciciastic mudstone.

16 2.1.1 Jnterdistributary Mudstone Facies of the Distal Delta Platform This is the dominant lithologie facies in the Nada as defined by Elliot (1986) in his delta platform facies model. It is generally a quiet, shallow water environment, although locally generated wind-waves may induce mild stirring and produce some ripple forms and lenticular laminae. Its lithologie composition and structure are controlled both by terrigenous source area and by the local water chemistry, energy, and biological conditions. The lithologies of this facies consist of greenish-gray siliciciastic mudstones interbedded with shaly siltstones. Because of difierendal weathering, the resistant siltstone beds are prominant on outcrops (Fig.2.1). The siliciciastic mudstones display poor lamination or bedding. The siltstones are usually thin- to medium-bedded (8-15cm), and laterally extensive. They are highly gradational with the siliciciastic mudstones. Current ripple marks occur sometimes on the upper surface of the siltstone beds. Mudstone Subfacies The siliciciastic mudstone beds are mostly structureless, with very low fissility. Dissolved samples yield microskeletal materials. Spectacularly preserved complete crinoid fossils are sometimes found in this facies, indicating relatively quiet water conditions. Macrofossils are fairly common in this facies. They include bryozoans, corals, crinoids, brachiopods, gastropods, and pelecypods. Compared with the siltstone beds where tracp. fossils are common, far fewer trace fossils occur in the mudstone. Apparently, the siliciciastic mudstone facies supported primarily epifaunal organisms, whereas the siltstone facies mostly supported infaunal organisms. Sediment supply for the detrital components in the Borden is thought to be from metamorphic and felsic plutonic rocks. Possible source areas were either in or east of the present Piedmont belt, or the New England Acadian systems (Sable and Dever, 1990). Deposition of the interdistributary facies appears to be from the interaction between continuous feeding of sediments out of the Appalachians

17 Siltstone interbeds

m

Figure 2.1. Differentiating weathering o f the mudstone facies with siltstone interbeds.Siltstones are more resistant to weathering and they stick out in the field.

1 8 through river sytems that existed in this region and occasional storm events. Based on the observations that no plants or other terrestrial fossils were found in the Nada and that all the fossils were representative of normal, shallow marine settings, the Nada appears to represent the very distal part of the Borden delta platform. It was not drastically influenced by the fluvial depositonal regime in terms of water chemistry and energy. Siltstone Subfacies Thin-sections of the siltstones reveal that the major components of the siltstone are quartz grains (mostly silt-sized), interstitial clays, and calcite cements that appear to have resulted from the dissolution and reprecipitation of skeletal material during diagenesis. Some fossil fragments can be found occasionally. Glauconites can be locally concentrated in some thin-sections, and most glaoconite is granular and displays a typical pelloidal morphology. There are two types of siltstone beds in the Nada. The first type of siltstone bed is highly gradational with the siliciciastic mudstones and shales below and above. It was probably deposited under sedimentological conditions similar to the mudstones except for fluctuations in turbulence or some minor changes in source area. The second type of siltstone bed is very extensive laterally, and has sharp boundaries with the mudstones. Some scour surfaces are present at the bases of these beds. This type of siltstone is probably a result of storm deposition. The siltstone beds in the Nada Member are rich in trace fossils including the following 13 ichnogenera (Chaplin, 1980):Arthrophycus, Cruziana, Cylindrichnus, Helminthoida, Lophoctenium, Monocrdterion, Palaeophycus, Phycosiphon, Planolites, Psammichnites, Scalarituba, Teichinchnus, and T^ophycos. They represent a variety of animal behaviors, including resting, feeding, crawling, grazing, and dwelling. Although the trace-makers are not easily identified in most cases, we infer that Psammichnites represents crawling trails of gastropods;Phycosiphon represents feeding traces of worms;

19 Cruziana represents trilobite trails; Arthrophycus, Phycosiphon, and Teichinchnus are feeding traces; Cylindrichnus and Lophocterium are resting traces; Helminthoidea, Scalarituba, and Zoophycos are grazing traces; Monocraterion is a dwelling trace; and Planolites and Psammichites are crawling traces. Trace fossils are good indicators of depositional environment in paleoenvironmental studies because they are in situ, thus representing the original sedimentary environment One of the earliest ideas concerning ichnoiogy is that trace fossils are bathymetrically sensitive and different trace fossil assemblages are representative of different depositional facies. Seilacher (1967) was the first to systematize this concept by putting forward the well-known ichnofacies schemes that were expanded and elaborated by later workers (Rhoads, 1975, Chamberlain, 1979; Bromley, 1990; Pemberton et al., 1992). Seilacher (1967) described six inchnofacies representing a continuous bathymetric zonation of trace fossils: the bathyal-abyssal Nereites facies; the intermediate shelf Zoophycos facies; the shallow water Cruziana faciesm the intetûdalSkolithos facies, the supratidal facies, Glossifungites facies, and the non-marine Scoyenia facies. The Nada Member of the Borden Formation displays a high abundance and low diversity of trace fossil assemblages. Grazing traces, resting traces, crawling traces, horizontal and vertical burrows are common in the shaly siltstones. Chaplin (1982) correlated this trace fossil assemblage with the Cruziana ichnofacies, which is the shallowest marine facies. This ichnofacies is supposedly dominated by abundant dwelling and resting traces. The shallow water ichnofacies designation is consistent with the delta platform interpretation of the Nada Member, which is based primarily on sedimentology and stratigraphy. Chaplin (1980) recognized two types ofZoophycos in his study o f the trace fossils of the Borden Formation in eastern Kentucy. Type I is helicoidal, and type 2 is planar. Results of this study indicate that this distinction is probably not so clear-cut. The helicoidal forms are more common in the siltstones, whereas the planar ones are more common in siliciciastic mudstones. Therefore, the

20 morphological differences could very well be a result of compaction, lithification, and other diagenetic processes.

2.1.2. Carbonate stringer/;empestite facies Although carbonates are not the dominant lithoiogy in the Nada Member, they occupy a key position in the paleoenviromental interpretation of the unit because they are the most fossiliferous beds and they are the transition between the siliciciastic and the carbonate systems that existed in the Borden Delta platform environment. The carbonate lithoiogy in the Nada mostly exists as crinoidal skeletal lenses, stringers, or discontinous beds interbedded within the interdistributary siliciciastic mudstone facies. Petrographically, they are primarily impure carbonates, containing fairly large amounts of siliciciastic materials (silts and clays). The major framework bioclasts include crinoid columnals, bryozoans, and brachiopods. In addition, a great deal of glauconites are present. With the presence of various amounts of detrital materials (usually >5%) in these carbonates, neither Folk's (1962) nor Dunham's (1962) classification scheme seems to be applicable except for rare cases. The traditionally dichotomy of siliciciastic versus carbonate that has been reinforced in almost every sedimentary petrology textbook apparently overlooked the mixed siliciciastic and carbonate sedimentological environments which, against the common myth about their rarity, are actually fairly common both in modem and ancient depositional systems (Mcllreath and Ginsburg, 1982; Doyle and Roberts, 1983; Mount, 1984). Below a discussion is given for the classification schemes of Zuffa (1980) and Mount (1985). However, although inappropriate, a Dunham name for these rocks would be wackestones and packstones. Two classification schemes for mixed siliciciastic and carbontate sediments are presently available. One was proposed by Zuffa (1980) who used the term "hybrid arenitites" to designate this group of sedimentary rocks. His classification scheme

21 emphasized the significance of distinguishing between extrabasinal and introbasinal detritus. Five main groups of arenaceous grain types are recognized; 1), NCE (noncarbonate extrabasinal (typical framework grains of a sandstone); 2), CE (carbonate extrabasinal (limestones, dolostones, etc.); 3), NCI (noncarbonate intrabasinal (glauconite, phosphate, iron-oxides, etc.); 4), Cl (carbonate intrabasinal (typical firamework grains of a limestone); 5), V (volcanics, both extrabasinal and intrabasinal). This scheme relates arenaceous grains with their origins, thus providing a better understanding of the processes that were involved in the formation of a specific texture. However, it ignores the mud- dominant types of sediment Also the identification of extrabasinal versus intrabasinal carbonate grains could be difficult. Mount (1985) presented a different classification scheme that he named a first-order textural and compositional classification. His scheme emphasized the necessity of objectivity and precision of a classification system that should not be controlled by the interpretation of the origin of the rock. The conciseness and clarity of his scheme make it easy to use, but it overlooks the grain types such as glauconite whose general environmental implication is already well clarified. In addition, it does not include the silt-sized sediments probably because that will make his classification diagram too complicated. A combined approach that incorporates Zuffa's, Mount's and Folk's classification schemes is applied in the current study in an attempt to make the best use of all the available information. The carbonate lenses in the Nada Member have a range of mixed siliciciastic and carbonate materials. Because the origins of most of the components in the Nada are reasonably certain, a grain component analysis according to Zuffa's scheme is possible and it is compiled in Table 2.1:

22 NCE: quartz, clay minerals. CE: does not exist in any meaningful amount. NCI: glauconite, phosphate, iron-oxides. Cl: various fossil skeletals including bryozoans, brachiopods, echinoderms, pelecypods, corals; and some interstitial calcite that is probably resulted from the early diagenetic dissolution of the skeletals. V: no detectable amount present.

Table 2.1. Grains types of the Nada Member carbonates (according to Zu^a's (1981) scheme)

23 Combining these grain Qrpes with Mount's (1985) and Folk's (1962) classification schemes, four microfacies are recognized in Table 2.2.

1). Phosphatic allochemic mudstone; Clay-sized minerals are the major matrix with minor quartz silts and phosphate grains; large skeletal fragments can be seen occasionally. This microfacies is related to type 1 carbonate. 2). Glauconitic allochemic siltstone: Silt-sized quartz makes almost the whole texture of the rock, with minor to major glauconites (20-40%); cal :ite skeletals can be seen occasionally. This microfacies is related to type 1 carbonate. 3). glauconitic and phosphatic silty packed biomicrite skeletal allochems >50%, with silts, glauconites, and phosphates as matrix. This microfacis is related to type 2 csubonate. 4).Glauconitic biosparite This microfacies occur in both types of carbonate.

Table 2.2. Microfacies in the Nada carbonates

These microfacies did not display any paleogeographic zonation. Nevertheless, they are present in most of the studied sections where the lower part of the Nada was exposed. The lateral and vertical changes of these microfacies are very frequent within even meters of distance. This probably indicates a large amount of variability in water conditions. Carbonate bedding in the Nada Member displays two types of occurrence. The first and dominant type typically has a sharp base that commonly truncates the imderlying lithoiogy (mostly siliciciastic mudstones) and displays a typically rugged scouring surface. This type of structure has been termed "pot cast" (Aigner and Futterer, 1978) or "gutter cast" (Whitaker, 1973; Aigner, 1979) and is typically associated with storm deposits (Kreisa, 1981). Carbonate beds of this type have a slightly grayish color in the field, which makes them distinct from the surrounding greenish shales. Thickness of the beds is highly

24 variable; the beds commonly pinch out laterally. Large skeletal material (crinoid columnals, bryozoans, brachiopods, and gastropods) form the fiiamework of the rock that is filled with interstitial silt-size sediments or clay minerals. Glauconites can be extremely concentrated in some horizons. The original voids produced under the shelter of the large skeletals are filled with finer sediments. These infiltration fabrics suggest that the large skeletal grains supported the fabric of the rock prior to deposition of some of the finer sediments (Kreisa, 1981).

Kreisa (1981) proposed a storm deposit model based on his study of the Ordovician Martinsburg Formation, southwestern Virginia. Based on original and previous studies. He developed a list of the sedimentary structures that are normally associated with storm deposits. Most of those listed features were found in the Nada (see discussion below). The first type of the carbonates in the Nada, therefore, represents a below-fair-weather-wave- base shelf environment where background low turbulence conditions were periodically interrupted by storm events. These storms concentrated skeletal material on the sea floor and probably exhumed previously buried shells. Winnowing and suspension of the finer sediments by the storm turbulence resulted in a fossil lag deposit. The frequent occurrence of the infiltration fabrics in the Nada also indicates alternating high and low energy conditions. In addition to the lenticular nature of these beds, the Nada has the following characteristics that are indicative of storm deposits rather than turbidites: sharp base, pot- and gutter- cast at the bottom instead of aligned tool marks, and ungraded skeletal lag (Kreisa, 1981; Kreisa and Bambach, 1982; Einsele and Seilacher, 1991). Previous studies show that most open-shelf storm deposits contain autochthonous or parautochthonous faunas. Extensive transportation and mixing of fauna is probably restricted to near-strandline environments where powerful onshore and offshore currents may entrain large shells (Aigner, 1982; Seilacher and Aigner, 1991; Ausich and Sevastopulo, 1994). This probably explains why the faunal composition in the Nada

25 carbonates is essentially the same as in the siliciciastic mudstone facies. Therefore, the Nada fauna as a whole is considered authochthonous and represents the original fauna living on the Borden delta platform. Individual fossil occurrences in the Nada should be considered parauthochthonous.

Variability in storm deposits is interpreted to be related to paleobathymetry. In general, shaUow-water storm deposits are thick, amalgamated, and display evidence of powerful currents such as matrix-free lamination and hummocky cross stratification. On the other hand, deeper water storm deposits are thin-layered and have less scouring and more matrix (Kreisa, 1981). The presence of a large amount of finer matrix material and the absence of the hummocky stratification in the Nada suggest a deeper-water setting. The second type of carbonate deposit in the Nada Member is characterized in field by having a gradational and interfingering relationship with the surrounding siliciciastic mudstones. The carbonates lack sharp bases at their bottom and have thickness of 30 to 40 cm. They appear to be carbonate masses as defined by Wilson (1975) that resulted from the piling of crinoids, brachiopods, and bryozoans. The lack of silts and muds is probably due to the densely populated crinoids and bryozoans that restricted siliciciastic influx. These carbonate masses are very restricted in lateral extent. The reason for this is probably the patchiness of the original faunal distribution. The formation of mixed siliciciastic and carbonate material involves a number of biologic and sedimentologic processes. Based on the examination of 150 modem and ancient examples of mixed sediments on both open and rimmed shelves. Mount (1984) proposed four basic mixing processes: 1) punctuated mixing-transfer of sediment between contrasting depositional environments during high intensity sedimentation events such as storms; 2) facies mixing—mixing of sediments occurs along interface between nearshore siliciciastic belt-tidal flat facies and offshore carbonates; 3) in situ mixing—mixing occurs through the autochthonous generation of carbonate material within siliciciastic sediments;

26 and 4) source mixing—mixing occurs in marginal marine and nearshore environments that are proximal to exposed carbonate source terranes. The mixed carbonate facies in the Nada fall into the punctuated mixing type, which is characterized by storm deposits, and the in situ mixing type, which fits into the facies of carbonate masses.

2.2. Phosphates and glauconites in the Nada Member and their paleoenvironmental implications In the shallow marine environment, the most characteristic authigenic minerals are various iron silicates, such as glauconite and chamosite, and some phosphates. Phosphatic nodules also characterize horizons of slow or no deposition in shallow marine clastic deposits (Johnson and Baldwin, 1986). Phosphates are particularly characteristic of areas of slow siliciciastic sedimentation, frequently occurring on topograpliic highs and in areas of coastal upwelling (Lucas and Prevot, 1991). Glauconite is restricted to the marine environment, forming mainly by the alteration of organic matter, particularly fecal pellets. Glauconites accumulate mainly by the transport and deposition of granules and pellets with other siliciciastic material and is a common constituent of shallow marine “greensands” (Johnson and Baldwin, 1986). Hardgrounds in calcareous successions, which are known from rocks as old as Cambrian, commonly include crusts or nodules formed by glauconite and phosphate mineralization. Fossilization in the nodules takes a range of forms: calcareous tests preserved in a phosphatic matrix; internal molds due to infilling of chambers with phosphatic mud or epigenic phosphatization of the skeleton itself. Several hypotheses have been proposed to explain the formation of these phosphate nodules. Kennedy and Garrison (1975) thought that mineralization occurred in the sediment while “omission surfaces” were exposed for long periods during times of low rates of sedimentation. In the Cretaceous of

27 southern England, nodules that were originally calcareous were altered to glauconite and then phosphatized. Internal molds, together with some residual skeletons, were secondarily phosphatized by phosphorus supplied by circulating seawater. Glauconites exist throughout the Nada Member. Microscopically, all the glauconite grains are apparently fecal pellets, which are the most common origin of glauconite grains (Johnson and Baldwin, 1986). In most cases the phosphates in the Nada Member exist as phosphatic nodules. They are particularly conspicous at the bottom of the Nada, especially in the transitional beds from the Cowbell siltstone to Nada silty mudstones. In the upper part of Nada they are present at the contact between the Renfro dolostones and the Nada shales. The phosphatic horizons seemingly represent ancient hardgrounds that were covered with phosphatic nodules and glauconites. One of the most fascinating aspects of the Nada is that phosphatic nodules often contain fossils. Generally, the calcareous shells of organisms have been preserved in a phosphatic matrix. From a taphonomic point of view, all the fossils inside the phosphatic nodules were preserved with details of test structures. It probably indicates that skeletons of fossils were not transported or distributed much by the water current. Therefore, these fossils were, by and large, in situ remains of ancient organisms. Both glauconites and phosphatic nodules represent slow or no depostion in shallow marine siliciciastic deposits. This further confirms the thinking that the Nada Member was the very distal portion of delta platform deposits and very little terrestrial materials reached this portion of the delta platform. The abundant presence of glauconites and phosphates indicates that the Nada Member represents a period of transgression and the abandonment of the Borden delta.

2.3. Faunal Analysis and Biostratigraphy

28 In northeastern Kentucky, the rocks that comprise the Borden delta are collectively named the Borden Formation. Depositionally it is analogous to the Cuyahoga and Logan Formations of Ohio, the Borden Group of Indiana, and the Price Formation of West Virginia (Sable and Dever, 1990). The average thickness of the Borden Formation is approximately 204 m and maximum thickness is approximately 274 m. Henley Bed, the lowest member of Borden, consists mainly of grayish-green to greenish-gray siliciciastic mudstones with thin interbeds of siltstones and very fine sandstones. It is interpreted as the basinal deposits. A microfauna (conodonts) fix>m the Henley Bed indicates a Kinderhookian age (Chaplin, 1980). The Farmers Member of the Borden Formation is composed of tabular-bedded sandstones and siltstones with interbeds of mudstone. It was interpreted as a turbidite sequence (Kepferle, 1977). Fossils are rare in Farmers Member. The Nancy Member of the Borden has the lithoiogy of grayish-green shales with interbeds of thin-lay<»red siltstones. Numerous sideritic nodules that contain many types of fossils including brachiopods, cephalopods, gastropods, and conulariids occur in the Nancy Member. The cephalopod fauna indicates an early Osagean age (Mason and Chaplin, 1979). The Cowbell Member of the Borden is a highly transitional lithologie unit. It is a massive siltstone unit with interbeds of shale. The lower part of Cowbell is similar to the underlying Nancy Member, whereas the upper part is similar to Nada Member. The Nada fauna includes the following groups: crinoids, brachiopods, rugose and tabulate corals, bryozoans, blastoids, gastropods, pelecypods, cephalopods, conulariids, trilobites, and fish bones. Among these, crinoids, brachiopods, bryozoans, and rugose corals are the most abundant groups (Table 2.3).

29 Crinoids: Rhodocrinites barrisi (Hall) Gilbertsocrinus tuberculosis (Hall) Uperocrinus pyriformis (Shiunard) Uperocrinus acuminatus new species Macrocrinus koninki (Shumard) Eretmocrinus corbulis (Hall) Ereimocrinus calyciüoides (Hall) Aorocrinus nodulus new species Dorycrinus quinquelobus (Hall) Agaricorinus stellatus (Hall) Agaricocrinus builatus Hall Discocrinus protuberatus new genus, new species Blairocrinus sp. Platycrinites glyptus (Hall) Platycrinites planus (Owen and Shumard) Platycrinities tennuibrachinatus Meek and Worthen Platycrinities ?incomptus (White) Synbathocrinus wortheni Hall Halysiocrinus dactylus (Hall) Cyathocrinities iowensis (Owen and Shumard) Atelestocrinus kentuckyensis new species Holcocrinus spinobrachiatus (Hall) Histocrinus sp. Barycrinus sp. Taxocrinus sp. Brachiopods: Lingula sp. Actinoconchus lamellosus (Leveille) Spirifer rowleyi Weller Spirifer latter Swallow

(Table 2.3 continued on next page)

30 (Table 2.3 continued 6om previous page) Marginatia burlingtonensis (Hall) Spinocarinifer sp. Rhytiophora arcuatus (Hall) Echinoconchus sp. Productus sedaliensis Weller Rugosochonetes multicosta Winchell Conulariids: Paraconularia subulata (Hall) Conularia multicostata Meek and Worthen Trilobites: Paladin chesterensis (Weller) Australosutura lodiensis (Meek) Cephalopods: '^Michelinoceras” sp. Subvestinautilus sp. Cnidarians: Amplexizaphrentis sp. Amplexus sp. Cyathaxonia sp. Trochophyllum sp. Cladochonus beecheri (Grabau) Cladochonus crassus (McCoy) Bryozoans: two unidentified species Gastropods: Platyceras (Platyceras) tribulosum White Platyceras (Platyceras) biserialis Hall Platyceras (Platyceras) equilateralis Hall Platyceras (Orthonychia) acutirostra (Hall) Blastoids: Granatocrinus sp.

Table 2.3. List of fossil taxa identified in the Nada Member.

31 Twenty-five species of crinoids are identified from the Nada, and among them, there is one new genus and three new species (see Chapter 5). Most of the species are advanced camerates, but there are also disparids, cladids and flexibles. O f the 25 species, thirteen are species known previously from the upper Burlington Limestone in the type Mississipp'an section area in Iowa, Missouri and Illinois. In particular, the most common crinoid species in the Nada, Uperocrinus pyriformis is a typical and common upper Burlington species. Therefore, the crinoid fauna strongly indicates a middle Osagean age, equivalent to the upper Burlington Limetone (Lane and DuBar, 1983). The brachiopod fauna includes productids, spiriferids, chonetids, strophomenids, and lingulids. Among them, the spiriferids and productids are the dominant groups. Most of the brachiopod species in the Nada are stratigraphically long-ranging except for Marginatia burlingtonensis, which is a common Burlington Limestone species. Both rugose corals and tabulate corals occur in the Nada. No species level designation was given to the rugose corals. The two tabulate coral species are encrusters. They attached to hard substrata including crinoid stems (see Chapter 3). Both species have been reported throughout the Mississippian, thus, they do not provide detailed biostratigraphic information. One of the most interesting fossil groups in the Nada Member is gastropods. Most of the species belong to a imique group of archaeogastropods, namely, the platyceratids, and they are commonly found throughout the Nada. Because of the long-ranging nature of most platyceratid genera and a lack of well-defined species-level systematics, their biostratigraphic application is very limited. There are very few constant and stable morphological features that can be used for their classification. Characteristics that are used to designate the numerous species are so variable and unstable that it is often impossible to clearly distinguish between many of the species, thus resulting in a lot of geologically

32 long-lasting species. An exception to this is the platyceratids with long, tubular spines 6om the Mississippian rocks. They are very good biostratigraphic markers, which is a fact that has generally been overlooked. Spinose platyceratids apparently originated during the Early Devonian. Platyceras dumosum Conrad and P. echinatiim Hall are two representative species of this group. The typical pattern of spines for Devonian platyceratids is randomly scattered spines all over the shell surface (see Chapter 6). When this group evolved into the Mississippian, the distribution of the tubular spines became more and more regular. To date, there are only two described species of spinose platyceratids from the Mississippian, i.e., P. tribulosum White and P. biserialis Hall. Both of them occur in the Nada. They are characterized by regular, longitudinal rows of tubular spines. These species were previously known only from the standard Mississippian type section area of Iowa, Illinois and Missouri, where they occurr in the Burlington Limestone (Hall, 1859; Meek and Worthen, 1868; Keyes, 1889, 1890a, 1890b, 1892; Shimer and Shrock, 1944). In addition to the two spinose species, the other two common Mississippian platyceratids,P. equilaterialis Hall and P. {Orthonychia) acutirostre (Hall), are also present in the current collection. However, they are long-ranging species and, thus, have no significance for detailed biostratigraphic correlation. Judgimg from the entire gastropod fauna, the Nada should be correlated with the Burlington Limestone in the Mississippian type section. Another common group of fossils in the Nada Member is bryozoans. They occur almost in every horizon and are one of the dominant groups. No attempt was made at the specific- level of identification of this group, therefore, no definite stratigraphie designation can be made from them. Two conulariid species were found in the Nadd Member. Conularia multicostata is restricted to the Kinderhookian and Osagean of North America.Paraconulria subulata occurs throughout most of Carboniferous (Babcock and Feldmann, 1986).

33 Trilobites, pelecypods, cephalopods, conodonts, and fish bones are rare in the Nada. Although they play very important role in the paleocommunity structure of the Nada (see Chapter 4 ), they provide very little detailed biostratigraphic information. Conodont samples have been collected and processed. Unfortunately, they are extremely rare in the Nada, and only two of the more than ten samples have definite conodont elements. The only complete and identifiable conodont element (M146N4-1), however, is a long-ranging species (S.A. Leslie, 1994, personal communication), and thus, it is of little biostratigraphic information. From the above integrated discussion of different fossil groups, the Nada Member of the Borden Formation in northeastern Kentucky is biostratigraphically correlative to the Burlington Limestone (Middle Osagean) in the Mississippian type section area, and the crinoid fauna is indicative of correlation to the upper Burlington Limestone.

2.4. Westward Progradation of the Borden Delta Deltaic systems, both ancient and modem, are a major depositional environment with a variety of sedimentary facies and biofacies. The entire structure of ancient deltaic systems is rarely preserved due to erosion. In most cases, only the subaqueous part was preserved. A deltaic system is progradational by nature. It initiates from one location and aggrades as a function of sediment supply, basin tectonics, basin geometry, sea level changes, oceanographic conditions, etc.. The progradation is associated with the shifting of the various facies that occurred in the delta system. The termination of a delta system is due to either large-scale transgression or regression. The general deltaic nature and the westward progradation of the Borden delta was generally accepted based on mainly subsurface and siuface lithostratigraphic data (on the western part, Swann et al, 1965; Lineback, 1969; on the east from West Virginia to eastern Kentucky, Bjerstedt and Kammer, 1988; Matchen and Kammer, 1994). Biostratigraphic

34 support was later provided by Ausich et al. (1979), Lane and DuBar (1983), and Matchen and Kammer (1994). In southern Indiana, the Nada equivalent of the Borden delta platform deposits is the Edwards ville Formation (Rg.2.2). Based on biostratigraphic data from the Edwards ville, it correlates with the upper Osagean Keokuk Limestone of the standard Mississippian section in Iowa. The Keokuk Limestone is the rock unit immediately above the middle Osagean Burlington Limestone in the standard section. Therefore, the Borden delta in northeastern Kentucky is of middle Osagean in age, and in Indiana and Illinois it is of late Osagean age (Fig.23). Thus, the biostratigraphic data from the Nada is consistent with the general interpretation of the the westward progradation of the Borden delta based on physical data.

35 Southern Environmental Northeastern Indiana Interpretation Kentucky

Harrodsburg Post-deltaic Renfro Limestone carbonate Member

Edwards ville Nada Formation Delta Member (Keokuk) platform (Upper Burlington) r Floyds Knob Bed Carwood Fm. Delta slope o Cowbell Locust Point Member I Formation CQ

New Providence f*rodelta Nancy Member Shale I CQ

Farmer’s Turbidites Member

9 Rockford Basin floor Henley Limestone Bed

Figure 2.2 Comparison of Borden delta facies in southern Indiana and northeastern Kentucky (after Lane and DuBar, 1983).

36 Southern Type Section Northeastern Indiana (Iowa) Kentucky

Edwardsville Fra. Spickert Knob Fra. Keokuk Ls. Renfro Member and (late Osagean) Newman Ls.

New Providence Shale Burlington Nada Member Limestone Cowbell Member Rockford Ls. (early and middle Nancy Member Osagean) 9 Hampton Farmers Member Formation Henley Bed (Kinderhookian)

Figure 2.3 Biostratigraphic comparison of Borden delta in southern Indiana and northeastern Kentucky with the standard section in Iowa.

37 CHAPTERS

TAPHONOMY, AUTECOLOGY, AND BIOTIC INTERACTIONS OF THE NADA FAUNA

3.1. Introduction to Taphonomy The term taphonomy was first coined in 1941 by the Russian paleontologist Efremov to embrace the variety of biological, physical, and chemical processes that determine the extent and style of fossil preservation (Allison and Briggs, 1991). Taphonomy is important in the interpretation of the fossil record for two reasons: (1) it helps in understanding the relationship of a fossil assemblage to the original community and, thus, allows to some extent the reconstruction of the community; and (2) recognition of taphonomic processes that have formed the fossil assemblage provides insight into the depositional and postdepositional environments. There are three subsidiary topics of taphonomy: (1) necrolysis: decomposition of the organism upon death; (2) biostratinomy: sedimentational history of the fossils; and (3) fossil diagenesis: chemical and mechanical alteration of the fossils between the time of its burial and collection. Two opposing views exist for accumulation of the fossil record. One is that a fossil assemblage is the result of slow accumulation of shells through a very long period of time, and it is a time-averaged sampling of a sequence of communities over years and from a range of environments. The opposing view is that fossil assemblages are much more likely the result of occasional chance preservation of an individual community. Thus, a fossil

38 assembage may be a fairly reasonable representation of the community existing during a short interval of time. Examples for both views can be found, and the intermediate fossil preservation state is probably the norm. The Nada Member represents a delta platform that was frequently influenced by storms (see Chapter 2). Most fossils were derived from tempestite beds. The Nada Member consists of greenish mudstones and lenticular carbonate interbeds that are wackestones or packstones following Dunham’s terminology. Meyer et ai. (1989) proposed a taphonomic proflle of crinoids and blastoids from the Fort Payne Formation in Kentucky and Tennessee. They also proposed a clade-specific model for the taphonomic resistance of the crinoids. Ausich and Sevastopulo (1994) reaffirmed this model from a taphonomic study of the Hook Head crinoids in Ireland. Because the range of basic constructional factors of the crinoids in the Lower Mississippian is approximately constant (Ausich and Sevastopulo, 1994), this model should also apply to the Nada crinoid fauna. The greenish mudstone, wackestones, and packstones in the Nada are comparable to the green shale, wackestone and packstone facies in the Fort Payne Formation, respectively. This once again confirms the autochthonous nature of the Nada Fauna (Meyer et al., 1989). The taphonomic resistance spectrum of the Hook Head Formation (Ausich and Sevastopulo, 1994) is also observed in the Nada in a similar pattern, i.e. (from most resistant to least resistant) 1) monobathrid camerates—represented by Uperocrinus pyriformis. 2) disparids and cladids— represented by Synbathocrinus wortheni and Cyathocrinities iowensis. 3) diplobathrid camerates—represented by Rhodocrinites barrisi. 4) flexibles—represented by Taxocrinus sp. Another major fossil group in the Nada is the brachiopods. Different groups of brachiopods experienced different taphonomical processes. Most spiriferid shells are disarticulated, i.e., either brachial valve or pedicle valve, represented by Spirifer rowleyi. One exception to this is the athyrid Actinoconchus lamellosits, which is commonly

39 preserved with two valves together. Another unique taphonomic feature of this brachiopod species is that it is almost always preserved as “crushed” thin sheets. This may mean that its hinge system is rather robust (two valves together), but its shell structure is mineralogically more susceptible to crushing dining compaction. Productid brachiopods are commonly found with two valves together although their surface ornamentation is not always present. The hinge system of these brachiopods is probably stronger than that of the spiriferids. The only inarticulate brachiopod in the Nada is Lingula sp. which is typically preserved inside a nodule with well-defined growth lines. Therefore, it is likely that fossilization through the formation of nodules provides better preserved fossils, which may indicate in situ preservation.

3.2. Autecology of the major Nada fossil groups 3.2.1 Autecology of crinoids Crinoids are passive rheophilic suspension feeders (Meyer, 1982). They rely on ambient water currents to carry suspended food particles to the extended tube feet, which are the primary food capturing organs. Breimer (1978) suggested that three types of feeding behavior occurred among crinoids: (1) brachial filtration fan; (2) radial feeding posture and (3) collecting bowl. However, recent studies (Meyer, 1982, 1985; Messing et al., 1988; Baumiller, 1997) bear out that only the first type of feeding behavior is present in most situations. The radial feeding posture is limited to crinoids living inside the crevices on a reef structure where multidimensional currents exist. The collecting bowl posture is only found in deep-sea condition and probably represents a non-feeding posture. Crinoids respond to directional horizontal flow by aligning the arms into a parabolic filtration fan oriented perpendicular to the cuirenL Arms forming the fan are nearly always oriented with the ambulacral groove facing downcurrent (Fig. 3.1).

40 Crinoid niche differentiation was achieved by crinoid tiering and by size selection for food particles within a single tier (Ausich, 1980; Meyer, 1982). Tiering of crinoids made a good use of the length of their columns, to elevate themselves above the substrate (Ausich and Bottjer, 1982; Bother and Ausich, 1986). Food particle size is determined by the width of the ambulacral groo\ e (see more detailed discussion in Chapter 4). Crinoid suspension feeding occurs through aerosol filtration (Rubenstein and Kohl, 1977). There are four types of aerosol filtration, and they are (1) direct interception, (2) inertial impaction, (3) motile-particle deposition, and (4) gravitational deposition. Motile particle capture and gravitational deposition are the most effective means of particle capture at low current velocities, whereas direct interception and inertial impaction are most effective at high current velocities (LaBarbera, 1984). Based on their study of Mississippian crinoids, Kammer and Ausich (1987) concluded that non-pirmulate crinoids may have fed primarily by motile-particle capture and gravitational deposition in low-energy environments, and pinnulate crinoids fed primarily by direct interception and inertial impaction in higher energy currents. Biotic interactions among recent and among fossil crinoids are diverse, and they were reviewed by Meyer and Ausich (1983). Living crinoids had been considered to be relatively fiee from predation until recently (Meyer, 1985). Major predators of crinoids are various types of fishes, crustaceans, sea urchins, and asteroids. Predation commonly occurs as sublethal damage to the visceral mass and arms, firom which the crinoids recover by regeneration (Meyer, 1985). There is little direct evidence of predation on fossil crinoids. However, from a couple of instances that preserved the predation, it can be concluded that fish and some arthropods were predators of ancient crinoids (Meyer and Ausich, 1983). There are many morphological features among the ancient crinoids that are probably antipredation devices (Fig.3.2). They include tegminal clefts, spines and other projections,

41 Direction of Water Current

[

Figure 3.1. Parabolic filtration fan o f the Ordovician camerate crinoidRheocrinus aduncus (after Meyer, 1982).

42 concealment of the crown by coiled, cirriferous column, and others (Meyer and Ausich, 1983). Recent crinoids are reported to have associations with diverse groups of organisms that include polychaetes, molluscs, crustaceans and fishes (Meyer and Ausich, 1983). There are also a number of instances of association of fossil crinoids with other organisms, among which the association of crinoids with platyceratids is one of the most commonly cited and it is treated in detail in Chapter 6 of this dissertation. Two types of associations exist: (1) facultative commensalism, organisms that were epizoans on other substrata in addition to crinoids; (2) obligate commensalism, organisms that are especially adapted to life as crinoid commensals (Fig.3.3). The Nada crinoid faima is dominated by monobathrid camerates. The predominant species is Uperocrinus pyriformis. It is a species with 20 firee arms with pinnules. According to the aerosol filtration theory, and the interpretations of Kammer and Ausich (1987), this crinoid species fed primarily by direct interception and inertial impaction. Another feature of this species is that it has a long anal tube, the height of which is well above the height of the arms. This type of anal tube construction probably indicates that the organism tried to prevent the fecal material from getting into the currents that carry the food particles (sanitation). This species also has a stout, cylindric basal circlet. Another common monobathrid crinoid species is Eretmocrinus corbulis, which also has 20 piimulated arms. A unique feature of this species is that its 20 arms are extremely long and they became wider at the distal end of the arms. The filtration fan that formed from these arms must have been effective considering the smaller size of its calyx. The plates of this species are covered with short spines that could be some type of protective apparatus.

43 Figure 3.2. Possible protective structures of crinoids. a-c. Tegminal clefts for arms; d-g. Developments of spines and other projections;Halysiocrinus h. nodosus (Hall); i.Cenometra bella (Hartlaub); j-k. Concealment stmcturess (after Meyer and Ausich, 1983).

44 Another interesting monobathrid species is Dorycrinus quinquelobus. It has 16 to 20 pairs of arms (total of 40) with lobate arm base. The unique feature of this species is that it possesses five extremely long spines growing out of the radial tegmen plates. These spines were possibly very effective anti-predation devices (Meyer and Ausich, 1983). There is another group of monobathrids in the Nada, namely, the platycrinitids. They have sculptured ornamentations on their plates. One interesting feature of this group of crinoids is that they have helically-shaped stems. When lateral currents flow past this ^pe of stem, part of the current was directed upwards, which possibly increased the amount of current that carried the food particles, thus, increasing the effectiveness of the filtration fan (Riddle, 1989). In addition to camerates, disparid and cladid crinoids are also present in the Nada fauna, although they are not as abundant as the camerates. An ecologically and morphologically unique crinoid group in the Nada is the Calceocrinidae. The calceocrinid species that was found is Halysiocrinus dactylos. Calceocrinids lived with their columns recumbent along the sea floor with strongly bilaterally symmetrical crowns folded back over the column when in a resting posture (Ausich, 1986; Brower, 1987). Instead of elevating themselves from the sea floor with the stem, calceocrinids lived close to the substrate with the stem lying on the sea floor. Therefore, they competed for food resources with many other supension feeders that were close to the sea floor, in particular, the bryozoans and brachiopods. The feeding posture of calceocrinids used to be portrayed as the arms forming a collecting bowl with currents flowing into the oral side of ± e calyx (Moore, 1962). However, according to recent studies of recent crinoids (Meyer, 1982, 1985; Messing et al., 1988), the flow direction of the currents should have been toward the aboral side of the calyx (Ausich, 1986). Calceocrinid arms are nonpinnulate, so, theoretically, gravitational settling and motile-particle deposition should be the primary

45 Figure 3.3. Examples of crinoid epizoans. A. Reconstruction ofCladochonus andEmmonsia attached to a crinoid column; B. Gall ofMyzostoma tenuispinum ; C. Attachment of brachiopod on a crinoid stem;Platyceras D. attached to the crinoid (after Meyer and Ausich, 1983).

46 modes of aerosol suspension-feeding particle capture (Kammer, 1985; Kanuner and Ausich, 1987). Although cladids are not the dominant group of crinoids in the Nada fauna, there are four species from four cladid families. The common features of these crinoids are that their arms are nonpinnulate, and their crown sizes are relatively small. Again, these crinoids do not have a filtration fan with pinnulate arms, and they theoretically used gravitational settling and motile-particle deposition as their major types of food particle capture.

3.2.2. Autecology of Brachiopods Most modem brachiopods are sessile benthic organisms attached mostly to the substrate by a pedicle. All brachiopods are epifaunal except for the linguloids that are infaunal. Ancient brachiopods inhabited much more diverse substratum types than their modem relatives. Many species had a free-living life style on the soft substratum. Some are even thought to have been epiplanktonic, that is, attached to floating seaweed (Rudwick, 1965). Many modem and fossil species are gregarious, being found in large concentrations at one spot and being completely lacking from environmentally similar nearby localities. Similar to crinoids, brachiopods are suspension feeders, filtering plankton and organic detritus from the water with their lophophores. Nonetheless, there is a significant difference between the two, because they are two different types of suspension feeders. Crinoids are passive suspension feeders. They rely exclusively on ambient currents for flow through their infiltration fans. On the other hand, brachiopods are facultative, or weakly active, suspension feeders (LaBarbera, 1984). They create their own currents to move water through the cilia on the lophophore. Another difference is that brachiopods are closer to the substratum. In brach opods, the water current passes laterally into the shell where the food is extracted by the filaments on the lophophore and the water is expelled

47 through the center of the posterior margin (Fig.3.4). One important physiological feature of the articulate brachiopods is that they do not possess a complete digestive system with an anus. Solid waste product must be expelled through the mouth, which is a system that is not efficient when large amounts of sediment are mixed with food (Dodd and Stanton, 1981). Thayer (1986) explained the dominance of the Paleozoic articulate brachiopods by describing several previously undocumented or inadequately described mechanisms for rejecting or excluding non food particles. The lophophores of articulates used different rejection mechanisms according to the concentration of undesirable particles. He compared the feeding mechanism of brachiopods with that of bivalves and refuted the idea that individual filaments made the brachiopod lophophore an inferior pump compared to the fused fiUibranch gill of bivalves. When food resources were very limited on a long term basis, articulate brachiopods should have had an advantage over bivalves. There are several groups of brachiopod fossils found in the Nada. The predominant group is the productids, which developed spines on the shell surface and lost their pedicle in adult form. There are also athyrids, chonetids, spiriferids and inarticulates. The ecology of the productid brachiopods has been extensively studied (Rudwick, 1970, 1978; Muir-Wood and Cooper, 1960; Thayer, 1986). The consensus is that they use their spines and the concave-convex shells to support themselves in a soft, muddy substratum. At an early larval stage, most productids had a conspicuous pedicle as their attachment tool. As the larva grew into the adult stage, its pedicle gradually atrophied and finally disappears. The shell must have become free while still quite small. When passing through the stage of pedicle attachment at an early age, even small fragments of shell, etc., would have been adequate as the sites of initial settlement of the larvae. After this early stage of larval growth, the brachiopods might have been independent of any attachment materials (Rudwick, 1965). The geniculation of their shells also indicates that they

48 probably laid on the substratum with ventral valve at the bottom and with the dorsal valve at the top. Marginatia burlingtonensis has a medium-shell size and a geniculated pedicle valve. Its hinge line is approximately equal to the greatest width of the shell. The pedicle valve is strongly convex with spines all over the surface. The brachial valve is gently concave with reticulate ornamentation. This species lived in a soft, muddy substratum with pedicle valve sinking partially into the substrate. The spines on the pedicle valve helps preventing it from being totally buried into the substrate (Fig3.5). The reticulate ornamentations on the shell surface are probably solidifying structures. Another common productid species is Spinocarinifera sp. It is a small-sized species with the width of the shell approximately 1 cm and the length of the shell about 0.7 cm. Short spines grew over the posterior half of the pedicle valve that is geniculated. This species probably lived a similar manner as Marginatia burlingtonensis. Because the spines are only on the anterior half of the pedicle valve, it is possible that only the anterior half of the shell was submerged into the substratum. Productus sedaliensis is another common Nada productid brachiopod. Compared to Marginatia burlingtonensis, it has a very elongate, convex pedicle valve with sparsely- distributed spines. The brachial valve is approximately flat and lacks spines. The geniculation of the pedicle valve around the posterior part of the shell is very distinctive. It probably had a similar life style as Marginatia burlingtonensis, except that it had a very elongate pedicle valve that spread across the anterior of the shell, so the anterior part of the shell probably held the bulk of weight of the shell. Rhytiophora arcuatus, an overtonid productid, is medium-sized, non-geniculated. Both of its valves have an anterior rim and numerous spines near the hinge, on ears and flanks. It probably lived with the pedicle valve at the bottom with good support of the

49 Exhalant

Inhalant

Exhalant

Exhalant

Figure 3.4. Water current patterns in brachiopods (after Dodd and Stanton, 1981).

50 spines from the ears and flanks. The long spines on the anterior rim may have functioned as some type of sensing devices (Rudwick, 1965). Echinoconchus sp. is a very common brachiopod species in the Nada. Compared to other productids, it has a relatively large body cavi^. Both valves have bands bearing concentric rows of two series of fine prostrate spines. Unlike other productids that do not have spines on their brachial valve, Echinoconchus sp. probably used the spines on the brachial valve as protective devices. It also has a greatly developed umbo in pedicle valve that might be the result of trying to balance the weight-center of the whole shell. Another large group of brachiopod fossils in the Nada is the spiriferids represented by Spirifer rowleyi. Spiriferids have been described as lying on the substratum with their wide interareas on the bottom (Alexander, 1977). As a result, their commissure were vertical, thus elevating the commissure and avoiding the muddy and silty environment close to the substratum (Fig.3.5). Spirifer rowleyi has a rather large sized, well-developed interarea that is vertically grooved, and a very large delthirium. When it was alive, it might have also used its pedicle to attach to the substratum. Both brachial and pedicle valves are convex, indicating a rather large body cavity. Spirifer rowleyi was a very successful brachiopod species that is ubiquitous, present at every section and in different lithologies throughout the studied area. Another brachiopod group in the Nada is the athyrids, represented by Actinoconchus lamellosus. This species has a biconvex shell, relatively large foramen in the pedicle valve, with concentric lamellose flanges over the entire shell. It attached to the substratum with its large pedicle. Almost all of the specimens of this species were vertically crushed between the brachial and pedicle valve, which indicates that this species probably lied on the substrate with either the pedicle valve or the brachial valve at the bottom. Its well-developed lamellose flanges are probably supporting structures that kept the shell from completely sinking into the substratum. One unique taphonomic character of this species is

51 that almost all the specimens were vertically crushed into thin sheets. Compared to productids and spiriferids that are more or less preserved in their original morphology, it can be inferred that the relatively fragile shell of this species could not resist compaction. However, both valves of this species are normally preserved together, indicating that the hinge mechanism of this species is rather tight (Rudwick, 1965). Chonetids in the Nada are represented by Rugosochonetes multicosta. This is a small species with width and length less than 1 cm. It has a row of relatively long spines along the hinge line of the pedicle valve that were used to stabilize the shell on a muddy substratum. The brachial valve is very concave, fitting into the convex pedicle valve and leaving very little space for the internal organs. The living posture of this species is that the pedicle valve at the bottom and brachial valve at the top, thus utilizing the supporting force provided by the hinge line spines. There was a foramen at the pedicle valve indicating that pedicle was used to attach to the substrate when the animal was alive (Rudwick, 1965). The inarticulate brachiopod Lingula sp is also present in the Nada fauna. Interestingly enough, the morphology of this long-ranging brachiopod has stayed almost the same. The majority of modem linguloids live in the intertidal zone. Nevertheless, fossil linguloids were obviously distributed throughout the entire marine shelf environment. Linguloids live an infaunal life with the whole shell dwelling in a burrow. Its long pedicle was attached to the bottom of the burrow. If attacked, it can retract the whole shell deep into the burrow (Rowell, 1965). 3.2.3.Autecology of Trilobites. Trilobite fossils have no modem day representatives. In terms of morphology and perhaps ecology, the nearest living analogue to the trilobites is the xiphosuranUmulus, the horseshoe crab. Limulus lives in shallow water on either mud or sand and feeds on burrowing invertebrates which it obtains by plowing through the sediment (Dodd and

52 M (b)

(c) (d)

Figure 3.5. Morphological adaptations of different brachiopods to soft substrates: (a), thin, flat, concavo-convex shape; (b), spines to increase surface area; (c), large, flat interarea; (d), extended hinge (after Dodd and Stanton, 1981).

53 Stanton, 1981). Trilobites appear to have been largely benthonic, crawling on or in the sediment, and for the most part were probably deposit feeders and scavengers. Paladin chesterensis, one of the most common Mississippian trilobites, is in the Nada Member. It is a very rare Nada fossil, with only two specimens known. This species was interpreted as a benthic deposit feeder by Brezinski (1983). Brezinski (1983) described P. chesterensis as being associated with bivalve-dominated communities that inhabited nearshore shaly environments. P. chesterensis was found in Mississippian rocks throughout the Appalachian basin, the midcontinent, and Utah. Based on the morphology and its facies distribution pattern, Wulff (1991) concluded that this species is a relatively eurytopic trilobite capable of living under various conditions and on various substrates. Another trilobite in the Nada is Australosutura lodiensis. It probably lived a similar life to P. chesterensis. The most conspicuous difference between the two species is that A. lodiensis has series of pustules all over the dorsal skeleton.

3.2.4. Autecology of Cephalopods Cephalopoda are a very important group of fossil invertebrates in the Nada because of its crucial ecological role (predators) although only two species were found in the Nada. The only living species of nautiloid cephalopods is theNautilus pompilius. The chambers ofNautilus and fossil nautiloids were used by the animal to regulate buoyancy. Almost all cephalopods were carnivores preying on a wide variety of invertebrates and fishes. Although Nautilus is a capable swimmer, it depends on food that is associated with sea floor, and this may well have been the case with many fossil cephalopods (Furnish and Gelenister, 1964). Two species of cephalopods existed in the Nada fauna. One is Michelinoceras sp., an orthocerid cephalopod. It has orthoconic longicones with a proportionally small

54 siphuncle. Based on its morphology, it is inferred that this cephalopod species was an active swimmer. Another cephalopod species in the Nada is Subvestinautilus sp., a nautiloid cephalopod. Because of the morphological similarity between this group and the living Nautilus, comparable habitat and mode of life can be presumed. Coiling alone was sufficient to place the center of buoyance near the center of gavity with the hyponome in horizontal position. This group was considered as nektobenthos (Dodd and Stanton, 1981).

3.2.5. Autecology of Rugose Corals There are two groups of corals in the present study. They are rugose corals and tabulate corals. The ecology of tabululate corals is dealt with in a separate section (section 3.3). Rugose corals are relatively abundant in the Nada. No taxonomic attempt was made to species level. Apparently, four major species exist in the Nada. They are Amplexizaphrentis sp., Amplexus sp., Cyathaxonia sp., and Trochophyllum sp. Rugose corals probably lived freely on the substratum. The larval forms were attached to a hard substrata. As they grew older, the animals lived freely on the sediment with the oral side growing upwards. Because rugose corals are extinct and no zooxanthellae are preserved in the fossil record, there is heated argument about whether they are hermatypic or non-hermatypic. Rugose corals often display well-developed daily growth bands, which was considered as evidence of ahermatypic life style. If that is true, then the distribution of rugose corals is controlled by temperature and the water depth (Hill, 1981).

3.2.6. Autecology of Pelecypods

55 One bivalve species, Sanguinolites websterensis is in the Nada Member. It has an elongate shell, clear escutcheon and fine concentric ornamentation. Judging firom its morphology, it probably lived an infaunal life using its siphon to collect food particles from the deposit (Cox, 1969). The only fossil found was an external mold. It is not possible to determine whether the rare occurrence of bivalves is due to low abundance or nonpreservation.

3.2.7. Autecology of Bryozoans Bryozoan fossils are conunon in the Nada Member, although no taxonomic attempt was made to the species level. Most are fenestrates. All bryozoans are colonial with individual zooarium smaller than 0.5 mm.They are facultative active suspension feeders (LaBarbera, 1984). Most bryozoan species require a hard substrate for attachment. They compete with other low-level suspension feeders (such as brachiopods and bivalves) for food resources (Dodd and Stanton, 1981). The low sedimention rate of the Nada provides a good habitat for bryozoans.

3.2.8. Autecology of Gastropods The only gastropod group that is present in the Nada is the platyceratids. Their ecology is dealt with in Chapter 6.

3.3. New type of biotic-interaction between PLATYCERAS (Gastropoda) and CLADOCHONUS (Tabulata) The PaleozoicCladochonus-cdnoxd relations have been well-documented (Rowley, 1901; Hill and Smyth, 1938; Lane, 1973; McIntosh, 1980; Kammer, 1985) and most authors hold that the coral used the crinoid stems as an elevated substratum and did nothing harmful to the crinoid, thus, indicating a symbiotic relation. Although crinoids were

56 apparently the favorite hosts forCladochonus, some are also found on the shell of platyceratid gastropods (Lane, 1973). One peculiarly preserved specimen (OSU 50351) was found at locality 5. This specimen indicates that the Cladochonus colony encrusted a platyceratid gastropod that was still alive and probably still sitting on a crinoid tegmen (Fig.3.6). Previous studies on the Cladochonus-cxmoxd relationship usually divided the growth of the coral colony into two phases, the earlier reptant phase when a reptant ring formed around the crinoid stem and a fiee branch phase when the daughter corallites budded off fi~om the reptant ring of the first phase and branched radially (Hill and Smyth; 1938, Lane, 1973). The diameter of each individual corallite decreases firom the reptant ring to the more distal branches (Kanuner, 1985). In contrast with the Cladochonus-cnnoid interaction mode, the ciment specimen has a Cladochonus beecheri colony growing around the shell of Platyceras (Orthonychia) acutirostre. It starts at the apex of the gastropod shell and grows spirally toward the apertural margin. No reptant ring formed, and there is no obvious size difference between the starting corallites and the later ones. It is very probable that the gastropod was alive while the coral was encrusting it, because if the gastropod shell was dead it should have been at least partly in the sediment, which would prevent the coral from growing to the very margin of the gastropod aperture. The well-developed sinus on its aperture, the deflected growth lines and the irregular apertural margin all indicate that the P. (O., acutirstre was attached to a crinoid tegmen during growth. Thus, it is also very likely that P. (O.) acutirostre was still attached to a crinoid tegmen while the Cladoconus was growing.

57 1 cm

Figure 3.6 Tabulate coralCladochonus beecheri grew spirally around the shell of gastropodPlatyceras acutirostre when the snail was still alive (OSU 50351).

58 Platyceras (Orthonychia) acutirostre is the most abundant plaQ^ceratid species in the study area. Compared with the other specimens of this species that were not encrusted by Cladochonus the current specimen is much smaller in overall size and much thinner and more slender in its shell morphology (Table 3.1). It is possible that the growth of the gastropod was retardated by the encrustation of the coral, and the horizontal growth of the gastropod shell in particular was limited and diminished by the downward spiralling coral corallites. Different from the commensal relations between the crinoid andCladochonus, the coral colony is apparently deleterious to its plaQrceratid host. Why Cladochonus corallites do not form reptant ring around the cone shaped platyceratid shell like those on the crinoid stem is a curious question. This could reasonally be attributable to the synchronous growth of the gastropod shell and the coral colony, whereas in the crinoid case the corallites remain on one columnal of the stem in its first growth phase and thus forming a ring. Lane (1973) reported two platyceratid specimens that were encrusted by Cladochonus beecheri from the Edwardsville Formation at Crawfordsville, Indiana.The corallites were confined to only one side of the gastropod shell in both specimens and, therefore, were interpreted as living on dead gastropod shells that were already incorporated into the sediments. It could be either that the Crawfordsville specimens represent the incomplete preservadon of the current case or thatCladochonus beecheri could encrust on any firm surface that was slightly raised above the sea floor. Additional examples of this association are needed to determine the full range of interactions possible between Cladochonus and Playceras.

59 Specimen Height Diameter of Aperture

MK-63 30 28 MK-6I 19 21 MK-51 26 25 MK-49 22 29 MK-50 23 31 MK-906 21 26 MK-907 29 23 MK-908 31 25

Average 25 26 specimen with tabulate corals (OSU 50351) 21 13

Table 3.1 Comparison of the size (mm) of average specimen with that of the specimen that was attached by Cladochonus beecheri (Grabau).

60 CEÏAPTER4

COMMUNITY PALEOECOLOGY

4.1 .Introduction Community study is a well-established and active discipline in biology and in ecology. Nevertheless, incorporation of ecological concepts and methods into paleoecology has been slow and is a continual process. Numerous definitions of communities exist, ranging from the idea of the community as a superorganism to the view of the community as just a random aggregation of populations in a local habitat (Hoffinan, 1979; Dodd and Stanton, 1981; Bambach and Bennington, 1996). With the advent of the coordinated stasis model, the community concept has been under renewed scrutiny (Brett and Baird, 1995; Brett et al., 1996). In contrast to coordinated stasis, other authors emphasized the random association aspect of communities (Bambach and Bennington, 1996; Bennington and Bambach, 1995; Miller, 1997; Stanton and Dodd, 1997). This study, coupled with previous work on Borden delta communities (Lane, 1973; Ausich et al., 1979; Ausich, 1983) provides an excellent opportunity to study temporal changes in communities and in particular to further test the coordinated stasis model because Borden delta platform communities were successively established as the delta prograded westward. Regardless of the controversy concerning communities, most paleontologists agree that populations of a variety of species lived together in local geographical areas and that these populations interacted with one another in terms of trophic stmcture, niche differentiation, and habitat

61 modification. Three aspects of specific communities are generally emphasized: (I) diversion; (2) trophic structure; and (3) biotic interactions between species. If quantitative data are available for a fauna, then dominance diversi^ and equitability can be calculated. If only absence/presence data are available, then the number of species is used to indicate the diversity of the community. Trophic structiue is a means of understanding the energy flow through a community. Trophic structiue consists of three aspects of a community: (1) the distribution of energy at successive feeding levels; (2) the energy pathways expressed as food webs and chains; and (3) the feeding habits of the organisms (Scott, 1978). The energy flow is usually presented by means of an ecological pyramid with energy measured at several functional levels: producers, herbivores, and carnivores. The trophic structiure of marine communities that has been widely used in paleoecology is the proportion of deposit-feeding and suspension-feeding organisms in the primary and secondary consiuner levels. On the other hand, trophic stmcture in a terrestrial environment consists of all levels of energy flow from plants, herbivores, and high-level carnivores. A complicated food web can usually be constmcted for terrestrial communities. In an attempt to better understand suspension feeders, which dominated many Paleozoic communities, Ausich and Bottjer (1982) proposed the tiering concept Tiering is defined as the vertical subdivision of space by the organisms within a community. The tiering history through the Phanerozoic was considered. The causes of the tiering were interpreted as constmctional and phylogenetic constraints on morphological pathways for evolution, adaptive interactions with the physical environment, and biotic interactions (Bottjer and Ausich, 1983). Tiering was defined by Ausich (1980) as the first order niche differentiation in benthic marine communities, and the second order niche differentiation was the selection

62 for food size. Corals, crinoids, brachiopods, and biyozoans fed on progressively smaller- sized food particles (Ausich, 1980). Biotic interactions in paleocommunity studies are commonly more difficult to establish because evidences for only certain biotic interactions are preserved in the fossil record. Nevertheless, two excellent reviews provide a great deal of information about biotic interactions in the fossil record (Tevesz and McCall, 1983; Boucot, 1990). Assuming that a community can be identified and its attributes determined, how are communities organized and how do they change through time? Numerous suggestions for conununity organization have been proposed, but three will be considered here in detail: guild structure, component concept and coordinated stasis. Bambach (1983) introduced the guild concept, previously used in ecology, to paleoecology. A guild is defined as a group of species that exploit the same class of environmental resources in a similar way. This term groups species that overlap significantly in their niche requirements. Guild analysis, a method of evaluating ecospace utilization within conununities, can be used to compare community structure from different time intervals. A simple community structure with few guilds would have species occupying only a small portion of potential ecospace, whereas a complex corrununity with a large number of guilds would have species scattered more widely in ecospace. Three general factors are used in assigning species to guilds (Bambach, 1983), including food sources, space utilization, and body plan. The components of all three factors are shown in Fig 4.1. For purposes of guild assignments in paleoconununities, class-level taxonomy is commonly used to designate different body plans. The way to establish guilds in paleoconununities includes the following: (1) recognizing the class to which each species belongs; (2) determining the feeding type and food source of each species; and (3) interpreting the life habitat or life position of each species (Bambach, 1983). Examples of guilds in a paleocommunity are given in Table 4.3.

63 I Food Source

Body Plan Food Source Space Utilization - Reproduction - Suspended matter - Pelagic: plankton, nekton - Development -Detritus - Epifauna: mobile, attached - Growth - Plants - Infauna: active, passive, - Physiology - Animals shallow, deep

Figure 4.1 Diagram of three-factor ecospace utilization (after Bambach, 1983).

64 Ausich (1983) proposed the community component concept in his study of Mississippian paleoconununities in southern Indiana. Components are subdivisions of a community that are limited by different environmental factors. Rve community components were identified for the Borden delta platform communities. Because each component was determined by a different set of environmental factors, the distribution of different components would be independent one from the other, thus components rather than communities are natural groupings. The total taxonomic composition of a conununity will depend primarily upon individual component responses to the local physical limiting factors at each site. Therefore, communities as a whole do not react to and interact with the physical environment. In comparison with the guild concept, which also subdivides a community, components emphasize the environmental, rather than the trophic, aspect of communities. Another major topic in conununity study is the temporal changes of communities. There are various models, and the most recent one is “coordinated stasis.” Based on their smdy of the Silurian and Middle Devonian faunas in the Appalachian basin, Brett and Baird (1995) proposed the coordinated stasis model. This model represents an empirical pattern, common in the fossil record, wherein groups of coexisting species lineages display concurrent stability over extended intervals of geological time separated by episodes of relatively abrupt change (Brett et al., 1996). Therefore, the evolution of conununities is similar to the puncmated equilibrium model for species evolution (Eldredge and Gould, 1972). Inspired by Boucot's example of twelve Ecological-Evolutionary units throughout the Phanerozoic, Brett and Baird (1995) proposed ten Ecological-Evolutionary subunits (EE subunits) for the Silurian and Middle Devonian faunas in the Appalachian basin. Each EE subunit lasted approximately 3 to 7 millions of years. The names of the ten EE subunits from old to young are: (1) Medina, (2) Lower Clinton, (3) Upper Clinton, (4) Salina, (5) Keyser, (6) Helderberg, (7) Oriskany, (8) Schoharie, (9) Onondaga, and (10) Hamilton.

65 Overall, the persistence of species with these EE subunits ranges from a low of 66 percent to more than 80 percent In other words, the majoriQr of species did not display any morphological change within EE subunits. For example, in EE subunits 9 and 10, fewer than 10 percent of species appear to have become extinct within the subunit, and more than 80 percent of species are present through the EE subunits. In contrast, relatively few lineages (< 20 percent) persist across boundaries between EE subunits. Spéciation, extinction, and successful immigration rates are all very low within EE subunits, but peak sharply at the boundaries. The time frame of faunal turnover is considered to be approximately less than a few hundred thousand years compared to 3 to 7 millons of years of stasis. As Brett and others are trying to elevate this into a general and universal model, as indicated by the publication of a special issue of Palaeogeography, Palaeoclimatology, Palaeoecology in 1996, other authors (Bambach and Bennington, 1996; Bennington and Bambach, 1996; Miller, 1997; Stanton and Dodd, 1997; Aronson and Pecht, 1997) looked at paleocommunities with a different view. Bambach and Bennington (1996) regarded benthic communities as never truly stable and thought that changes occur at all scales of temporal resolution. They challenged the idea of community evolution and argued that communities are not unifred individuals. Instead, communities are segments of a gradient, not discrete entities. The recent resurgence of interest in community paleocology is probably a harbinger of a new level of synthesis and integration in paleoecological studies. As more paleontologists consider data from a community point of view, new information that is crucial to the definition, structure, and development of paleocommunities will provide better understanding of the interactions between organisms and their environments and better arguments for or against the current models, may even lead to proposals of new models.

6 6 4.2. The Nada Platform Community. The fossils in the Nada Member in the Morehead area made up a commun!^ that was dominated by crinoids and brachiopods and that was present in a relatively quiet, muddy environment The species-level diversity is 56 (Table 4.1). Carnivores, including fishes and cephalopods, were at the top of the ecological pyramid. Secondary consumers included most of the Nada fauna that can be subdivided into suspension feeders, deposit feeders, and coprophagous organisms. Deposit feeders included two species of trilobites and some gastropods. Some platyceratids were coprophagous. Suspension feeders can be subdivided again, following the tiering theory. Crinoids were high-level tierers followed by bryozoans, corals, conulariids, pelecypods, and brachiopods (Table 4.2). The primary producers (algae and plants) and the primary consumers (herbivores) of the Nada community are not preserved (Fig. 4.2).

Fossil groups Number of Species Crinoids 25 Brachiopods 10 Corals 6 Bryozoans 2 Trilobites 2 Cephalopods 2 Gastropods 4 Blastoid 1 Conulariids 2 Pelecypods I Fish I Total 56

Table 4.1 Species Level Diversity of the Nada Community.

67 'Carnivore > level (fish and cephalopods)

Secondary consumer level (crinoids, brachiopods, bryozoans, corals)

Primary consumer level (not preserved in the Nada)

Primary producer level (not preserved in the Nada)

Figure 4.2 Ecological pyramid o f the Nada Community including four levels o f organisms.

6 8 Trophic Position Taxonomic Composition Low-level Suspension 32.1% (17 species) Feeders High-level Suspension 50.9% (27 species) Feeders

Other Trophic Groups 17.0% (9 species)

Table 4.2. Taxonomic and Trophic Relations of the Nada Communier.

As high-level suspension feeders, crinoids were the dominant trophic group in the Nada community. The dominant species is Uperocrinus pyriformis. The crinoid fauna consists of mainly monobathrid camerates (14 of 25 the total crinoid species). Five crinoid clades existed during the Lower Mississippian, and they are camerates (biserially pinnulate), advanced cladids (uniserially pinnulate), primitive cladids (nonpinnulate), disparids (nonpinnulate), and flexibles (nonpinnulate) (Ausich, 1980; Kammer et al., 1998). AU these clades have representatives in the Nada. The presence or absence of pinnules, density of arm branches, and width of the ambulacral groove are directly related to their feeding habits (Ausich, 1980; Kammer and Ausich, 1987). Pinnulate crinoids were environmental specialists, and they tend to live in high-energy environments that limit their distribution. In contrast, non-piimulate crinoids were environmental generalists, and they can exist in both low- and high-energy environments. The pinnulate/non-pinnulate dichotomy is thought to have played a major role in determining crinoid niches, especially with regard to current velocity. Based on the above discussion on the feeding habits of crinoids, rive guilds are established in the Nada, and they correspond to the rive crinoid clades. In the Nada community, camerates include rhodocrinitids, batocrinids, coelocrinids, actinocrinids, platycrinitids; advanced cladids include graphiocrinids and scytalocrinids; primitive cladids 69 include cyathocrinitids, mastigocrinids and barycrinids; disparids include synbathocrinids and calceocrinids; flexibles include taxocrinids. Among the five clades, the advanced cladids are unique in their feeding habits. They are the only Paleozoic crinoid group that possessed muscular articulation between brachials and pinnules (Ausich and BaumiUer, 1993), which provided the capability of rapid, directed movement of the arms, pinnules, and crown. Inferred fi'om their observation of modem crinoids, Kammer et al. (1998) considered advanced cladids to have had a pinnule-flicking function, which could explain why they were mostly found in high turbulance siliciclastic settings where the filtration fan could be clogged frequently. The brachiopods fiom the Nada fauna are grouped into five guilds. The inarticulate Lingula sp. is one guild by itself because of its unique morphology and life habitat. Actinochonchus lamellosus is one guild as a result of its shell structure, life position, and use of pedicle. Two spiriferid species, Spirifer rowleyi and Spirifer latior, are grouped into one guild because of their similar life style, similar shell morphology, and similar life position. Five productid species {Marginatia burlingtonensis, Spinocarinifera sp., Rhytiophora arcuatus, Echinoconchus sp., and Productus sedaliensis) are grouped into one guild because they all have spines on the pedicle valve, they all have lost their pedicle in their adult life, and they all have concave (flat)-convex shell morphology. The chonetid Rugosochonetes multicosta is a separate guild because of its small size, its unique spine orientation (one row of spines on the hinge) and its life position. Corals in the Nada fauna are grouped into two guilds, one for rugose corals, and the other for tabulate corals. The tabulate corals in the Nada are encrusters, which are very different firom the free living life of rugose corals.There are two species of trilobites in the Nada, and both are grouped into one guild (see Chapter 3). Two species of cephalopods exist in the Nada. One is an orthocerid, and the other is a nautiloid. Because of their sharp difference in shell morphology, they are categorized into two separate guilds. There are

70 Trilûbita Asymmetry of cephalon to pygidium Symmetry between cephalon and pygidium Elaborately spinose Blind, short diorax, often with pitted fringe on cephalon Agnostid form Articulate Brachiopoda Small (under I cm), strongly biconvex Large, strongly biconvex, pedunculate Large, stron^y biconvex, alate pedunculate Slightly biconvex or plano-convex, pedunculate Relatively flat, free-lying Inflated, free-lying Spinose Cemented Gastropoda Cap-shaped grazers Spired g ^ e r s Epifaunal predators Tiny, interstitial Infaunal suspension-feeders High-spired infaunal predator Low-predators

Bivalvia Nonsiphonate shallow infaunal suspension-feeder Siphonate shallow infaunal suspension feeder Sluggish siphonate deep infaunal suspension feeder Rapid siphonate deep infaunal suspensions feeder Deep infaunal mucus-tube suspension feeder Nonsiphonate deposit feeder Siphonate palp-probiscide deposit feeder Endobyssate (semi-infaunal) suspension feeder Erect epibyssate suspension feeder Reclining epibyssate suspension feeder Free-lying epifaunal suspension feeder Swimming epifaunal suspension feeder Cemented epifaunal suspension feeder

Table 4.3. Examples of guilds in paleocommunities (after Bambach, 1983).

71 four species of piatyceradd gastropods, and they are grouped into two guilds. One is coprophagous, and the other is deposit feeding (see Chapter 6). Because only fenestrate bryozoans were present, all the bryozoans are grouped into one guild. There are two species of conulariids, and both of them are very similar in terms of morphology. Conulariids were designated into a separate phylum (Babcock and Feldmann, 1986) because of their unique body plan. Therefore, the two conulariid species are grouped into one guild. There is one pelecypod species, one blastoid species, and one piece of fish bone. All of them, obviously, represent separate guilds (Table 4.4). Brachiopods and crinoids have the largest guild number. This means, according to the definition of the guild, that brachiopods and crinoids have more adaptive strategies than the remainder of the fauna in the Nada conununity. There are 56 species and 22 guilds in the Nada community. The average number of guilds from the Carboniferous communities studied by Bambach (1983) was 13 and the median number of species was 22.The larger species richness (56 to 22) is correlated to the larger number of guilds (22 to 13), indicating that more ecospace occupation instead of guild packing is the rule in the Nada community.

Groups Number of Guilds crinoids 5 brachiopods 5 corals 2 trilobites 1 cephalopods 2 platyceratids 2 bryozoans 1 conulariids 1 pelecypods 1 blastoid 1 fish 1 Total 22

Table 4.4 Distribution of Guilds in the Nada Community. 72 In addition to the guild concept that emphasizes body plan and trophic relations of the community, the community component concept (Ausich, 1983) focuses on the physical environmental factors that control the distribution and development of communities. Five community components were proposed for Early Mississippian communities: (1) those organisms that were sensitive to conditions at the sediment-water interface; (H) organisms controlled primarily by prevalent energy conditions and the dominant size of suspended food particles; (HI) organisms that were controlled by turbidity; (TV) organisms with a dependent relationship with others either commensal, parasitic, or predater-prey; (V) organisms that were controlled by depositional rates. The different fossil groups that belong to different community components are shown in Table 4.5. Most of the Nada conununity members belong to Component1 and HI (20 species for 1 and 26 form), indicating that conditions at the sediment-water interface and the energy conditions above the bottom supported life for the Nada Community (Table 4.6).

Components Taxa 1. Limited by conditions at the calcareous algae (?), foraminifera, sediment-water interface cnidiarians, bryozoans, brachiopods, especially grain size, grain gastropods, ostracods, trilobites, sorting, substratum holothurians, echinoids, stelleroids, other mobility low level suspension feeders, deposit feeders, scavengers, and grazers n. Limited by turbidity sponges, suspension-feeding bivalves HI. Limited by energy crinoids, blastoids conditions of environment IV. Dependent organisms limited platyceratids, Phosphannulus, certain by biotic interaction shell borings, other parasites, relationships conunensals, and predators V. Controlled significantly chordates by depositional rate

Table 4.5. Early Mississippian community components (after Ausich, 1983).

73 These two components cover the bulk of the taxonomic vaiiabiliQr in the Nada community as defined by the component concept (Ausich, 1983).

Community Components Number of Species Percentage 1 21 39.6% n 1 1.9% m 26 49.1% IV 2 3.8% V 3 5.7%

Table 4.6. Nada Community Components.

4.3. Comparison of community developments of the Nada Member with that of the Edwards ville Formation The hypothesis of coordinated stasis holds that long term community developments are composed of periods of taxonomic stasis that are 3 to 7 million years long and are punctuated by abrupt (less than a Hundred thousand years) taxonomic change. The middle Osagean Nada Member and late Osagean Edwardsville Formation are the platform of the Borden delta at different times, with the time difference between them approximately 3.5 millions of years (Harland, 1990; Young and Laurie, 1996). Therefore, a comparison of the paleocommunities developed in the two units will provide a good test case of the coordinated stasis model. The Borden delta reached eastern Kentucky during middle Osagean time as represented by the Nada (see Chapter 2). When it prograded into southern Indiana, it was late Osagean as represented by the Edwardsville Formation (Ausich et al., 1979). 74 Three communities in the Edwardsville Formation delta platform were established, and they were related to three depositional facies, distributary sandstone or siltstone channels (Waldrip Site or Crawfordsville), skeletal carbonate banks (Allens Creek), and interdis tributary mudstone (Boy Scout Camp) (Ausich, 1983). The Waldrip Site community was dominated by fenestrate bryozoans and poteriocrine crinoids. This community has the lowest diversity of Monroe Reservoir skeletal communities. The Allens Creek conununity was dominated by monobathrid camerate and disparid crinoids. Different spots across the bank had variable taxonomic compositions, and it was interpreted to represent the original patchiness of the bank community. The Boy Scout Camp, the interdistributary mudstone community, had the most diverse epifaunal suspension-feeding community at Monroe Reservoir (125 species). It was dominated by fenestrate bryozoans, cystoporate bryozoans, cyathocrine cladid crinoids, monobathrid camerate crinoids, and spiriferid brachiopods. Crinoid data from the Boy Scout Camp community indicates that the most abundant species are the cyathocrines Cyathocrinites parvibrachiatus, Barycrinus hoveyi and Barycrinus asteriscus; the disparid Halysiocrinus tunicatus; the diplobathrid Gilbertsocrinus tuberosus; and the monobathrid Platycrinites sc^ordi and Actinocrinites gibsoni (Ausich, 1983). The Nada Member of the Borden Formation in northeastern Kentucky was predominantly a mudstone facies with rare carbonate lenses. Thus, in terms of the depositional enviromnents, the Nada community is comparable to the interdistributary mudstone community (Boy Scout Camp, which will be called the Edwardsville mudstone community hereafter). The two communities developed within the same basic paleoenvironment (mudstone facies on a delta platform), but the Nada community was approximately 3.5 millions years older than the Edwardsville mudstone community. The taxonomic compositions of the Nada community and the Edwardsville mudstone community are summarized in Table 4.7. There are similarities as well as striking

75 differences in terms of the taxonomic composition of the two communities. First, the total diversity of the Nada communiQf is much smaller than the Edwardsville mudstone community (56 to 125). Another major difference is that bryozoans are one of the dominant groups in the Edwardsville community (26.4%), whereas they are negligible in the Nada community (3.8%). No conulariids, cephalopods and blastoids were present in the Edwardsville mudstone community. On the other hand, foraminiferans, poriferans, annelids, ostracods, stelleroids, echinoids, and holothuroids were not found in the Nada community. It is difBcult to determine if this is a result of taphonomic or preservational bias or a true representation of differences in the original community. Nevertheless, because all these groups are not dominant in both conununities, they may not carry much weight in the paleoecological analyses. Crinoid species and brachiopod species were both dominant groups in the two communities, but bryozoan species were dominant in the Edwardsville mudstone community and rare in the Nada community. Crinoids in the two conununities are important contributors to the community diversity. A genus- and family-level comparison of the crinoid faunas is presented in Table 4.8. The Nada community is dominated by batocrinids, such as Uperocrinus and Eretmocrinus, whereas the Edwaidsville mudstone community is dominated by cyathocrine cladids such as Cyathocrinites and Barycrinus. Dichocrinids, catillocrinids, synerocrinids and nipterocrinids were in the Edwardsville mudstone community, whereas mastigocrinids only existed in the Nada community. The Edwardsville mudstone conununity has more diverse flexibles with three families (taxocrinids, synerocrinids and nipterocrinids), whereas the Nada has only one family (taxocrinids). The trophic groupings of the Nada and the Edwardsville mudstone communities are summarized in Table 4.9. The dominant trophic groups in the Nada community are the high-level suspension feeders, whereas in the Edwardsville mudstone conununity, low-

76 level suspension feeders are dominant The non-suspension feeders are negligible in the Edwardsville mudstone community (2%), whereas in the Nada community, the non- suspension feeders make a large part of the whole community (17%).

Taxonomic Number of Species (Percentage) Groups Nada Communia Edwardsville Community Monobathrid camerate 15 (28.3%) 17 (13.6%) crinoids Diplobathrid camerate 2 (3.8%) 1 (0.8%) crinoids Disparid crinoids 2 (3.8%) 3 (2.4%) Cladid crinoids 5 (9.4%) 14 (11.2%) Flexible crinoids 1 (1.9%) 4 (3.2%) Brachiopods 10 (18.9%) 19 (15.2%) Cnidarians 6 (5.7%) 7 (5.6%) Bryozoans 2 (3.8%) 33 (26.4%) Trilobites 2 (3.8%) 1 (0.8%) Cephalopods 2 (3.8%) 0 Gastropods 4 (7.5%) 3 (2.4%) Blastoids 1 (1.9%) 0 Conulariids 2 (3.8%) 0 Pelecypods I (1.9%) 2 (1.6%) Chordates (fish) 1 (1.9%) 1 (0.8%) Foraminiferas 0 5 (4.0%) Poriferas 0 1 (0.8%) Annelids 0 1 (0.8%) Ostracods 0 9 (7.2%) Stelleroids 0 1 (0.8%) Echmoids 0 2 (1.6%) Holothuroids 0 1 (0.8%) Total 56 125

Table 4.7. Taxonomic comparison between the Nada community and the Edwardsville community.

77 Nada Edwardsville Taxonomy community community Camerates Family Rhodocrinitidae Roemer 1855 Rhodocrinites^AjXLex \%2\ x Gi7£>emocrfnojPhillips 1836 x x Family Batocrinidae Wachsmuth and Springer 1881 Uperocrinus Meek and Worthen 1865 x Macrocrinus Wachsmuth and Springer 1855 x x Eretmocrinus Lyon and Casseday 1859 x x Family Dichocrinidae Miller 1889 Dichocrinus Munster 1839 - x Paradichocrinus Springer 1926 - x Family Coelocrinidae Bather 1899 Aorocrinus Wachsmuth and Springer 1897 x Dorycrinus Roemer 1854 x x Agaricocrinus Hall 1858 x x Family Actinocrinitidae Austin and Austin 1842 Actinocrinites Miller 1821 - x Blairocrinus'MS\e,r\%9\ x Discocrinus new genus x Family Pla^ycrinitidae Austin and Austin 1842 Platycrinites Miller 1821 x x

Disparids Family Synbathocrinidae Miller 1889 Phillips 1836 x x Family Calceocrinidae Meek and Worthen 1865 Halysiocrinus Ulrich 1886 x x Family Catillocrinidae Wachsmuth and Springer 1886 Catillocrinus Shumard 1865 - x Cladids Family Cyathocrinitidae Bassler 1938 Cyathocrinites Miller 1821 x x Family Barycrinidae Jaekel 1918 Barycrinus Wachsmuth and Worthen 1868 x x Family Mastigocrinidae Jaekel 1918 Atelestocrinus Wachsmuth and Springer 1886 x Family Poteriocrinitidae Austin and Austin 1842 Springericrinus Jaekel 19\S - x Family Graphiocrinidae Wachsmuth and Springer 1886 Holcocrinus Kirk 1945 x x Family Scytalocrinidae Moore and Laudon 1943 Hisrocrinus Kirk 1940 x x Table 4.8 Genus and family level comparison of the crinoid fauna from Nada and Edwardsville mustone communities (continued next page).

78 (Table 4.8 continued from previous page)

Nada Edwardsville Taxonomy community community (Table 4.8 continued from the previous page) Flexibles Family Taxocrinidae Angelin 1878 Taxocrinus Phillips 1843 X X Parichthyocrinus Springer 1902 - X Family Synerocrinidae Jaekel 1918 Onychocrinus Lyon and Casseday 1860 - X Family Nipterocrinidae Jaekel 1918 Nipterocrinus Wachsmuth 1868 X

Table 4.8 Genus and family level comparison of the crinoid fauna from Nada and Edwardsville mustone communities.

The community components of the two conununities are summarized in Table 4.10. In both communities. Component I and HI are dominant, indicating that the physical environments of the two communities are largely similar, which is consistent with the facies analysis and general delta platform environment. Nevertheless, component I contains many more species in the Edwardsville mudstone commtmi^ than in the Nada community (64.8% to 39.6%).

79 Trophic Position Taxonomic Percentage Nada Community Edwardsville Community Low level suspension 32.1% 64% feeders High level suspension 50.9% 34% feeders Other trophic groups 17.0% 2%

Table 4.9. Trophic groupings in the Nada and Edwardsville mudstone communities.

Components Number of Species (Percentage) Nada community Edwardsville community I 21 (39.6%) 79 (64.8%) n 1 (1.9%) 3 (2.5%) m 26 (49.1%) 39 (32.0%) IV 2 (3.8%) 3 (2.5%) V 3 (5.7%) 1 (0.8%)

Table 4.10. Community Components in the Nada and Edwardsville communities.

80 PERCENTAGE

00

EdwanitvlH*

Low Level Sutpontlon Feeders High Level Suspension Feeders Other Groups

Figure 4.3. Histograms of the trophic groupings in the Nada and Edwardsville mudstone communities PERCENTAGE

?3

EdwartftvUta

Nada

Figure 4.4. Distributions of community components in the Nada and Edwardsville mudstone communities Taxonomic Groups Number of Guilds Nada Community Edwardsville Community Crinoids 5 5 Brachiopods 5 8 Coelenterates 2 1 Trilobites 1 1 Cephalopods 2 0 Gastropods 2 2 Bryozoans 1 5 Conulariids 1 0 Pelecypods 1 1 Blastoids 1 0 Foraminiferans 0 1 Poriferas 0 1 Annelids 0 1 Ostracods 0 1 Stelleroids 0 1 Echinoids 0 1 Holothuroids 0 1 Chordates 1 1 Total 22 31

Table 4.11. Guilds in Nada and Edwardsville mudstone communities.

The number of guilds in the Edwardsville mudstone community was much larger than that of the Nada community (Table 4.11). The increased diversity in the Edwardsville mudstone community (see Table 4.7) is compatible with the increased number of guilds. Therefore, the Edwardsville mudstone community utilized more ecospace than the Nada community. Those species that are present in the Edwardsville mudstone community but absent in the Nada community are new ecospace exploiters.

4.4. Coordinated stasis or coincident relative stability, which one fits the picture better? The temporal change, or evolution, of communities has various connotations. In community paleoecology studies, the long-term “evolution” of conununities (10 to a 83 hundred Ka) should be carefully distinguished from short-term community succession (10 to a few hundreds years) (Brett, 1998). The Ecologie Evolutionary Subunits (EE subunits) of Brett and Baird (1995) lasted approximately 3 to 7 millions years. In the present study, the time between the Nada community and Edwardsville mudstone community is approximately 2.5 to 3.5 millions years (Harland, 1990; Young and Laurie, 1996), which is within the time span for EE subunits.

Because both the Nada community and the Edwardsville mudstone communier were developed in almost the same paleoenvironment (mudstone facies on the same delta platform), which is consistent with the stable paleoenvironment within an EE subunit, we would expect each to have comparable faunas, and at least 60 percent of the species should be shared by the two communities if we apply the coordinated stasis model (Brett et al., 1996). Does coordinated stasis explain the data from these two communities? The species level diversity of the Nada is 56 species. The species level diversity for Edwardville mudstone community is 125. On the species level, there are only three species that existed in both communities, and they are Cladochonus beecheri, Actinoconchus lamellosus, and Platyceras equilateralis. These co-occurring species are only 9.7 percent of the Nada and 2.2 percent of the Edwardsville mudstone community. At the genus level, the diversity of Nada is 46 genera, and the diversity of Edwardsville mudstone community is 105 genera. However, there are only 17 genera that existed in both communities, and they are Actinoconchus, Cladochonus, Spirifer, Platyceras, Halysiocrinus, Synbathocrinus, Cyathocrinites, Barycrinus, Histocrinus, Holcocrinus, Taxocrinus, Gilbertsocrinus, Agaricocrinus, Dorycrinus, Eretomocrinus, Macrocrinus, and Platycrinites. These co­ occurring genera are 37 percent of the Nada and 16.2 percent of the Edwardsville mudstone community. Even at the genus level, many fewer than 60% of taxa are shared by the two communities. If we consider the trophic groupings, the two communities are also very different. The Edwardsville mudstone community is dominated by low-level suspension

84 feeders, whereas the Nada communia is dominated by high-level suspension feeders. If viewed from the point view of communia components, however, both communities display similarly, and both communities are dominated by Components I and QI. Because community components are subdivisions of a community that are limited by different environmental factors, we can presumably deduce that the developments of the two communities were largely controlled by the physical environmental factors.

Variability Source TAXONOMIC Temporal Genetic evolution Biogeographic provincialism Migration barriers Introprovincial differences Migration potential of taxa Environmental Adaptations to major environmental parameters Components Adaptation to combinations of local environmental parameters Intracomponents Vagaries of larval recruitment MORPHOLOGIC Morphologic variability Intraspecific genetic or environ­ mentally induced variability

Table 4.12. Sources and causes for variability among communities (after Ausich, 1983).

During one EE subunit of Brett and Baird (1995), community members are nearly constant, show very similar taxonomic composition, species richness, dominance-diversity patterns, and guild structure. From the above analysis the Nada community and the Edwards ville mudstone community differ in species richness, taxonomic compostion, and guild structure. The abrupt change between the EE subunits were thought to involve large scale environmental perturbation (Brett et al., 1996). In the current case, both Nada and Edwards ville mudstone communities were developed in the same delta platform, and no distinct environmental factors separate them. Yet we failed to discern the stasis. Differences between the Nada and the Edwards ville mustone communities can be explained either as a change across and EE subunit boundary at the middle to late Osagean, consistent with 85 coordinated stasis, or as communier change that would be against coordinated stasis. In defining the concept of coordinated stasis, Brett et al. (1996) stated that the majotiQr of EE subunit boundaries recognized in the middle Paleozoic of the Appalachian Basin region are also recognizable in western Europe, Bohemia, Morocco, and Gondwana continents. The possible boundary events are widespread anoxia, major climatic changes, and/or large scale sea level changes (possibly eustatic). In the current study, as stated earlier, the Nada and Edwardsville represented very similar paleoenvironments. There is no evidence for large scale environmental perturbations between the two. Therefore, it seems unlikely that an EE subunit boundary was crossed in the 3.5 million years between the Nada and Edwardsville communities, and we need to look at other models unless large scale boundary events can be established in future studies.

Brett et al. (1996) tentatively invoked the role of ecological locking as the cause that maintains the paleoecological stability (stasis). However, coevolutionary species were extremely rare both in the current study and in the Silurian and Devonian faunas in the Appalachian basin. Therefore, seeking a universal explanation that involves ecological locking probably does not lead to any new understanding of the stasis of the Appalachian fauna and the non-static communities observed in this study and in others (Bambach and Bennington, 1996; Aronson and Pecht, 1997). Morris et al. (1995) cited hierachical ecology as a possible cause of paleoecological stasis. However, hierachical ecology deals with community changes in the scale of community succesion that is much shorter than the EE subunits. Upscaling community succession into the geological time scale does not have much support from the actual data (Brett, 1998). Miller (1997) proposed the term “coincident relative stability” as a contrast to coordinated stasis. From an episodic view of the natural systems, global and local environmental perturbations controlled the developments of paleocommunities. No ecological interaction or “ecological locking” were meant in the concept of coincident

8 6 relative stability. Obviously^ the data from the Nada community and the Edwardsville mudstone communier support coincident relative stability more than coordinated stasis because large scale ecological locking, except for the well-known platyceratid-crinoid relation, and community stasis, were not present.

87 CHAPTERS

SYSTEMATIC DESCRIPTION OF THE CRINOED FAUNA

5.1. Introduction

The Lower Mississippian Borden Delta was recorded by the Borden Formation in eastern Kentucky (Chaplin, 1980; Sable and Dever, 1990). It consists of, in ascending order, the Henley Bed, Farmers Member, Nancy Member, Cowbell Member and Nada Member. Crinoids are well known from the Borden farther west, including the famous Crawfords ville and Indian Creek crinoid beds from central Indiana (Van Sant and Lane, 1964; Lane, 1973; Ausich and Lane, 1980; Kammer, 1984). However, only a single low diversity fauna has ever been described from the Borden Formation of eastern Kentucky (Lane and DuBar, 1983). The crinoid fauna described here is from the Nada Member that is interpreted as delta platform deposits. A total of eight localities have been systematically collected for crinoid specimens.The crinoid fauna described by Lane and Dubar (1983) is one of these eight localities (see Appendix D). The Nada Member crinoid fauna is now especially interesting because it displays a much greater diversity, more than 25 species, with one new genus and four new species. The correlation of this unit to the Mississippian standard section can be further verified. 5.2. Locality and Stratigraphy

88 The study area is located in the vicinity of MoreheacL Kentucky. Most of the studied sections are in Rowan, Bath and Meniffee Counties. This area lies along the western border of the Appalachian Basin and approximately 138 km east of the axis of the Cincinnati Arch. The Nada Member is the upper most part of the Borden Formation in eastern Kentucky. Lithologically, it is a unit of gray, greenish shales intercalated with silty mudstone and siltstones. Crinoid faunas occur in facies interpreted to be the distal part of the Borden delta platform. As such, the terrestrial influence on the Nada deposits is negligable. Both Lane and DuBar (1983) and the current study show that the Nada fauna is closely allied to that of the Burlington Limestone in the Mississippian stratotype area, thus, indicating a Middle Osagean age.

Community paleoecology studies have been completed for the facies of the Borden delta in northern Kentucky and southern Indiana (Ausich et al., 1979; Ausich, 1983; Kammer, 1983). The depositional equivalent of the Nada Member in southern Indiana is the Edwardsville Formation, which is late Osagean (Ausich et al., 1994). As a result of the westward progradation of the Borden delta, the Edwardsville Formation should be younger than the Nada Member (Ausich et al., 1979; Lane and DuBar, 1983), but both represent delta platform deposits. This provides us with an opportunity to examine two environmentally similar and temporally different faunas and to compare the similarities and differences in faunal composition. 5.3. Faunal Analysis The Nada fauna is now understood to consist of 25 species within 18 genera and 12 families (see Table 5.1). The majority are advanced camerates (18 species), but disparids, cladids and flexibles are also present. Most crinoid specimens are from the carbonate stringers in grey, greenish shale, which is the dominant lithology of the Nada Member. The whole fauna represents a typical normal, shallow marine environment Paleozoic fauna,

89 with the presence of crinoids, brachiopods, corals and bryozoans. Among the 25 described species, twelve were originally described from the Upper Burlington Limestone of the Mississippian stratoQrpe sections in Iowa and Missouri. Lane and DuBar(1983) claimed an Upper Burlington age for the Nada fauna. This study agrees with their age determination. One new genus (Discocrinus), and four new species {Discocrinus protubérants, Uperocrinus acuminatus, Aorocrinus nodulus, and Atelestocrinus kentuckyensis) are described from this fauna.

90 Reported Occurrences Camerates Family Rhodocrinitidae Roemer, 1855 Rhodocrinites barrisi (Hall, 1861) Upper Burlington Limestone Gilbertsocrinus tuberculosis (Hall, 1860) Upper Burlington Limestone Family Batocrinidae Wachsmuth and Springer, 1881 Uperocrinus pyriformis (Shumard, 1855) Upper Burlington Limestone Uperocrinus acuminatus new species Nada Member of Borden Fm Macrocrinus koninki (Shumard, 1855) Upper Burlington Limestone Eretmocrinus corbulis (Hall, 1861) Lower Burlington Limestone Eretmocrinus calyculoides (Hall, 1860) Upper Burlington Limestone Family Coelocrinidae Bather, 1899 Aorocrinus nodulus new species Nada Member of Borden Fm Dorycrinus quinquelobus Oia]l, 1860) Upper Burlington Limestone Agaricorinus stellatus (Hall, 1860) Upper Burlington Limestone Agaricocrinus bullatus Hall, 1858 Upper Burlington Limestone Family Actinocrinitidae Austin and Austin, 1842 Discocrinus protuberatus new genus, new species Nada Member of Borden Fra Blairocrinus sp. Family Platycrinitidae Austin and Austin, 1842 Platycrinites glyptus (Hall, 1861) Upper Burlington Limestone Platycrinites planus (Owen and Shumard, 1850) Upper Biulington Limestone Platycrinities tennuibrachiatus Upper Burlington Limestone Meek and Worthen, 1869 Platycrinities ?incomptus (White, 1893) Upper Burlington Limestone Disparids Family Synbathocrinidae Miller, 1899 Synbathocrinus wortheni Hall, 1858 Upper Burlington Limestone Family Calceocrinidae Meek and Worthen, 1865 Halysiocrinus dactylus (Hall, 1860) Upper Burlington Limestone

Table 5.1. Nada Member crinoid taxa and occurrences (continued next page).

91 (Table 5.1 continued from previous page) Cladids Family Cyathocrinitidae Bassler, 1938 Cyathocrinites iowensis Burlington Limestone to (Owen and Shumard, 1850) Warsaw Limestone Family Mastigocrinidae Jaekal, 1918 Atelestocrinus kentuckyensis new species Nada Member of Borden Fm. Family Graphiocrinidae Wachsmuth and Springer, 1886 Holcocrinus spinobrachiatus (Hall, 1861) Lower Burlington Limestone and Ste. Genevieve Limestone Family Scytaiocrinidae Moore and Laudon, 1943 Histocrinus sp. Family Barycrinidae Jaekel, 1918 Barycrinus sp. Hexibles Family Taxocrinidae Angelin, 1878 Taxocrinus sp.

Table 5.1. Nada Member crinoid taxa and occurrences.

92 5.4. SYSTEMATIC PALEONTOLOGY Terminology follows Ubaghs (1978). Supergeneric taxonomy follows Ausich (1998). All specimens are housed in the Orton Geological Museum of The Ohio State University (OSU) and the U.S. National Museum of Natural History (USNM). See Appendix O for a description of crinoid localities. Phylum Echinodermata Class Crinoidea Miller, 1821 Subclass Camerata Wachsmuth and Springer, 1885 Order Diplobathrida Moore and Laudon, 1943 Suborder Eudiplobathrida Ubaghs, 1953 Superfamily Rhodocrinitacea Roemer, 1855 Family Rhodocrinitidae Roemer, 1855 Genus Rhodocrinites Miller, 1821 Type species.—Rhodocrinites versus Miller, 1821; by subsequent designation (Roemer, 1855). Rhodocrinities barrisi (Hall, 1861) Figure 5.2.1, 5.2.2 Rhodocrinus barrisi Hall, 1861a, p. 322; 1861b, p. 9; 1872, PI. 6, figs. 16, 17; Bassler and Moodey, 1943, p. 662. Rhodocrinites barrisi (Hall, 1861a). Bassler and Moodey, 1943, p. 662. Discussion.- The current specimens with characteristic star-shaped calyx plate sculpturing and nodose tegmen plates fits all the previous descriptions and illustrations of R. barrisi. The middle portions of the plates have spine-like processes or elongate nodes, connected by usually five-fold radiating and well-marked ridges, which traverse the sutures and connect with the radiating ridges of the adjoining plates. The nodes on the basais are

93 directed obliquely downward, whereas those on the radiais and interradiais point horizontally. This species was previously known only from the upper Burlington Limestone of Burlington and Pleasant Grove, Iowa. Materials examined.— Two specimens with well-preserved sculpturing and arm facets are OSU 50352, OSU 50353. Occurrence.— Upper Burlington Limestone, Burlington and Pleasant Grove, Iowa; Nada Member of the Borden Formation, Morehead, Kentucky at localities 2 and 7.

Genus Gilbertsocrinus Phillips, 1836 Type species.- Gilbertsocrinus calcaratus Phillips, 1836; by subsequent designation (Bassler, 1938). Gilbertsocrinus tuberculosus (Hall, 1860) Trematocrinus tuberculosus Hall, 1860, p. 75. Gilbertsocrinus tuberculosus (Hall, 1860). Wachsmuth and Springer, 1897,p. 243, PI. 17, figs, 5a-3e; Bather in Lankester, 1900, p. 201, Fig. 127.2; Bassler and Moodey, 1943, p. 488; Haugh, 1973, p. 86, PI. 2, fig. 7; Webster, 1977, p. 89; Ubaghs in Moore and Teichert, 1978, p. T197, Fig. 166.3; Lane and DuBar, 1983, p. 115, fig. 3K; Webster, 1986, p. 154; Webster, 1988, p. 89. Discussion.— One specimen was described and assigned to this species by Lane and DuBar (1983). The specimen has elongate spines on the basais and short, central nodes on the radiais and first interradiais. Two Upper Burlington species, G. tuberculosus and G. typus, also have these characteristics. Lane and DuBar (1983) assigned Nada material to the former because of its larger number of interradiais. However, they also mentioned that the original differences in the definition of these two species are in the arms and the tubular appendages, both of which are not preserved in the current specimen. Materials examined.— USNM 312168.

94 Occurrence.“ Upper Burlington Limestone, Burlington, Iowa, Pike Co., Missouri; Nada Memeber of the Borden Formation, Morehead, Kentucky at localiQr 1.

Order Monobathrida Moore and Laudon, 1943 Suborder Compsocrinina Ubaghs, 1978 Superfamily Carpocrinidae de Koninck and LeHon, 1854 Family Batocrinidae Wachsmuth and Springer, 1881 Genus Uperocrinus Meek and Worthen, 1865 Type species.— Actinocrinus pyriformis Shumard, 1855; by original designation. Uperocrinus pyriformis (Shumard, 1855) Figure 5.2.3-5.2.6 Actinocrinus pyriformis Shumard, 1855, p. 192, PI. A, figs. 6a, 6b; 1860, PI. 2, fig. 8; Bassler and Moodey, 1943, p. 721. Actinocrinus pyriformis var. rudis Meek and Worthen, 1861, p. 131; Bassler and Moodey, 1943, p. 721 Actinocrinus (Uperocrinus) pistiliformis Meek and Worthen, 1865, p. 153; Bassler and Moodey, 1943, p. 721 Batocrinus pyriformis (Shumard, 1855). Meek and Worthen, 1873, p. 375, PI. 5, fig. 5; Keyes, 1894, p. 182, PI. 23, fig. 7; Bassler and Moodey, 1943, p. 721. Lobocrinus pyriformis (Shumard, 1855). Wachsmuth and Springer, 1897, p. 437, PI. 31, figs. 3a-3e; Bassler and Moodey, 1943, p. 721; Wolf, 1979, p. 151, Fig. 2.i; Webster, 1986, p. 190. Uperocrinus pyriformis (Shumard, 1855). Bassler and Moodey, 1943, p. 721; Moore and Laudon, 1944, p. 195, PI. 76, fig. 24; Laudon, 1948, PI. 2; Lane, 1963, p. 928, Fig. 5; Webster, 1973, p. 264; Haugh, 1975a, p. 485, PI. 3, fig. 3; 1975b, p. 267, Fig. 5.B; Lane in Moore and Teichert, 1978, p. T471, Fig. 276.3;

95 Lane and Dubar, 1983, p.118, Rg. 3.0; Le Menn, 1985, p. 180, Fig. 74.B; Webster, 1986, p. 316; 1988, p. 164; Baumiller, 1990, p. 399, Rg. 1 Diagnosis.— Calyx much higher than wide, higher than the tegmen, sides strongly concave; basais and radiais high, plates smooth; tegmen plates conspicuously nodose; arms twenty ; the width of the CD interray slightly wider than other interrays. Description.— Calyx large and high, cone shaped, strongly concave, cylindrical until the top of radiais, then expanding abruptly to distal extremities; base truncate. Basais three, hexagonal, wider than high, truncate at base and sometimes with minor ridge around proximal edg.t. Radiais five, large, much higher than wide, hexagonal in form; two primibrachials and two secundibrachials, much smaller than radiais; primibrachials quadrangular; primaxils pentagonal, usually larger than primibrachials. Normal interray narrower than CD interray; interradiais numerous, not in contact with tegmen; first interradial large, heptagonal in form; other interradiais much smaller with various forms. Primanal large, similar to radiais in form; second range in posterior interray much smaller, not in contact with tegmen.

Tegmen highly cone shaped, plates conspicuously nodose; sutures distinct; anal tube stout, long and central, gradully tapering distally. Arms twenty; arm openings vertical slit-like, directed obliquely upward. Columnals unkown. Discussion.- -Lane (1958) distinguished two groups within the genus Uperocrinus. The representatives of the first group have a gently convex dorsal cup and tegmen. The second group consists of species having a dorsal cup and tegmen with distinctly concave sides. The specimens assigned to U. pyriformis undoubtedly belong to the second group. U. pyriformis was initially described fit>m the Burlington Limestone of Iowa, Missouri and

96 minois. It is a distinctive and common species in the Upper Burlington Limestone. Lane and DuBar (1983) described one specimen of this species from Morehead, Kentucky. They pointed out that unlike many otlier species of Uperocrinus, U. pyriformis may have the interradial areas of the calyx completely arched over by frxed brachials and not in contact with tegmen plates. Eight new specimens o f U. pyriformis were recovered in this study, and this material confirms the Lane and DuBar (1983) identification. Material examined,- OSU 50360, 50358, 50361, 50354, 50356, 50355, 50359, 50357, USNM 312175. Occurrence.--Burlington Limestone in Iowa, Missouri and Illinois; Nada Member of the Borden Formation, Morehead, Kentucky.

Uperocrinus acuminatus new species Figure 5.2.8, 5.2.9, 5.2.11 Diagnosis.— Calyx higher than wide; calyx higher than the tegmen, sides slightly concave, plates flat and smooth; basal circlet high, tapering proximally and truncated obliquely at the base; tegmen smooth and low cone shaped; anal tube subcentral; CD interray conspicuously wider than the normal interray. Description.— Size of calyx small for genus, calyx cone-shaped, base obliquely truncated and tapering proximally, height of basais approximately same size as radiais; arms grouped but not lobate; aboral cup smooth; plate sutures distinct. Basais three, equal in size, as high as radiais, non-cylindrical, tapering proximally, 25-30 percent of height of aboral cup. Radiais five, heptagonal in form, a little wider than basais, largest plates of calyx, approximately 30 percent of aboral cup height.

97 Primanal approximately same size as radiais, second range in the posterior with three much smaller plates; third range with three or four smaller plates may or may not be in contact with tegmen. Normal interrays narrower than CD interray, fîrst interradial hexagonal, second and third ranges with numerous small plates, may or may not be in contact with tegmen. First primibrachial hexagonal, wider than high; second primibrachial axillary, pentagonal, smaller than first primibrachial, wider than high; first and second secondibrachials approximately the same size as second primibrachials; first tertibrachials small, last fixed brachials; arm openings elliptical, higher than wide, directed obliquely upward.

Tegmen low conical, plates flat and smooth; anal tube high and slender, central or subcentral toward the CD interray. Arms 18, foiu" paired arms each ray except for A ray that has only 2 arms. Free arms not known. Column unknown. Discussion.-- This new species differs from other species in Uperocrinus by having a relatively high and slender basal circlet that tapers proximally and by having flat and smooth calyx plates. The nearest species is U. pyriform is that has robost and cylindrical basais, nodose tegmen plates and a larger size. Another similar species is U. aequibrachiatus (McChesney) that also has smooth tegmen plates both on the tegmen and the calyx. However, it differs firom the new species by having lobate arm bases and non­ tapering, much lower basais. The new species is also similar to U. hageri (McChesney) by having tapering basais and smooth cup plates, but the latter has a lower and convex aboral cup and lower basais and radiais. Uperocrinus acuminatus n. sp. has characteristics of both Uperocrinus groups identified by Lane (1958) and described above. It has a concave-sided aboral cup, a convex

98 tegmen, and high and tapering basal circlet. It is probably closer to the second subgroup, if the smaller size is ignored. Lane and DuBar (1983) described two individuals (USNM 312172, 312173) collected fiom the locality 1 that are individuals of this new species. However, they designated them as Eretmocrinus calyculoides (Hall), which differs from the new species by having much lower and non-tapering basais and a much lower aboral cup. Therefore, these two specimens should be designated as a new species. Five additional specimens have been collected during this investigation. Etymology.— The species name acuminatus is Latin, referring to the tapering and pointed basal circlet. Materials examined.—OS\J 50366 is designated as the holotype. OSU 50363, 50367, 50365, 50364, 50362, USNM 312172, and USNM 312173 are the paratypes. Occurrence.— Nada Member of the Borden Formation, Morehead, Kentucky, at localities 1. 2 and 6. Measurements. See Table 5.2

Calyx Aboral Calyx Basal Basal Radial Radio Specimen height cup width plate plate plate plate height (A-CD) height width height width

MK-15 23.5 17.2 — 4.5 3.8 4.6 3.1

MK-5 — — 17.8 — — 3.9 2.5

MK-7 26.7 20.1 — 4.1 3.8 5.7 3.9 MK-16 19.2 14.2 12.4 3.2 2.8 3.9 3.1

MK-19 21.3 16.7 14.5 3.6 3.4 4.1 3.2

MK-170 23.2 15.6 — 4.0 3.8 5.1 4.1

Table 5.2. Measurements of Uperocrinus acuminatus (in mm).

99 Genus Eretmocrinus Lyon and Casseday, 1859 Type species.—Eretmocrinus magnificus Lyon and Casseday, 1859; by monotypy

Eretmocrinus corbulis (Hall, 1861) Figure 5.2.7, 5.2.10, 5.3.1 Actinocrinus corbulis Hall, 1861a, p. 265; 1861b, p. 1; Bassler and Moodey, 1943, p. 4-56. Eretmocrinus corbulis (Hall, 1861). Keyes, 1894, p. 175, PI. 23; Wachsmuth and Springer, 1897, p. 399, PI. 36, figs. 5, 6; Bassler and Moodey, 1943, p. 456; Laudon, 1973, p. 28, Fig. 4; Webster, 1977, p. 79; Lane, 1958, p. 163, PI. 8, fig. 8. Diagnosis.— Basais very short and expanded laterally, plates, especially the calyx plates, strongly convex and nodose.

Description.— Calyx subglobose, approximately as wide as high, bowl-shaped; tegmen semicircular in outline, lower than the calyx; calyx plates convex and nodose; tegmen plates nodose; base truncate. Basais three, low, with large transverse nodes directed obliquely downward; the upper margin of basais deeply notched along the sutures; radiais five, wider than high, with large, pedal-like, transverse nodes directed a little downward; primibrachials two, nodose. Primanal same size or slightly larger than radiais with similar sculpturing, second range with three nodose plates, widest part of CD interray; third range with three plates much smaller and smoother. Regular interray narrower than CD interray, not in contact with tegmen; first interradiais large, heptagonal or octagonal in form, nodose, second interradiais may or may not exist.

100 Arms 16-20, long, biserial, expanded distally. Tegmen low cone-shaped, height far lower than cup, plates mildly to strongly nodose. Column unkown. Discussion.— Lane (1958) first synonymized Eretmocrinus cloelia with E. corbulis, which was confirmed by Kammer (personal communication, 1993). Judged firom the current specimens, the morphology of the ornament (mainly nodes) on the plates are not very constant and certain amount of variation should be expected. This species was previously known from the lower Burlington Limestone and the lower part of the upper Burlington Limestone at Burlington, Iowa. Material examined.- OSU 50369, 50371,50370,50368. Occurrence.— Lower Burlington Limestone and the lower part of the upper Burlington Limestone at Burlington, Iowa, Missouri; The Nada Member of the Borden Formation, Morehead, Kentucky at localities 1,2 and 4 .

Family Coelocrinidae Bather, 1899 Genus Aorocrinus Wachsmuth and Springer, 1897 Type species.— Dorycrinus immaturus Wachsmuth and Springer in Miller 1889; by original designation. Aorocrinus nodulus new species Figure 5.3.2-5.3.7, 5.4.1, 5.4.2, 5.5.11 Aryballocrinus whitei Lane, 1983, p. 117, figs. 3J, P. Diagnosis.— Calyx low bowl shaped; rays lobate; calyx plates very convex with depressed sutures; tegmen flat except for the convex oral plates; two arms in each ray.

101 Description.- Calyx low bowl shaped; tegmen flat, lobate at arm openings; calyx plates very convex with depressed sutures, without sculpture; tegmen plates flat or mildly convex. Basais three, small, nearly hidden in side view, proximally truncated. Radiais five, much larger than basais, strongly nodose, heptagonal in form, approximately as wide as high, in contact with first primibrachial and first interradial above. Primanal hexagonal, slightly larger than the radiais, second range with three smaller hexagonal plates; fourth range with three even smaller plates; one or two additional ranges of very small plates lead to an eccentric, subcircular anal opening that is separated by one medium-sized plate from the large, very spinose, centrally or subcentrally positioned CD oral plate; CD interray wider than normal interrays. Normal interrays in contact with tegmen, slightly narrower than the CD interray; first range of interradiais with hexagonal plate, slightly smaller than radiais, second range with two smaller plates. First primibrachials hexagonal or quadrangular, wider than high, second primibrachial much smaller, axillary; first secundibrachial small, last fixed brachial; arm facets directed obliquely upward, horseshoe shaped; arm opening elliptical, higher than wide. Tegmen approximately flat except for the CD oral; CD oral large, strongly nodose, centrally or subcentrally positioned, surrounded by six smaller oral plates and one CD interradial plate above the anal opening. Arm trunk lobate, free arms and column unknown. Discussion.- -Aorocrinus nodulus n. sp. differs from all other species of the genus by having very convex calyx plates and a very low bowl-shaped calyx. Aorocrinus parvus (Shumard) has a very similar calyx morphology. However, it differs firom the new species

102 by having a more conical calyx, smooth calyx plates, more ranges (4-5) of anal plates above the primanal and a slightly larger calyx size. Another similar species is A. unicornis that also has nodose calyx plates and a relatively flat tegmen. It differs from the new species by having a robust spine on its CD oral plate and by having a different interradial plate pattern. Its first interradial is large and followed by two very small and narrow plates, whereas in the new species the corresponding plates are about the same size. A. elegans, another similar species, differs from the new species by having a much higher, conical or subconical calyx. Another comparable species is Aorocrinus parvibasis Wachsmuth and Springer, but the difrerences are that the new species has larger tegmen plates and lobate arm trunks. Lane and DuBar (1983) described two individuals of this species collected from locality 1 and placed them in Aryballocrinus whitei . However, Aryballocrinus whitei differs from the new species by having a larger size, higher calyx, less protuberant brachial lobes, and smooth, very thin, calyx plates. This mistaken identification was due to the poor preservation of the two USNM specimens, which are totally crushed. Four new specimens provide the means by which to reassign this material to Aorocrinus nodulus n. sp.. Etymology.-The species name nodulus is from Latin, referring to the conspicuously convex calyx plates. Materials examined.— OSU 50373 is designated as the holotype, OSU 50375, 50374, 50372 , USNM 312169, USNM 312170 are paratypes. Occurrence.— Nada Member of the Borden Formation, Morehead, Kentucky at localities 1, 3 and 6. Measurements. See Table 5.3

103 Calyx Aboral Calyx Basal Basal Radial Radial Primanal Primanal h e i^ t cup width plate plate plate plate length width Specimen height (A-CD) height width height width

MK-6 7.9 6.5 11.4 0.6 — 2.1 2.6 2.1 2.5

MK-25 5.6 4.7 9.2 — — 2.1 2.6 1.8 2.1 MK-27 7.2 5.6 9.7 0.3 2.1 2.0 2.8 1.9 2.1

MK-89 9.8 6.7 — 0.5 3.1 2.9 3.6 2.5 2.4

Table 5.3. Measurements of Aorocrinus nodulus (in mm).

Genus Dorycrinus Roemer, 1854 Type species.—Dorycrinus mississippiensis Roemer, 1854; by monotypy Dorycrinus quinquelobus (Hail, 1860) Actinocrinus quinquelobus Hall, 1860, p. 15, Unnum. text-fig; 1872, Pl.IH-a, figs. 18-20; Bassler and MocKiey, 1943, p. 440. Dorycrinus quinquelobus (Hall, 1860). Wachsmuth and Springer, 1897, p. 460, PI. 42, figs. 7-9; Bassler and Moodey, 1943, p. 440; Laudon, 1948, PI. 2; 1973, p. 30, Fig. 1; Webster, 1973, p. 118; Haugh, 1975, p. 267, Figs. 4.B; 5.10; 6.5; Webster, 1977, p. 74; Ubaghs in Moore and Teichert, 1978, p. T194, Fig. 164.2; Lane and Dubar, 1983, p. 119, Fig. 3.1; Webster, 1986, p. 132; 1988, p. 79. Description.— Calyx medium in size, plates flat and smooth, or very mildly convex; basais three, wider than high, base truncate; radiais five, larger than the basais, a little wider than high, or about the same size; interradiais in contact with tegmen; anal opening eccentric, directed laterally; five spines on five brachials just above the arm facets plus one spine on the CD interray.

104 Discussion.- Lane and Dubar (1983) described this species from the Nada Member. The current species differs finom the other species of the genus by having a relatively higher and cylindrical basal citcieL This species was previously known from the uppermost zone of the Burlington Limestone from Burlington, Iowa (Laudon, 1973). Material examined.- USNM 312176. Occurrence.- Upper Burlington Limestone, Burlington, Iowa; Nada Member of the Borden Formation, Morehead, Kentucky at locality 1.

Genus Agaricocrinus Hall, 1858 Type species.— Agaricocrinus tuberosus Hall, 1858; subsequent designation (by Miller and Gurley, 1897).

Agaricocrinus stellatus (Hall, 1858) Figure 5.4.8, 5.4.9 Actinocrinus (Agaricocrinus)? stellatus Hall, 1858, p. 564, Fig. 97; Bassler and Moodey, 1943, p. 289.

Actinocrinus (Agaricocrinus) geometricus Hall, 1860, p. 56, Unnum. text-fig.; Bassler and Moodey, 1943, p. 289. Agaricocrinus stellatus (Hall, 1858). Wachsmuth and Springer, 1897, p. 508, PI. 38, figs. 7a-7e; Bassler and Moodey, 1943, p. 289; Ehlers and Kesling, 1963, p. 1030; Webster, 1973, o. 42. Description.— Calyx conical or hemispherical; rays prominently lobate; basal circlet strongly concave, extremely low, both basais and radiais not visible from the side view; calyx plates flat and smooth; CD interray much wider than other normal interrays, first interprimibrachial large, elongate, followed by two very small, narrow plates between arm bases; tegmen low conical, tegmen plates nodose, CD oral extremely protuberant and forming the tip of the tegmen, surrounded by six much smaller plates; anal opening large

105 and relatively circular, below CD oral and separated by a couple of tiny plates; two arms in each ray; arm openings large, directing horizontally. Column and firee arms unknown. Discussion.— There have been three major reviews on Agaricocrinus since 1943. Bassler and Moodey (1943) recognized 41 valid species and 10 junior synonyms. Ehlers and Kesling (1963) considered 39 species to be valid. Webster and Lane (1987) discussed some general characteristics ofAgaricocrinus. Among them, the earlier species are smaller and have no more than ten arms. Meyer and Ausich (1997) reviewed many late Osagean species of the genus. There are two specimens ofAgaricocrinus from the Nada Member. The first one was assigned to A. stellus mainly because of its small size and its nodose tegmen plates. The second specimen is recognized as A. bullatus Hall because of its larger size, its lack of a nodose CD oral, and its cup plates visible from the side. A. stellus was previously known from the upper Burlington Limes'one in Quincy, Illinois; Burlington, Iowa. Materials examined.— One complete calyx (OSU 50377) Occurrence.— Upper Burlington Limestone, Quincy, Illinois, Burlington, Iowa; Nada Member of the Borden Formation, Morehead, Kentucky at locality 1.

Agaricocrinus bullatus Hall, 1858 Figure 5.4.4 Agaricocrinus bullatus Hall, 1858, p. 662, PI. 9, figs. 1 la ,l lb; Wachsmuth and Springer, 1897, p. 489, PI. 41, figs. 2a-2d; Bassler and Moodey, 1943, p. 285; Ehlers and Kesling, 1963, p. 1030; McLead, 1973, p. 244, PI. 1, fig. 6; Webster, 1973, p. 41; 1977, p. 32. Agaricocrinus pentagonus Hall, 1860, p. 57, Unnum. text-fig.; Whitfield, 1893, p. 25, PI. 2, figs. 17, 18; Keyes, 1894, p. 167, PI. 22, fig. 9; Bassler and

106 Moodey, 1943, p. 285. Agaricocrinites bullatus (Hall, 1858). Mocre and Laudon, 1942, p. 74, Fig. 4.c; 1943, p. 141, Pl. 12, fig. 4; 1944, p. 195, Pl. 76, fig. 14; Webster, 1973, p. 41. Discussion.— The single specimen assigned to this species is an obliquely compressed specimen with a Platyceras sp. on the tegmen. Some plates are missing. A similar species is A. convexus (Hall), the aboral cup of the current species, however, is not convex. This is one of the two «species ofAgaricocrinus firom the Nada Member. See the discussion of the previous species for species designation. Material examined.-Onc calyx, somewhat crushed (OSU 50378). Occurrence.— Upper Burlington Limestone, Burlington, Iowa; Nada Member of the Borden Formation, Morehead, Kentucky at locality 5.

Superfamily Periechocrinacea Bronn, 1849 Family Actinocrinitidae Austin and Ausim, 1842 Subfamily Actinocrinitinae Austin and Austin, 1842 Genus Discocrinus new genus Type Species.- Discocrinus protuberatus new genus, new species Diagnosis.— Calyx very low bowl shaped, almost disk shaped; very low tegmen; very small basais, barely visible from the side view; radiais strongly nodose or spinose, interrradiais mildly nodose; tegmen plates small, flat and smooth; CD interray larger than the other interrays.

Description.—Sq& species description below. Discussion.— Brower (1967) recognized four subgroups in the highly diversified family Actinocrinitidae. Ubaghs (1978) formalized these four divisions into subfamilies.

107 The current specimen clearly belongs ft) the subfamily Actinocrinitinae because of its protuberant brachial lobes and its aboral cup plate pattern. Ubaghs (1978) recognized seven genera in the subfamily Actinocrinitinae. The new genus distinguishes itself from all seven genera by having a much lower, almost disk-like calyx, spinose radiais and primanal, extremely protuberant brachial lobes that incorporated some second- or third-range interradiais into the flaring lobes. Blairocrinus resembles the new genus in terms of its lower calyx and the arm opening number, but it clearly differs from the new genus by having a much more stout anal tube, much larger tegmen plates, and smooth calyx plates. Abactinocrinus resembles the new genus by its highly protuberant brachial lobes and smaller tegmen plates, but it differs by its high conical shape, arm number (two in each ray instead of four), smooth radiais and its undifferentiated tegmen plates. Sampsonocrinus resembles the new genus by its highly protuberant brachial lobes, relatively low calyx, many plated tegmen, but it differs by its smooth calyx plates, more distinct basais and larger basal circlet. Actinocrinites and Diatorocrinus have much more conical calyxes and much larger size. Aacocrinus has a more conical calyx and smooth tegmen plates. Steganocrinus has distinct stellate calyx plates, one to two arm openings per ray, and a smooth tegmen composed of much larger plates. Brower (1967) proposed two lineages within this subfamily. The first one is represented by Actinocrinites, Aacocrinus, and Blairocrinus; the second is represented by Abactinocrinus, Sampsonocrinus and Steganocrinus. Discocrinus n. gen. is probably more closely allied with the second lineage because of its small, plated but differentiated tegmen and extremely protuberant brachial lobes. Etymology.— The generic name Discocrinus is Latin, referring to the almost disk­ like shape of its calyx. Ocurrence.— Middle Osagean, Mississippian; Nada Member of the Borden Formation, from Morehead, Kentucky

108 Discocrinus protuberatus, new species Figure 5.1, 5.4.6, 5.4.7 Diagnosis.— See generic diagnosis above. Description.— Calyx with very low bowl-shaped aboral cup; tegmen flat or very low cone shaped; rays lobate, prominantly protuberant, incorporating some second range or third range interradiais into the lobes; calyx plates variously nodose; tegmen plates smooth and generally much smaller than the calyx plates (Fig.5.1). Basais three, very small, almost fused, barely visible from the side view; basal circlet truncated proximally. Radiais five, largest plates of the calyx, variable in size; hexagonal or heptagonal in form, in contact with first primibrachial and first interradial; incomplete radial circlet with insertion of the primanal. Primanal hexagonal or heptagonal, same size and shape as radiais, conspicuously nodose; second range with two mildly nodose plates (one large, one small), other anals smooth and flat, variable in size and number; CD interrays wider than normal interrays; anal plates in wide contact with tegmen. Normal interrays much '.arrower than CD interray, in very narrow contact with tegmen, having three ranges of plates (1-2-2), much smaller than radiais, variable in size and shape; EC and DE interrays having more than four interradiais. First primibrachial quadrangular, wider than high; second primibrachial axillary, pentagonal in shape, approximately the same size as primibrachials; first secundibrachial pentagonal in shape, last fixed brachial; radial facets directed obliquely upward. Tegmen flat except for the anal opening portion; plates flat and smooth, very small, orals and ambulacrals differentiated; anal opening eccentric toward CD interray. Four arm openings each ray.

109 Column and free arms unknown. Discussion. —Steganocrinus pentagonis is a similar species in that it has a very low calyx and flat tegmen. However, it differs from the new species by having stellate cup plates, one to two arm openings on each ray, larger tegmen plates and a more stout anal tube. Etymology.— The species name protuberatus is Latin, referring to the protuberant arm trunks of the species. Materials examined.— The only known specimen, OSU 50379, is designated as holotype. Occurrence.— Nada Member of the Borden Formation, Morehead, Kentucky at locality 3. Measurements. See Table 5.4.

Calyx Aboral Calyx Basal Basal Radial Radial Primanal Primanal height cup width plate plate plate plate length width Specimen height (A-CD) height width height width

MK-10 9.1 7.2 13.4 0.2 2.7 2.6 2.8 2.2 2.8

Table 5.4. Measurements of Discocrinus protuberatus (in mm)

110 1 cm

C D

Figure 5.1 The aboral cup structureDiscocrinus of protuberatus showing the five rays and the anal plates that are grouped with C ray.

I l l Suborder Glyptocrinina Moore, 1952 Superfamily Platycrinitaceae Austin and Austin, 1842 Family Platycrinitidae Austin and Austin, 1842 Genus Platycrinites Miller, 1821 Type species.—Platycrinites laevis Miller, 1921; by subsequent designation (Meek and Worthen, 1865) Platycrinites glyptus (Uailr 1861) Figure 5.4.5, 5.4.10 Platycrinus glyptus Hall 1861, p. 16; Wachsmuth and Springer, 1885, PI. 7, fig. 5; 1897, p. 693, PI. 67, fig;-. 4,5; Bassler and Moodey, 1943, p. 620.

Platycrinites glyptus (Hall, 1861). Bassler and Moodey, 1943, p. 620; Laudon, 1937, p. 31, Fig. 6; Webster, 1977, p. 138. Diagnosis.— Calyx low to medium bowl-shaped; basal circlet relatively low, base truncate; radial height equal to width; aboral cup plates sculptured with ridges consisting of small nodes, radiais traversed by two diagonal ridges from the facets to the proximal margin of the plates. Description.— Calyx medium in size for Platycrinites. Distinctive aboral cup plate ornamentation with variable nodes converging into ridges; tegmen flat, consisting of numerous small convex plates. Basais three, much wider than high, sculptured with series of horizontal ridges parallel to the proximal margin of the plates; basal circlet relatively low, about 20% of the aboral cup height; base truncate, proximal column in basal concavity. Radiais five, quadrangular in shape, width approximately equal to height, ridges parallel to the margins of the plates plus two diagonal ridges initiating from the facets and

112 meeting the parallel ridges at two proximal comers of the radial; radial circlet about 80% of aboral cup height Tegmen flat, consisting of numerous small nodose plates. First primibrachial axillary; second secundibrachial and tertibrachial (also quartibrachial if present) axillary; biserial brachials usually starting from the tertibrachials. Arms numerous, eight in each ray at least. Column helically twistied.

Discussioru— Platycrinites glyptus belongs to Flatycrinities sculptus species group of Wachsmuth and Springer (1897), which includes P. sculptus, P. glyptus, P. sqffordi, P. scobina, P. parvinodus, and P. peculiaris. Among them, P. sculptus, P. glyptus, and P. sqffordi are much more similar to each other. The current specimens differ from P. sqffordi and P. sculptus by having smaller size, equal-sided radiais, and lower basal circlet. This species was previously known from the upper Burlington Limestone, Burlington, Iowa and Hendrson Co., Illinois. Materials examined.— One cmshed specimen (OSU 50380), two partially preserved individuals (OSU 503F1,50382) and numerous isolated plates. Occurrence.— Upper Burlington Limeston, Burlington, Iowa and Henderson Co., Illinois; Nada Member of the Borden Formation, Morehead, Kentucky at localities 1, 6 and

8.

Platycrinites planus (Owen and Shumard, 1850) Figure 5.4.3 Platycrinus planus Owen and Shumard, 1850, p. 57, PI. 7, figs. 4a-4c; 1852, p. 587, PI. 5A, fig. 4a; Wachsmuth and Springer, 1897, p. 668, PI. 69, figs. 2a-2d; Weller, 1900, p. 28, Fig. 10; Bassler and Moodey, 1943, p. 625. Platycrinites planus (Owen and Shumard, 1850). Meek and Worthen, 1873, p. 452,

113 Pl. 3, figs. 5a-5c; Bassler and Moodey, 1943, p. 625; Laudon, 1973, p. 31, fig. 6; Webster, 1977, p. 138; Ausich and Kanuner, 1990, p. 774; Webster, 1993, p. 94. Description.— Calyx bowl shaped, small in size, boundary between basais and radiais not distinct; both basais and radiais smooth and flat without any ornamentation; basal circlet tapering proximally, about one third of aboral cup height; radiais quadrangular, higher than wide, smooth and mildly convex; sutures between plates very indistinct; first primibrachials axillary; arms slender, at least eight in each ray. Discussion.— This species belongs to thePlatycrinites planus group of Wachsmuth and Springer (1897) that is characterized by fiat and smooth plates without any ornamentation. It differs firom other species of the group by having a very high basal circlet, very indistinct sutures, and slender arms. P. planus has been described from various horizons and locations of Lower Mississippian rocks (Bimlington Limestone, Burlington, Iowa; Button Mold Knob, Bullitt Co., Kentucky, and Keokuk Limestone, Newbloomfield, Missouri). Ausich and Kanuner (1990) revised the definition of this species and believed that it does not occm in any late Osagean strata. The current study concurs with this revision and considers this species to only exist in the Burlington Limestone of Middle Osagean Age. Four species of Platycrinites exist in the Nada Member. They are: P. glyptus, P. planus, P. tennuibrachiatus and P. incomptus. P. glyptus and P. tennuibrachinatus both have ornamentation on the basalf and radiais. The former has cup plates sculptured with ridges consisting of small nodes. The latter has the characteristic rugose-like ornamentation resulting from pitted nodes and ridges. Both P. planus and P. incomptus lack plate sculpture, but unlike P. planus, P. incomptus has a much lower basal circlet. Materials examined.— One single specimen slightly crushed (OSU 50383).

114 Occurrence.— Lower and upper Burlington Limestone, Burlington, Iowa, Louisiana, Missouri; Button Mold Knob, Louisville, Kentucky; Keokuk Limestone, New Bloomfield, Missouri; Nada Member of the Borden Formation, Morehead, Kentucky at locality 2.

Platycrinites tenuibrachiatus Meek and Worthen, 1869 Platycrinites tenuibrachiatus Meek and Worthen, 1869, p. 168; 1873, p. 450, PL 3, fig. 4; Bassler and Moodey, 1943, p. 628; Lane and Dubar. 1983, p. 119, Fig. 3.E; Webster, 1988, p. 135. Platycrinus tenuibrachiatus (Meek and Worthen, 1869). Wachsmuth and Springer, 1897, p. 687, FI. 70, figs. 7,8; Bassler and Moodey, 1943, p. 628. Discussion.- -USNM 312177 was described by Lane and DuBar (1983). It was assigned to P. tenuibrachiatus by virtue of having a flat basal circlet, upright radiais, and the characteristic rugose-like sculpturings resulting from pitted nodes and ridges. No additional specimens of this species were found during the present study. See discussion of P. planus for comparisons to other Nada MemberPlatycrinites. Materials examined.— USNM 312177. Occurrence.— Upper Burlington Limestone, Burlington, Iowa; Nada Member of the Borden Formation, Morehead, Kentucky at locality 1.

Platycrinites incomptus? (White, 1893) Platycrinus incomptus White, 1863, p. 503; Wachsmuth and Springer, 1897, p. 664, PI. 67, fig. 6, PI. 71, figs, 1-3. Platycrinites incomptus (White, 1863). Meek and Worthen, 1873, p. 459, PI. 3, fig. 7; Bassler and Moodey, 1943, p. 622; Laudon and Severson, 1953, p. 532, PI. 54, fig. 9; Laudon, 1973, p. 31, fig. 6; Lane and Dubar, 1983,

115 p. 119, Fig. 3.M. Discussion.— Lane and DuBar (1983) described one smoothly plated specimen (USNM 312178) with a low basal circlet. The specimen is somewhat crushed and the upper edges of some radiais are broken. The tegmen was not preserved. The placement of this specimen into a species is admittedly difRculL Therefore the species name is uncertain. No additional specimens of this species were found during the present study. This species was previously known from the Burlington Limestone, Burlington, Iowa. Materials examined.- -USNM 312178. Occurrence.— Burlington Limestone, Burlington, Iowa; Nada Member of the Borden Formation, Morehead, Kentucky at locality 1.

Subclass Disparida Moore and Laudon, 1943 Superfamily Belemnocrinacea Miller, 1883 Family Synbathocrinidae Miller, 1889 Genus Sy/i^arAocri/M/s Phillips, 1836 Type species.— Synbathocrinus conicus Phillips, 1836; by monotypy. Synbathocrinus wortheni Hall, 1858 Figure 5.5.1-5.5.4 Synbathocrinus wortheni Hall, 1858, p. 560, PI. 9, fig. 9; Wachsmuth and Springer, 1885, PI. 4, figs. 9-11; Springer, 1923, p. 19, PI. 5,fig. 8; Bassler and Moodey, 1943, p. 697; Kesling and Smith, 1963, p. 195; Webster, 1973, p. 249. Symbathocrinus wortheni [sic] (Hall, 1858). Keyes, 1894, p. 206, PI. 25, fig. 15. Diagnosis.— Aboral cup high cone shaped, small sized, low basal circlet, about 1/3 of the cup height; radialrradial sutures flush or depressed; horizontal notch exists between radiais and first primibrachials.

116 Description.— Crown narrow, cylindrical. Aboral cup Qrpically with perfect pentameral symmetry except for very small anal X; medium bowl shape. Base is truncate; sutures are flush or depressed. Basais three, relatively low, about half the height of radiais, basal circlet tapering proximally. Radiais five, large, trapezoidal in shape, uniform in size. Anal X slender and elongate, only extra plate in CD interray, extending distally to top of the adjacent first primibrachials. Arms five, long and slender, atomous and uniserial; first primibrachials as large as radiais; a horizontal notch usually present between the radiais and first primibrachials. Colunrn unknown. Discussion.- The specimens recovered during this study fit all the previous illustrations and descriptions of the species. When Hall (1858) first proposed this species, he also distinguished it from another similar species, i.e., Synbathocrinus swallovi; the major difference was that the latter has much shorter basais. The basais of the current specimens are clearly higher than those ofS. swallovi illustrated by Hall. This species was previously known from the Burlington Limestone, Jersey Landing, Illinois. M aterials examined.— Two well-preserved specimens OSU 50384 and 50385. Occurrence.— Burlington Limestone, Jersey Landing, Illinois; Nada Member of the Borden Formation, Morehead, Kentucky at locality 2.

Superfamily Caleocrinacea Meek and Worthen, 1869 Family Calceocrinidae Meek and Worthen, 1865 Genus Halysiocrinus Ulrich, 1886 Type species.— Cheirocrinus dactylus Hall, 1860; by original designation. Halysiocrinus dactylus ? (Hall, 1860)

117 Cheirocrinus dactylus Hall, 1860, p. 123, Figs. 1,2; Bassler and Moodey, 1943, p. 500. Halysiocrinus dactylus (Hall, 1860). Ulrich, 1886, p. 110; Springer, 1926, p. 95, P1.30, figs. l-3a; Bassler and Moodey, 1943, p. 500; Moore and Laudon, 1944, p. 145, Pl. 55, fig. 5; Moore, 1962, p. 33, Pl. 2, fig. 1; Fig. 7.1; Van Sant in Van Sant and Lane, 1964, p. 69, Fig. 25, no. 3; Good, 1968, Pl. 1, fig. 6; Webster, 1973, p. 145; 1977, p. 95; Moore and Lane in Moore and Teichert, 1978, p. T532, Fig. 326, nos. 4a, 4b; Webster, 1986, p. 165; Brower, 1987, p. 1001, Figs. 3.9; 4.7 to 4.9; 4.19 to 4.21; 1988, p. 24, Figs. 2-6; Brower, 1990, p. 301, Fig. 7.29 to 7.30; Webster, 1993, p. 66. Deltacrinus dactylus (Hall, 1860). Springer, 1923, p. 19, PI. 5, fig. 20; Bassler and Moodey, 1943, p. 500. Diagnosis.— Aboral cup adanally-abanally compressed; smooth plates; nodes absent on A and D radiais; four axil arms, no axillaries in main axil series after first brachial; E arm brachials not nodose, branching of the E arm unkown. Description.— Crown medium, recumbent on column; aboral cup medium, adanally-abanally compressed; aboral cup plates smooth, nodes absent on brachials. Basal circlet approximately twice as wide as high; three basal plates; elongate ligment groove along entire radial-basal articulation. Radial circlet widest proximally, subtrapezoidal in shape; A and D radiais occupy majority of radial circlet; each plate widens distally and proximally, nodes absent; E inferradial triangular along radial-basal articulation; E superradial forms entire distal margin of aboral cup and bears the E arm; anal X and anal sac unknown. Branching of normal lateral arms unknown; main axils well developed; first brachials non-axillary, slender, higher than wide.

118 Column unknown except for the triangular mark left on the specimen by the broken column.

Discussion.—There are only two species ofHalysiocrinus from the Burlington Limestone, i.e., H. dactylus which is the type species of the genus and H. wachsmuthi (Meek and Worthen). H. ventricosus was synonymized with H. dactylus by Springer (1926). The two species are very similar except that H. dactylus has its median ray arm (E- ray) bifurcating whereas the H. wachsmuthi E arm is atomous. Comparing the original descriptions and illustrations, the former seems to be a little larger than the latter. Because arms were only partially preserved in the current specimen, the specific designation is difficult. It is designated as H. dactylus ? because of its larger size. This species was previously known from the Burlington Limestone, Burlington, Iowa. Materials examined.— One calyx specimen without column. OSU 50386. Occurrence.— Upper Burlington Limeston, Burlington, Iowa; Nada Member of the Borden Formation, Morehead, Kentucky at locali^ 6.

Subclass Cladida Moore and Laudon, 1943 Suborder Cyathocrinina Bather, 1899 Superfamily Cyathocrinitaea Bassler, 1938 Family Cyathocrinitidae Bassler, 1938 Genus Cyathocrinites Miller, 1821 Type species.— Cyathocrinites planus Miller, 1821; by subsequent designation (Wachsmuth and Springer, 1880). Cyathocrinites iowensis (Owen and Shumard, 1850) Figure 5.5.5, 5.5.6 Cyathocrinus iowensis Owen and Shumard, 1850, p. 63, PI. 7, figs. 11a-11c; 1852, p. 591, PI. 5-A, figs. lla -llc ; Keyes, 1894, p. 207, PI. 25, fig. 11; Wachsmuth

119 and Springer, 1885, PI. 5, figs. 7, 8; Bassler and Moodey, 1943, p. 392. Cyathocrininus iovensis [sic] Owen and Shumard, 1850. Wachsmuth and Springer, 1885, pi. 5, figs. 7, 8. Cyathocrinites iowensis (Owen and Shumard, 1850). Bassler and Moodey, 1943, p. 392; Ausich et al., 1994, p. 360; Kammer and Ausich, 1996, figs. 7, 8. Diagnosis." Aboral cup bowl shaped, medium height; basais swollen or tumid; cup plates smooth, no sculpturing; arm facets horseshoe shaped, medium size. Description.- -Calyx bowl shz^ied, aboral cup plates nodose; infrabasals five, very small, only comers visible from side view; basais five, large, hexagonal or heptagonal in shape, distinctly nodose, basal circlet about 50 percent of the aboral cup height; radiais five, about the same size as basais; arm facets large, horseshoe-shaped, half or less than half of the width of radiais, directed obliquely upward; anal X, the only anal plate, a little smaller than radiais, pentagonal or hexagonal in shape, directly above CD basal; anal sac and tegmen plates unknown; column circular in section; firee arms unknown. Discussion." There was a major revision of this species by Kammer and Ausich (1996). Cyathocrinities malvaceous, C. divaricatus, C. rotundatus, C. viminalis, C. parvibrachiatus, C. hamiltonensis, C. nodosus, C. brevisacculus, C. opimus, and C. gurleyi were all placed in synonymy with C. iowensis. The current specimen was assigned to C. iowensis because of its smooth plates and swollen basais. Another species that is similar to the current species is C. gilebsi (Wachsmuth ans Springer). However, it has smaller infrabasals, larger arm facets (larger than half of the width of the radiais), and much more robust arms. According to the revised definition, this species has numerous occurrences and has a long stratigraphie range. Previously known occurrences include Burlington Limestone, Burlington, Iowa; Keokuk Limestone, Keokuk and Bonaparte, Iowa, Hamilton, Illinois; lower part of the Warsaw Formation, Meramec River Ridge,

120 Kirkwood, Missouri; Edwardsville Formation, Crawfordsville, Indian Creek and Monroe Reservoir, Indiana. Materials examined.— One compelete calyx, a little crushed (OSU 50387). Occurrence.— Burlington Limestone to Warsaw Limestone, Iowa, Illinois; Nada Member of the Borden Formation, northeastern Kentucky at locality I.

Suborder Dendrocrinina Bather, 1899 Superfamily Mastigocrinacea Jaekel, 1918 Family Mastigocrinidae Jaekal, 1918 Genus Atelestocrinus Wachsmuth and Springer, 1886 Type species.— Atelestocrinus delicatus Wachsmuth and Springer, 1866; by subsequent designation (Miller, 1889). Atelestocrinus kentuckyensis new species Figure 5.5.8, 5.5.9 Diagnosis.— Radiais much higher than wide; two small, polygonal tegmen plates incorporated into the cup at A ray; A ray radial tear-drop shaped, much smaller than other radiais. Description.— Aboral cup medium sized, high, inverted bell shaped; radial plates five, roughly rectangular, approximately twice as high as wide; A-ray radial much smaller than the other radiais, tear-drop in shape, overlain by two even smaller tegmen plates that are incorporated into the cup; primibrachial preserved in E ray, non axillary, wider than high; radial facets plenary, declivate; basais, infrabasals, arms, and column unknown. Discussion.— The new si-ecies is known firom only a radial circlet with four arm- bearing radiais and one radial without a radial facet. Hence, it is assigned to Atelestocrinus, which is a rare Mississippian genus known only from three species and relatively few specimens. The new species differs from A. robustus Wachsmuth and

121 Springer and A. delicatus Wachsmuth and Springer by having radiais that are much higher than wide and by the absence of any anal plates. The only other species within the genus, A. indianesis, is from the Edwardsville Formation of the Borden Group in Indiana, and it is very similar to the new species in terms of the shape of the radiais and the absence of anal plates. However, it differs from the new species by having an A-ray radial without the teardrop shape, and it does not b?ve the two tegmen plates lying above it within the aboral cup. Moreover, the new species is larger than A. indianensis. Because A. kentuckyensis is older, it is probably the ancestor of A. indianensis and changed by elimination of the two A ray tegmen plates from the cup. Etymology.— The specifrc name kentuckyensis is derived from the state of Kentucky. This is the first occurrence of Atelestocrinus in the state of Kentucky. Materials examined.— The holotype is designated as OSU 50388; it has a complete radial circlet preserved. OSU 50389 is a paratype. Occurrence.— Nada Member of the Borden Formation, Morehead, Kentucky at localities 2 and 6. Measurements.See Table 5.5

Radial Radial A-radial A-radial Primibrach Primibrach Specimen plate plate plate plate height width height width height width MK-95 8.9 5.6 5.5 2.9 2.6 3.0

MK-98 8.2 4.7 — — 2.0 3.5

Table 5.5. Measurements of Atelestocrinus kentuckyensis (in mm).

Suborder Poteriocrinina Jaekel, 1918

122 Superfamily Erisocnnacea Wachsmuth and Springer, 1886 Family Graphiocrinidae Wachsmuth and Springer, 1886 Genus Holcocrinus Kirk, 1945 Type species." Graphiocrinus longicirrtfer Wachsmuth and Springer, 1890; by original designation.

Holcocrinus spinobrachiatus (HaïL, 1861) Figure 5.5.7 Scaphiocrinus spinobrachiatus Hall, 1861; Wachsmuth and Springer, 1886, p. 236; Bassler and Moodey, 1943, p. 584; Kirk, 1945, p. 520; Webster, 1973, p. 149. Poteriocrinus spinobrachiatus (Hall, 1861). Worthen, 1882, p. 20; 1883, p. 290, PI. 29, fig. 1; Bassler and Moodey, 1943, p. 584. Holcocrinus spinobrachiatus (Hall, 1861). Kirk, 1945, p. 520; Webster, 1973, p. 149. Diagnosis." Arms slender, with nodes at each brachial; primibrachial axillary, higher than wide.

Description." Calyx medium sized; aboral cup bowl shaped, plates convex or flat; infrabasals not visible in side view; basais medium sized, approximately 30 percent of cup height, wider than high, visible from the side; radiais large, approximately 70 percent of the cup height, with articular facets full width of plates; one primibrachial in each ray, axillary, higher than wide, constricted at mid length; arms ten, isotomous; brachials cuneate uniserial, slender, bearing one node or low spine in each; column pentagonal at proximal end; distal columnal and holdfast unknown.

Discussion." This species distinguishes itself from the other species of Holcocrinus by its higher primibrachials and the nodose arm brachials. A very similar species is Holcocrinus nodobrachiatus (Hall) that was discovered in Crawfordsville and Monroe Resevoir in Indiana (see Ausich and Lane, 1982). The difference is that the latter has a circular columnal, more robust arm brachials and radiais with rows of nodes on the

123 distal and proximal edges. Another similar species is H. sm ythi (Wright) that is present at Hook Head Co., Wexford, Ireland. It differs from the current species by having a much higher primibrachial, and its arm brachials do not have nodes. This species was previously known from the lower part of the Burlington Limestone, Burlington, Iowa. Materials examined.— One specimen (OSU 50390) with arms still attached; some of the aboral cup plates are not exposed. Occurrence.— Burlington Limestone, Burlington, Iowa; Nada Member of the Borden Formation, Morehead, Kentucky at locality 5.

Superfamily Scytalocrinacea Moore and Laundon, 1943 Family Scytalocrinidae More and Laudon, 1943 Genus Histocrinus Type species.— Poteriocrinus grandis Wachsmuth and Springer 1880; by original designation. Histocrinus sp. Description.— Aboral cup conical, high, bowl-shaped, medium to large size, plates smooth; basais five, higher than wide, pentagonal in shape; radiais wider than high, arm facets crescentic, peneplenary; anal plates not preserved; arms ten, relatively stout, with two primibrachs, first primibrach much wider than high, second primibrach pentagonal in shape; arm brachials cuneate uniserial with pinnules. Infrabasals, column and anal sac not preserved in this specimen. Discussion.— There are currently three species within Histocrinus. H. juvenis (Meek and Worthen) is the only Burlington species. It is extremely small, and its first primibrachial is higher than wide. H. graphicus (Miller and Gurley) has a smaller size, more slender arms and finely sculptured cup plates. H. coreyi (Worthen) is the most closely allied species with the current specimen. However, it has a definite atomous A ray

124 that was, unfortunately, not preserved in the current specimen. Therefore, the specific designation of the current specimen can not be determined. Materials examined.- -One specimen without infrabasals, a little crushed (OSU 50391). Occurrence.— Nada Member of the Borden Formation, Morehead, Kentucky at locality 3.

Subclass Rexibilia 2IittleI, 1895 Order Taxocrinida Springer, 1913

Superfamily Taxoctinacea Angelin, 1878 Family Taxocrinidae Angelin, 1878 Familily Taxocrinidae Angelin, 1878 Genus Taxocrinus Phillips in Morris, 1843 Type species.— Cyathocrinus? macrodactylus Phillips, 1841; by subsequent designation (Worthen in Meek and Worthen, 1866) Taxocrinus sp Figure 5.5.10 Discussion.— Two incomplete specimens (one is USNM 312184 from Lane and DuBar) exist for examination. Judging from the arm branching pattern, they clearly belong to the same species. Both have at least two primibrachials. One ray in specimen MK-85 displays three primibrachials. Arm branching is isotomous. It was assigned to Taxocrinus because of its arm branching pattern and the number of primibrachials. Because only part of the arm was preserved in the specimens, the specifrc designation carmot be determined. Material examined.— OSU 50392 and USNM 312184. Occurrence.— Nada Member of the Borden Formation, Morehead, Kentucky at locality 1.

125 Figure 5.2 -1, 2 Rhodocrinites barrisi (Hall, 1861). 1, OSU 50353, aboral view xl.5. 2, OSU 50352, lateral view of the aboral cup, xl.5. 3,4,5, 6, Uperocrinus pyriform is (Shumard, 1855). 3, OSU 50360, lateral view, xl.5. 4, OSU 50358, lateral view, xl.5. 5, 6, OSU 50355. 5, lateral view (E ray), xl.5. 6, lateral view (E ray), xl.5. 8, 9, 11, Uperocrinus acuminatus new species. 8, OSU 50366, holotype, lateral view (B ray), x2. 9, OSU 50364, paratype, lateral view, x2. 11, OSU 50366, lateral view (D ray), xl.5. 7, 10, Eretmocrinus corbulis (Hall, 1861), OSU 50368. 7, lateral view (D ray), xl.5. 10, lateral view (B ray), xl.5.

12 6 Figure 5.2 1 2 7 Figure 5.3-1, Eretmocrinus corbulis (Hall, 1861), OSU 50370, lateral view, x2.2, 3,4, 5, 6, 7, Aorocrinus nodulus new species. 2, 3, OSU 50373, holotype. 2, oral view, x4. 3, basai view, x4. 4, 6, OSU 50372, paratype. 4, basai view, x4. 6, oral view, x4. 5, OSU 50374, paratype, oral view, x4.7, OSU 50376, paratype, lateral view (CD interray), x4.

128 Figure 5.3 1 2 9 Figure 5.4 -1, 2, Aorocrinus nodulus new speices. 1, OSU 50376, paratype, lateral view (A ray), x4.2, OSU 50375, paratype, oral view x4. 3, Platycrinites planus (Owen and Shumard, 1850), OSU 50383, lateral view, x2.4, Agaricocrinus bullatus Hall, 1858, OSU 50378, lateral view (A ray), xl.5. 5, 10, Platycrinites glyptus (Hall, 1861). 5, OSU 50381, lateral view, x2. 10, OSU 50380, lateral view, x2. 6, 7, Discorinus protuberatus new species, OSU 50379, holotype. 6, oral view x2.7, basai view x2. 8,9, Agaricocrinus stellatus (Hall, 1858), OSU 50377. 8, oral view, xl.5. 9, basai view, xl.5.

130 Figure 5.4 1 3 1 Figure 5.5 - I, 2, 3,4, Synbathocrinus wortheni Hall, 1858. 1, 2, OSU 50384. 1, lateral view (CD interray), x 1.5. 2, lateral view (A ray), xl.5. 3, 4, OSU 50385. 3, lateral view (A ray), x l.5 .4, lateral view (CD interray), xl.5. 5 , 6, Cyathocrinites iowensis (Owen and Shumard, 1850), OSU 50387. 5, lateral view (CD interray), x l.5 .6, lateral view (A ray), xl.5. 7, Holcocrinus spinobrachiatus (Hall, 1861), OSU 50390, lateral view, xl.5. 8, 9, Atelestocrinus kentuckyensis new species, OSU 50389, holotype. 8, lateral view (CD interray), x4. 9, lateral view (A ray), x4. 10, Taxocrinus sp., OSU 50392, lateral view, xl.5. 11, Aorocrinus nodulus new species, OSU 50374, paratype, basai view, x4.

132 Figure 5.5 133 CHAPTER 6

PLATYCERATID GASTROPODS AND THEIR BIOSTRATIGRAPHIC AND PALEOECOLOGIC IMPUCATIONS

6.1. INTRODUCTION

The Paleozoic platyceratid gastropods have been extensively viewed as living on the tegmen of certain crinoids and having a coprophagous life style, but without doing any harm to the crinoid host, thus, a good example of commensalism (Keyes, 1890, 1892; Bowsher, 1955; Knight et al, 1960; Lane, 1973; Meyer and Ausich, 1983; Kluessendorf, 1983; Powers and Ausich, 1990). On the other hand, some recent works cast some doubts on the obligatory nature of this relationship (Rollins and Brezinski, 1988; Baumiller, 1990; Boucot, 1990).

The taxonomy of the platyceratids has been traditionally haunted by the great deal of variations of shell morphology, which are due to their sedentary habit of living on the crinoid tegmen. Mote than 300 Paleozoic species have been described, among them more than 35 are from the Mississippian rocks of North America (Keyes, 1892; Yochelson, 1969). However, the biologic meaning of these numerous species is probably questionable, because the aperture features, the topography of the shell surface and the general shell forms, which are the major definitive characteristics used in the classification, are heavily dependent on the topography and ornamentation of the crinoid tegmen to which it is attached. Although numerous plaQfceratid species have been described from the Mississippian, the group that has long, tubular spines has generally been overlooked.

134 Because the tubular spines on the shell surface are part of their own ontogenic development and are not influenced much by the morphology of the crinoid tegmen, it deserves more taxonomic attention than it receives. The specimens of the current study are the first reported Mississippian platyceratids with tubular spines east of the Illinois Basin, and they provide new information on the biostratigraphy and paleoecology of the Borden delta.

6.2. LOCATION AND GEOLOGICAL SETTING All specimens were collected from several sections of the Nada Member, Borden Formation of northeastern Kentucky, which is the western margin of the Appalachian Basin. The Deltaic nature of the Borden has been well established and the Nada Member is interpreted as the delta platform deposits and representing the end stage of the building-up of the Borden delta in this area (Chaplin, 1980; Lane and Dubar, 1983). The Borden Formation in northeastern Kentucky is considered environmentally equivalent of the Borden Group in Indiana and Illinois and the westward progradational nature of the Borden delta is also established (Lane andDuBar, 1983; Sable and Dever, 1991).

6.3. BIOSTRATIGRAPHY OF THE PLATYCERATIDS OF THE NADA Platyceratid gastropods have a history from the Middle Ordovician to Middle Permian (Bowsher, 1955; Knight et al., 1960), and they are one of the most common fossil groups encountered in the field, especially for many Devonian and Mississippian rocks. However, their biostratigraphic application has generally been deemed to be very limited. There are two main reasons for this: 1) there are very few constant and stable morphological features that can be used for their classification; 2) the characteristics that are used to designate the numerous species are so variable and unstable that it is commonly impossible to clearly distinguish between many of the species, thus resulting in a lot of

135 geologically long-lasting species. Nevertheless, the platyceratids with long, tubular spines, especially those from the Mississippian rocks, are very good biostratigraphic markers, a fact that has generally been overlooked. Spinose platyceratids apparently originated during the Early Devonian. Platyceras (Platyceras) dumosum Conrad and P. (P .) echinatum Hall are two representative species of this group. The typical pattern of spines for the Devonian platyceratids is that they are randomly scattered all over the shell surface (Fig. 6.1). When this group evolved into the Mississippian, the distribution of the tubular spines became more and more regular. Only two described species of spinose plaQfceratids are known from the Mississippian rocks, i.e., P. (P.) tribulosum White and P. (P.) biserialis Hall. Both of them have been found in the current study. They are characterized by their regular, longitudinal rows of tubular spines (See Systematics) (Fig. 6.2). These species were previously known from the standard Mississippian type section area of Iowa, Illinois and Missouri. They occur in the Burlington Limestone and until recently none was ever found in any other horizon (Hall, 1859; Meek and Worthen, 1868; Keyes, 1889, 1890a, 1890b, 1892; Shimer and Shrock, 1944). In addition to the two spinose species, the other two common Mississippian platyceratids, P. (P.) equilaterialis Hall and P. (Orthonychia) acutirostre (Hall), are also present in the Nada. However, they are long-ranging species and, thus, bear no significance in detailed stratigraphie correlation. Judged from the whole gastropod fauna, the Nada should be correlated with the Burlington Limestone in the Mississippian type section.

Although the general nature of the westward progradation of the Borden delta was established several decades ago (Swann et al, 1965; Lineback, 1969; Lane, 1973), the exact biostratigraphic evidence is not available until recently. Lane and Dubar (1983) studied a crinoid fauna from northeastern Kentucky and concluded that the Nada Member

136 1 cm

Figure 6.1 Devonian platyceratid with randomly-scattered spines on the shell surfaces. Spine bases are shown in the sketch.

137 of the Borden correlates with the upper Burlington Limestone o f the standard Mississippian section. Their crinoid specimens were collected from some of the same sections of the current study, and the platyceratid fauna is co-occurring with the crinoids. The biostratigraphic designation of the platyceratids is consistent with that of the crinoid fauna and, thus, provides another paleontological confirmation of the westward progradation of the Borden delta.

6.4. Autecology of platyceratids The autecology of the Paleozoic platyceratids is typically associated with a coprophagous life style on the crinoid tegmen, and numerous in situ specimens have been found from the Upper Ordovician through the Permian (Bowsher, 1955). Knight et al. (1960) incorporated this relationship into the definition of the family Platyceratidae. The obligate commensalism between crinoids and platyceratids have also been outlined by other authors (Lane, 1978; Meyer and Ausich, 1983; Powers and Ausich, 1990). In their definition of the family Platyceratidae, Knight et al. (1960) emphasized that ornamentation was only present in more primitive stocks but that it was gradually lost. Obviously, the tubular spines on some of the Devonian and Mississippian platyceratids were not taken into consideration. Nevertheless, these long, hollow, tubular spines are more constant and more stable characteristics than the apertural shapes, the longitudinal folds and sinuses and other features that are heavily dependent on the morphology of the host crinoids and have no homologous nature. There is only one specimen in the current Nada collection that has a platyceratid individual attached to the tegmen of a crinoid {Agaricocrinus sp.). This specimen is crushed, and the gastropod is firagmented. Apparently, it is one of these non-spinose platyceratids. The spinose platyceratids in the current study are characterized by having longitudinal rows of regular spines on the two lateral sides of the shell (P.tribulosum has

138 another row of spines on the dorsal, central side). The diameter of the spines is approximately 1.5 mm at the base, which is rather thick in terms of the small size of the whole shell. No complete spines were preserved. Because obvious tapering is not displayed at the end of the broken spines, which are about 4 mm long, the complete length of the spines cannot be determined. Another characteristic of the spines is that they are

slightly inclined toward the ventral side of the shell. Unlike the highly irregular apertures of most non-spinose platyceratids, their apertures are circular to elliptical without obvious sinuses or folds which are usually interpreted as adaptation to the coprophagous life style on the crinoid tegmen. The platyceratids with tubular spines reached their largest shell size during Middle Devonian in the species P. (P.) dumosum Conrad. The length of its shell can be greater than 10 cm (3.3 inches). More strikingly, specimens with spines longer than 8 cm (2.5 inches) have been reported, and there can be more than 100 spines on one shell (Keyes, 1890; Meek, 1873). It would appear to have been next to impossible for these gigantic gastropods to live on the tegmen of the crinoids.P. (P.) dumosum have not been reported attached to a crinoid tegmen. During the Late Devonian, the shell size of these gastropods became much smaller, represented by P. (P.) echinodum. The irregular pattern of the spines, however, did not change until the Mississippian. Despite the fact that a large number of in situ specimens of the platyceratid-crinoid associations have been found, very few if any spinose platyceratids are among them. There are only two reported cases where spinose platyceratids are associated with crinoids. One is from Hinde (1890) who reported a spinose platyceratid attached on the tegmen of a crinoid from the Middle Devonian of Ontario, Canada, and tentatively called it a variety of P. (P.) dumosum (the updated name is P. (P.) echinodum). However, no illustration or descriptions were provided. The second case is from Kesling and Chilman

139 1 cm

Figure 6.2 Mississippian platyceratid with regular patterns of spines on the shell.

140 (1975). They illustrated a specimen from the Silica Formation of the Middle Devonian of Ohio with two platyceratid individuals attached to a single individual of Arthroacantha carpenteri. Interestingly enough, the snail on the crinoid tegmen is P. bucculentum, which is a species with no spines, whereas the snail attached to the side of the same calyx is P. rarispinum, which is a species with spines. Rollins and Brezinski (1988) have reinterpreted the crinoid-piatyceratid interaction based on Mississippian specimens from southern Pennsylvania, and they stated, at least for the Mississippian specimens, that the relationship was clearly detrimental to the crinoid host and that coprophagy may be just one of the feeding strategies available to the platyceratids. Baumilller (1990) did a study on the drilling abilities on the Mississippian pla^ceratids. He serially sectioned a crinoid specin en {Macrocrinus mundulus) with Playteras (Orthonychia) on its tegmen and found a borehole just beneath the snail. He interpreted this as another feeding strategy of the platyceratids that is different from the generally-held coprophagous life style in which the snail sits directly over the crinoid anus. In his review of this relationship, Boucot (1990) considered the coprophagous life-style to probably not be obligate for all platyceratids and only those taxa actually found in situ on a host crinoid may be safely considered to have been coprophagous. Taking into account the history of the spinose platyceratids and the characteristics of the current collection, this group of platyceratid gastropods, especially those from the Mississippian, probably did not live on the crinoid tegmens. The function of their long, tubular spines may have been used as supporting apparatus on a muddy substratum, as protective ornament, or both. More conclusive interpretations can only be made if specimens in their living position can be found in future work.

6.5. SYSTEMATIC PALEONTOLOGY

141 Phylum MoUusca Class Gastropoda Cuvier, 1797 Order Archaeogastropoda Thiele, 1925 Suborder Trochina Cox and Knight, 1960 Superfamily Platyceratacea Hall, 1859 Family Platyceratidae Hall, 1879 Genus Platyceras Comad, 1840 Type species. - Pileopsis vetusta Sowerby, 1829, by subsequent designation, Tate, 1869. Subgenus Platyceras Phillips, 1841 Platyceras (Platyceras) tribulosum 1883

Platyceras tribulosum White, 1883, p. 186, pi. xli, figs. 6a-b. Capulus tribulosus Keyes, 1890a, p. 9. Capulus tribulosus Keyes, 1894, p. 175, pi. liii, figs. lla-c. Description.-Shé)l small, subspiral, rather slender, one early whorl coiled, expanding regularly into uncoiled mature part of the shell, aperture circular to elliptical, sometimes with an indistinct sinus; growth lines fine, numerous and distinctive all over the shell surface; also marked by three diagnostic longitudinal rows of long, tubular spines, extending from the apertmal margin to approximately the end of the first volution; the spines become larger adapically; two rows of spines disposed laterally, one on each side, and the third centrally and dorsally, spines in the lateral rows somewhat inclined toward the ventral side; the maximum number of spines in each row 5 to 6. Remarks.- This is one of the only two platyceratid species in the Mississippian of North America with tubular spines on them. Compared with the non-spinose platyceratids preserved in the same bed, this species is conspicuously smaller in size and less abundant.

142 Morphological variation with this species is also much more limited than within non- spinose species. OccMrrence.-Burlington Limestone, Hannibal and Louisiana, Missouri; Nada member of Borden Formation, Morehead, Kentucky. Material.-6 specimens are available for study.

Platyceras (Platyceras) biserialis Hall, 1859 Platyceras biserialis Hall, 1859, p. 90. Platyceras biserialis Meek and Worthen, 1868, p. 509, pi. xv, figs. 3a-b. Capulus biserialis Keyes, 1890a, p. 9; 1890b, p. 167. Capulus biserialis Keyes, 1894, p. 177, pi. liii, figs. 12a-b. Remark.-T)n& general morphology of this species is very similar toPlatyceras (Platyceras) tribulosum Hall except that it has only two longitudianl rows of tubular spines on each side of the shell. Shell slender and small sized; aperture circular or elliptical; growth lines numerous and fine over entire shell; two longitudinal spines on each side of the shell; spines inclined toward the ventral side. O ccurrence.limestone, Quincy, Illinois; Nada Member of Borden Formation, Morehead, Kentucky. Material.-S specimens are available for study.

Platyceras (Platycjras) equilaterialis Hall, 1860 /^emnrL-Morphological variations within this species is enormous as documented by Yochelson (1969), Lane and Yochelson (1973). The current specimens are well within the morphological range of the species definition. On the other hand, the current collection has many fewer representatives that developed distinctive sinuses on the apertural margin. The current species is very rarely preserved attached to the tegmen of a crinoid. Only one

143 specimen was found that has Agaricocrinus as the host, but the snail is badly crushed and could be either P. (P.) equilaterialis Hall or P. (P.) acutirostre (Hall). Occurrence.- Keokuk Limestone, Wayland, Missouri; Keokuk and Bonaporte, Iowa; Warsaw and Niola, Illinois; Burlington Limestone, Burlington, Iowa; Springfield, Missouri; Edwards ville Formation of Borden Group, Crawfords ville and Monroe Reservoir, Indiana; Nada Member of Borden Formation, Morehead, Kentucky. MateriaL-6 specimens are availble for study. Subgenus Orthonychia Hall, 1843 Type Species—Platyceras {Orthonychia) subrectum Hall, 1859. Platyceras (Orthonychia) acutirostre (Hall) 1856 Remark.-Thc current specimens match the species description updated by

Yochelson (1969), Lane and Yochelson (1973). Unlike Lane and Yochelson's (1973) collection from Crawfordsville, Indiana, this species far oumumbered P. (P.) equilaterialis Hall in the current study area. Most specimens are straight cones with or without apertural sinuses. Specimens with partially coiled apex are very rare. Many specimens have acrothoricid barnacle borings on the shell surface. Occurrence.- Keokuk limestone, Wayland, Missouri; Keokuk and Bonaporte, Iowa; Warsaw and Niola, Illinois; Burlington limestone, Burlington, Iowa; Springfield, Missouri; Edwardsville formation of Borden Group, Crawfordsville and Monroe Reservoir, Indiana; Nada member of Borden Formation, Morehead, Kentucky. Materials.-Mot& than 24 specimens are available for study.

144 CHAPTER?

CONCLUSIONS

The deltaic nature of the Borden Formation was well established by previous authors. The Nada Member of the Borden Formation in eastern Kentucky is interpreted as the Borden delta platform deposits. The Edwardsville Formation of the Borden Group in southern Indiana is environmentally equivalent to the Nada Member, but was younger in age than the Nada as a result of the westward progradation of the Borden delta. Therefore, it provides a good opportunity to examine the temporal changes in the Borden delta platform communities. Two sedimentary facies were recognized in the Nada. The interdistributary mudstone facies is predominantly greenish, gray mudstones, shales, with some minor siltstones. This facies represents a quiet, muddy, soft substratum. Numerous fossils such as crinoids, rugose corals and brachiopods are preserved in this facies, again, indicating a low energy environment. The carbonate tempestite facies was represented mostly by carbonate lenses and stringers. Under thin-section study, these carbonates were not pure. They contained various amounts of terrestrial ingredients. A combined classification scheme of Folk (1962), Dunham (1962), Zuffa (1980) and Mount (1985) was developed to accommodate the mixed nature of this facies. Based on rield observations and thin-section studies, this facies was interpreted as storm deposits below the fair weather wave base. The

145 fauna that was associated with this facies was considered autochthonous or parautochthonous. Glauconites and phosphatic nodules existed throughout the Nada. Many well- preserved fossils, such as conulariids, brachiopods, cephalopods, have been found inside the phosphatic nodules. Microscopically, all glauconite grains were apparently fecal pellets, which are the most common origin of glauconite grains. The abundant presence of

glauconites and phosphates probably indicates the Nada represents a period of transgression and the abandonment of the Borden delta in eastern Kentucky. A new type of biotic-interaction was found in the Nada. It was a Cladochonus colony that encrusted a platyceratid gastropod Platyceras acutirostre that was probably still sitting on a crinoid tegmen when they were alive. As a result of the tabulate coral’s encrustation, the size of the platyceratid gastropod was much smaller compared with the average size of the species, indicating that the encrustation was detrimental to the growth of the gastropod. The tabulate coral colony benefited from this relation by the elevation that the gastropod and the crinoid provided. The crinoid fauna in the Nada has 25 species within 18 genera and 12 families. Four major crinoid groups existed in the Nada, and they were camerates, disparids, cladids and flexibles. Monobathrid camerates are the predominant group represented by the species Uperocrinus pyriformis, which is the most abundant crinoid species in the Nada. One new genus iPlscocrinus) and four new species {Uperocrinus acuminatus, Aorocrinus nodulus, Discocrinus protuberatus, and Ateiestocrinus kentuckyensis) have been established in this study. Platyceratid gastropods are one the most abundant fossil groups in the Nada. Although the majority of platyceratid gastropods do not provide accurate biostratigraphic information, the two species that possess spines qualify for index fossils for the middle Osagean time of North America. The two species arePlatyceras biserialis and Platyceras

146 tribulosum. Contrary to the general belief that all platyceratid gastropods lived a coprophagous life on the tegmen of crinoids, these platyceratids with tubular spines probably did not associate with cinoids and lived a firee life on the sea floor. The Nada Member of the Borden Formation in eastern Kentuclqr and Edwardsville Formation in southern Indiana were both interpreted as the Borden delta platform deposits. Detailed paleocommunity research has been carried out by Ausich et al. (1979) and Ausich (1983). The Nada mudstone community was approximately 3.5 millions years older than the Edwardsville mudstone community. This time difference fits well into the 2 to 6 million years of stasis (EE Subunit) of the coordinated stasis model proposed by Brett and Baird. In this research project, four aspects of the community structures of the Nada and Edwardsville have been carefully examined and compared. They were taxonomic composition, trophic groupings, guild structure and component distribution. It turns out that the two communities were vastly different in terms of the four factors mentioned above. If we follow the coordinated stasis model, we should expect to see similarities rather than differences. However, the actual data showed the sharp differences between the two communities. There is a possibility that a boundary between two EE subunits occurred between the Nada and the Edwardsville. Nevertheless, there is no evidence indicating large scale environmental perturbations between the Nada and the Edwardsville. The conclusion is that the coordinated stasis model does not apply to the Borden delta platform communities.

147 APPENDIX A

SYSTEMATICS OF NON-CRINOID FAUNA (Synomyay lists are truncated)

Phylum Brachiopoda Dumeril, 1806 Class Inarticulata Huxley, 1869 Order Lingulainda Waagen, 1885 Superfamily Lingulacea Menke, 1828 Family Lingulaidae Menke, 1828 Genus Lingula Bruguiere, 1797 Lingula sp. Remarks.- One specimen preserved inside a nodule, displaying fine, concentric growth lines and possibly original shell coloration. Another specimen is preserved on the surface of a glauconitic carbonate. Both are partially exposed, and not well enough preserved to identify species. Occurrence.- M146 section, Nada Member of the Borden Formation, Morehead, Kentucky.

Class Articulata Huxley, 1869 Order Spriferida Waagen, 1883 Superfamily Athyridacea M'Coy, 1844

148 Family Athyrididae M'Coy, 1844 Genus Actinoconchus M'Coy, 1844 Actinoconchus lamellosus (Leveille, 1835) Athyris lamellosa Leveille, 1835. Weller, 1914, p. 456-467, pl. 78, fîgs. 1-5; 15-20. Athyris lamellsoa Leveille, 1835. Boucot, Johnson and Stanton, 1965, p. 662, fig. 375:4b-d.

Athyris lamellosa Leveille, 1835. Ausich, 1978, p. 208. Actinoconchus lamellosus (Leveille,1835). Brunton, 1980, Bull. Br. Mus. Nat. HisL (Geol.) 34(4):225-227, figs. 16-17. Actinoconchus lamellosus (Leveille, 1835). Lewis, 1986, pp. 146-149, pl. 10, figs. 1A-4E. Descnpr/on.-Biconvex shell if preserved intact, wider than long with rounded cardinal shoulders; hinge line short; anterior commissure weakly to moderately uniplicate; lamellose flanges well-developed in some individuals; radial striae and spines absent. Pedicle valve most convex posteriorly, weakly to moderately inflated; beak small; interarea almost absent, foramen relatively large at the very end of the beak; sulcus very weakly developed posteriorly, becoming moderately to well developed anteriorly. Brachial valve slightly convex; beak small; fold weakly developed or totally lacking posteriorly, becoming moderately elevated anteriorly. Internal structures not available. Remarks.- This fossil was placed in Athyris lamellosus. Brunton (1980) first placed it into Actinoconchus for reasons of the special shell surface structure. The difference between Athyris and Actinoconchus is is that the latter had greatly extended fiills "forming a flat, circular, striated disc". An additional difference is that Athyris has a more conspicuously developed sulcus and fold. Brunton emphasized that Athyris remains typical

149 during the Devonian than the Carboniferous, and it contains species lacking the long, lamellose shell extensions that are typical ofActinoconchus and Cleiothyridina. A unique taphonomical character of this species is that it is commonly found "being flattened out" into thin sheets. This phenomenon could indicate that this species had a unique shell structure that made it mineralogically more susceptible to "crushing" during compaction, that it was a strongly biconvex shell with thin valves, and that it commonly occurs in mudstones that have undergone considerable compaction. Moreria/.-MK-69, many completely preserved individuals, most of them crushed. Occurrence.- This species is cosmopolitan in all Lower Mississippian rocks of North America.

Order Spriferida Waagen, 1883 Superfamily Spiriferacea King, 1846 Family Spiriferidae King, 1846 Genus Spirifer Sowerby, 1816 Spirifer rowleyi^eX\&t, 1914 Spirifer rowleyi Weller, 1914, p. 360-361, pi. 53, figs. 3-6; pi. 54, figs. 1-4. Spirifer cf. rowleyi Weller, 1914. Macqueen and Bamber, 1967, p. 32, pi. 1, fig. 7.

Description.- Shell large in size; transversely subelliptical in outline; subequally biconvex; hinge line a little shorter than the maximum width; cardinal extremities subangular or rounded; costae relatively wide, broadly rounded, 25-30 on each lateral slope, bifurcating; 14-20 costae per sinus or fold; minute radiating striae usually conspicuous. Pedicle valve with greatest convexity near the mid-length or slightly posterior, umbonal region relatively narrow; interarea moderately arched, vertically grooved;

150 deltherium rather large, about twice as wide at base as high; sulcus extending from beak to anterior margin, ill-defrned laterally. Brachial valve with maximum convexity near the umbonal region; interarea low; fold well-defined from beak to anterior margin. Internal parts unknown. Remarks.- This species is easily recognized by its large size, its narrow umbonal region, and its well-developed sinus and fold. A closely allied species is Spirifer grimesi, which differs by its wider umbonal region and the absence of conspicuous minute striae. The specimens from the Nada Member are mostly fragmented and incomplete. Usually only one valve is preserved. There is one small specimen in the current collection that is much below the average size for the species and it is deemed to be a juvenile individual. The number of costae in the sulcus and fold in the Nada collection are a little fewer than the previously described specimens of this species. Materials.- MK-73,74,75,76, 77. One specimen is complete, an the remainder are imcoplete with only one valve preserved. Occurrence.- Fern Glen Formation and Burlington Limestone of Missouri; Banff Formation of both the Northwestern Territories and Alberta, Canada; Nada Member of the Borden Formation, Morehead, Kentucky.

Spirifer latior Sv/ailow, 1863 Spirifer /ar/or,Swallow, 1863. Weller, 1914, p. 316-317, pi. 38, figs. 9-13. Spirifer latior S^NalXov/, 1863. Banson, 1944, pi. 36, figs. 38-40.

Remarks.- The current specimens frt into all the previous descriptions and illustrations well by its small size, rotund form, and poorly-defined sulcus and fold. Materials.- Many cast and mold specimens.

151 Occurrence.-Chouteau Limestone, Missouri; Nada Member of the Borden Formation, Morehead, Kentucky.

Order Strophomenida Ôpik, 1934

Superfamily Prodictiacea Gray, 1840 Family Buxtoniidae Muir-Wood and Cooper, 1960 Subfamily Buxtoniidae Muir-Wood and Cooper, 1960 Genus M arginatia Muir-Wood and Cooper, 1960 Marginatia burlingtonensis (Hall, 1858) Productus flemingi var. burlingtonensis Hail, 1858, p. 598, pi. 12, figs. 3a-g. Productus burlintonensis (Hall, 1858). Weller, 1914, pp. 104-105, pi. 9, figs. I-IO. Marginatia burlingtonensis (Hall, 1858). Carter, 1987, pp.39-40, pl.9, figs. 1-8. Description.-She]l of medium size, hinge-line about equalling the greatest width of the body of the shell, pedicle valves geniculated; shell surface marked by rounded, radiating costae and transverse rugose, prominently reticulate posteriorly; spines sparse, mostly at the anterior portion of the pedicle valve, very rare on brachial valve. Pedicale valve strongly convex, umbonal region protruding beyond the hinge-line; sulcus originating in the umbonal region and going all the way to the posterior margin, not very well defined. Brachial valve gently concave in its posterior region; reticulate ornamentation all over the shell surface; no distinctive spines; cardinal process trilobe with a small medial lobe; adductor scars dendritic; lateral ridges prominent, ending at the cardinal extremities; low, thin median septum reaching farther than the middle of the valve; brachial ridges branch obliquely. Remarks.-T\us is a common productid species from the Burlington Limestone and its equivalents. A very similar species is Marginatia femglenensis (Weller), which has a

152 lower curvature to its pedicle valve, and absence or slight development o f the sulcus of the pedicle valve. Carter (1987) designated Af. burlintonensis as a zonal fossil species for the Banff Formation of western Alberta and correlated it with early Osagean Burlington Limestone in the Upper Mississippi Valley Region. Materials.- MK-78, 79, 80, 81. OccM/rence.-Burlington Limestone, Burlington, Iowa; Banff Formation, western Alberta, Canada; Nada Member of the Borden Formation, Morehead, Kentucky.

Family Leioproductidae Muir-Wood and Cooper, 1960 Genus Spinocarinifera Roberts, 1971 Subgenus Seminucella Carter, 1987 Spinocarinifera (Seminucella) sp. Remarks.- Nada specimens fit the definition of Spinocarinifer (Seminucell) well with its small size, semioval outline, sparse spines and geniculated pedicle valve. It differs fromAvonia by having a less elongate outline and a more geniculated brachial valve. Nevertheless, the species-level designation is difRcult because of the absence of any internal structures. When Roberts (1971) first established the genus Spinocarinifera, it was placed in the Family Overtoniidae Muir-Wood and Cooper, 1960. Carter (1987) reassigned this genus into family Leioproductidae probably because of the presence of a alveolus at the cardinal process. Materials.-M¥i.-\.3i. Occurrence.- Banff Formation (upper Kinderhookian to middle Osagean), western Alberta, Canada; Nada Member rf the Borden Formation, Morehead, Kentucky.

Family Overtoniidae Muir-Wood and Cooper, 1960

153 Subfamily Overtoniinae Muir-Wood and Cooper, I960 Genus Rhytiophora Muir-Wood and Cooper, I960 Rhytiophora arcuatm (Hsdl, 1858) Productus arcuatus Hall, 1858. Weller, I9I4, p. 107, pi. I3,figs. I-I2. Rhytiophora? arcuatus (Hall, 1858). Rodriguez and Gutschick, 1967, p. 372-374, pi. 42, figs. 11-14, 16-19, 26. Remarks.- The current specimens fit into the species definition well. Materials.- MK-146, many molds and casts; no brachial valves preserved. Occurrence.- Chouteau Limestone, Missouri; Nada Member of Borden Formation in Morehead, Kentucky; Banff Formation, Alberta, Canada; Kazakh SSR, Russia.

Family Echinoconchidae Stehli, 1954 Subfamily Echinoconchinae Stehli, 1954 Genus Ec/iinoconc/iMJ Weller, 1914 Echinoconchus sp. Remarks.-One incomplete specimen with well-preserved concentric bands bearing spines, diagnostic ofEchinoconchus. Occurrence.- Nada Member of Borden Formation, Morehead, Kentucky.

Family Producddae Gray, 1840 Genus Productus Sowerby, 1814 Productus sedaliensis Weller, 1914 ? ? Productus sedaliensis Weller, 1914, p. 108, PI. 14, figs. 1-7. Remarks.- One specimen with well-preserved costae and concentric growth lines is allied with P. sedaliensis. Because of the incompleteness of the specimen, the specific designadon is not certain.

154 Occurrence.- Fem Glen Limestone, Illinois; Nada Member of Borden Formation, Morehead, Kentucky.

Suborder Chonetidina Muir-Wood, 1955 Superfamily Chonetacea Bronn, 1862 Family Chonetidae Bronn, 1862 Subfamily Rugosochonetinae Muir-Wood and Cooper, 1962 Genus Rugosochonetes Sokolskaya, 1950 Rugosochonetes multicosta Winchell, 1863 Chonetes multicosta Winchell, 1863. Weller, 1914, p. 79-80, PI. 8, figs. 8-16. Chonetes (Rugosochonetes) multicostus (Winchell, 1863). Fotieva, 1961, p. 104, PI. 9,

figs. 11-12.

Diagnosis.- Small size, fine costae, hinge line equal to maximum shell width. Descritpion.- Shell small, concavo-convex; the greatest width typically at the hinge- line; cardinal extremities nearly rectangular. Pedicle valve convex, the greatest convexity posterior to the middle, compressed toward the cardinal extremities; umbo very small; deltherium broadly triangular, much wider than high, the inner surface of the valve finely papillose beyond the middle; surface marked throughout by very fine, regular radiating capillae. Brachial valve unknown. Remarks.- This species is closely allied with another Burlington Limestone species R. illinoisensis Worthen. However, the latter has the greatest width somewhere below the hinge-line; smaller, more rounded cardinal extremity; and coarser surface ornamentation. Materials.- MK-138 (two individual specimens of the pedicle valves).

155 Occurrence.- Burlington Limestone, Fem Glen Limestone, Iowa, Missouri; Saskatchewan, Canada; Touraasian, Timan, Russia; Nada Member of the Borden Formation, Morehead, Kentucky.

Phylum Conulariida Babcock and Feldmann, 1986 Genus Paraconularia Sinclair, 1940 Paraconularia subulata(HaU, 1858) Paraconularia subulata Babcock and Feldmann, 1986, p. 435-441, figs. 3.3, 3.5-3.6, 21.4, 29.1-29.10, 30.1-30-8, 31.1-31.5, 33.4. Remarks.-AtXl specimens from the current collection are preserved in nodules. One specimen (MK-147) is almost completely preserved with well-defined rods and clear rod articulation. They fit well into previous descriptions and illustrations of the species. Materials.— MK-147, MK-153. Occurrences.- Lower Mississippian of Illinois, Indiana, Kentucky, Montana, Ohio.

Genus Conularia Miller in Sowerby, 1821 Conularia multiccstata Meek and Worthen, 1865 Conularia multicostata Babcock and Feldmann, 1986, p. 385-391, figs. 9.1-9.5, 9.8, 10.1, 10.4, 12.1-12.5. Remarks.-The current specimen is assigned to C. multicosta because of its very closely spaced rods and its inflected gothic arch rod articulation. One incomplete specimen has well-preserved rods. Materials.— MK-163. Occurrence.-Lower Mississippian of Indiana, Kentucky and Ohio.

Phylum Arthropoda Siebold and Stannius, 1845

156 Class Trilobita Walch, 1771 Order P^chopariida Swinnerton, 1915 Superfamily Proetacea Salter, 1864 Family Proetidae Salter, 1864 Genus Paladin Weller, 1936 Paladin chesterensis (Weller, 1936)

Paladin chesterensis Brezinski, 1988, p. 940, figs. 2.28; 2.29; 2.31; 2.32; 2.34. Remarks.— Several pygidia are in the current collection. They fit well into the previous descriptions and illustrations. This species was originally described fi*om Upper Mississippian rocks of the Appalachian basin. It turns out that it is also a rather common species in Osagean rocks. It is also known fi-om the Kinderhookian (Brezinski, 1988). Materials.— Only pygidia were found. Preservation is variable with one individual well preserved. MK-186, 188. Occurrences.—Mauch Chunk Formation of Peimsylvania; Cuyahoga Formation, Logan Formation, and Max ville Limestone of Ohio; Nada Member of the Borden Formation, Morehead, Kentucky.

Family Brachymetopidae Prantl and Pribyl, 1950 Genus Australosutura Amos, Campbell and Goldring, 1960 Australosutura lodiensis (Meek, 1875) Australosutura lodiensis (Meek, 1875). Brezinski, 1988, p. 936, figs. 2.13; 2.14; 2.19; 2.20; 2.22-2.24. Brachymetopus rusticus Hyde, 1953, p. 344, p. 53, fig. 1-6.

157 Remarks.—On& individual pygidium with well-preserved longitudinal rows of pustules on the axial parts and the pleural parts. Nada material fits into all the previous descriptions and illustrations of A. lodiensis. Materials.— , 188 (the cast of MK-187). Occurrences.— Cuyahoga Formation and Logan Formation of Ohio; Nada Member of the Borden Formation, Morehead, Kentucky.

Class Cephalopoda Cuvier, 1797 Subclass Nautiloidea Agassiz, 1847 Order Orthocerida Kuhn, 1940 Superfamily Orthocerataceae M'Coy, 1844 Family Orthoceratidae M'Coy, 1844 Genus Michelinoceras Foerste, 1932 Michelinoceras sp. Remarks.- One incomplete specimen preserved in a nodule, with subcylindrical orthocones, siphuncle central or eccentric. Occurrences.— Nada Member of the Borden Formation, Morehead, Kentucky.

Order Nautilida Agassiz, 1847 Superfamily Tainocerataceae Hyatt, 1883 Family Koninckioceratidae Hyatt in Zittel, 19(X) Genus Subvestinautilus Turner, 1954 Subvestinautilus sp. Remarks.— Four incomplete specimens are in the current collection. The biggest individual has a diameter of proximately 30 cm and has well-preserved suture lines. All characteristics, except the unusually large size, fit into Subvestinautilus.

158 A/arcrfa/j.—Four specimens, MK-194,195, 196, 198 Occurrences.— Nada Member of the Borden Formation, Morehead, Kentucky.

Class Bival via Linne, 1681 Subclass Anomalodesmata Dali, 1889 Order Pholoadomida Newell, 1965 Superfamily Pholadomyacea Gray, 1847 Family Granunysiidae Miller, 1877 Genus Sanguinolites M'Coy, 1844 Sanguinolites websterensis Weller, 1899 Sanguinolites websterensis Weller, 1899. Hyde, 1953, p. 311-312, p. 39, fig. 1, pi. 43, figs. 11-14. Remarks.- The current specimen fits well into S. websterensis by its large shell size, elongate form, clear escutcheon and fine concentric ornamentation. Material.- Two specimens are available. Occurrences.- Logan Formation, Sciotoville, Ohio; Vermicular Sandstone, Webster County, Missouri; Nada Member of the Borden Formation, Morehead, Kentucky.

Class Anthozoa Ehenberg, 1834 Subclass Tabulata Milne-Edwards and Haime, 1850 Family Auloporidae Milne-Edwards & Haime, 1951 Genus Cladochonus M'Coy, 1847 Cladochonus beecheri (Grabau, 1899) Cladochonus beecheri (Grabau, 1899). Lane, 1973, p. 95, p. 7, figs. 1-11.

159 Remarks.- Most of the colonies start as an initial leptant ring around a crinoid stem (except in one case where they attached on Platyceras acutirostre), and then branch out C beecheri differs from C. crassus by its much more robust and longer individual coralla. Materials.— MK-174. Occurrence.- Lower Mississippian, cosmopolitan.

Cladochonus crassusl Remarks.- Similar preservations as in C beecheri, but many fewer examples. Materials.— MK-162. Occurrence.- Lower Mississippian, cosmopolitan.

160 APPENDIX B

lit h o l c x j Ic a l t h in s e c t io n descriptions

The beginning number in each description is the name of the specific section. MI46 represents Mile Post 146 Section. M149 represents Mile Post 149 Section. FE represents Frenchburg East Section. FW represents Fcenchburg West Section. HC represents Hill Top Church Section. 460E represents Hwy460 Section. For the locations of the different sections, refer to Fig. 1.2.

M146NI-1 Glauconitic, allochemic siltstone Skeletal Composition (-30%): brachiopods, echinoderms, bryzoans, corals, pelecypods; most skeletals are much larger than 2 mm, rarely complete; partially dissolved skeletals rare; infiltration fabrics in some big shell fragments, indicating an alternating high and low water energy condition; Matrix/Cements (-70%): angular, quartz silts making most of the matrix, cemented by interstitial calcites, which seem to be microspars. Noncarbonate Intrabasin Minerals (<5%): glauconite pelloidal grains occasionally in the matrix, with sharp clear boundaries, indicating original formation. Comments: calcite cements have two possible origins, l)inorganic precipitation in a shelf, shallow sea, 2)early diagenetic (penecomtemporaneous) dissolution of the calcite skeletal materials. Various portions of the section have various ratios of

161 calcite versus quartz silt, probably resulting from the irregular distribution of the skeletals.

FE2-fl Allochemic clayey siltstone Skeletal Composition (-10%): echinoderms, bryozoans, often with irregular margins as a result of diagenetic calcite dissolution. Matrix/Cements (80-90%): fine silts with clayey cements and minor amount of microspars; Noncarbonate Intrabasin minerals: none Comments: most of the skeletals are somewhat dissolved with irregular margins, and the dissolved calcite filling the voids adjacent to the skeletals; in some portions of the section, the amount of clays increases drastically, forming a mudstone layer.

FWb-4 Biosparite Skeletal Composition (>80%): bryozoans, echinoderms, brachiopods, corals, pelecypods, ostracods(?); all skeletal materials are a little micritized, and compacted together, thus, clear boundaries rarely occur between grains. Matrix/Cement (10-20%): microspars and minor fine silts. Noncarbonate Intrabasin Minerals: none Comments: Calcite skeletons almost make up the entire fabric, indicating a local restricted environment where the terrigenous siliciclastic materials were absent or winnowing of fine-grained siliciclastic.

FE6-t Glauconitic and phosphatic silty biosparite Skeletal Composition (>80%): bryozoans. echinoderms, brachiopods, allochems not

162 compacted together, bryozoans are the dominant skeletons, along with very large echinoderm fragments. Matrix/Cement (-10%): fine silts to clays with very minor microspars. Noncarbonate Intrabasin Minerals (-10%): some glauconite (8%) and some phosphate. Comments: very similar to FWb-4, except for the minor amount of glauconite and phosphate, indicating the same depositional environment.

FE4-t Allochemic mudstone Skeletal Compostion (-10%): brachiopods, echinoderms, usually in large pieces. Matrix/Cement (-80%): fine silts and clay minerals (some micas?), with elongate morphology and orientation. Noncarbonate Intrabasinal Minerals: none Comments: the entire rock fabric is dominated by clay or fine silt material with large pieces of skeletons, indicating a quiet depositional environment where organisms died and were buried in the original living environment.

FE3-t Phosphatic silty biomicrite Skeletal Composition (-40%): bryozoan, echinoderms, brachiopods, many of the skeletons are highly micritized and partially dissolved. Matrix/Cement (-40%): fine quartz silt and clay filling the voids between the skeletons.

Noncarbonate Intrabasinal Minerals (10-20%): phosphate grains and minor glauconites, phosphate grains are about sand-sized, with clear margins. Comment: The large amount of phosphatic material possibly indicates a rich biological source. It can also be a result of depositional hiatus.

163 M146tl Phosphatic allochemic siltstones Skeletal Composition (~30%): bryozoans, brachiopods, echinoderms, coral, many skeletons are partially dissolved, the size of the skeletons are extremely varied. Matrix/Cement (-60%): fine quartz silt (40%) cemented by calcite microspar (20%), silt size is very uniform. Noncarbonate Intrabasin Minerals: abundant phosphate grains (<10%), usually filling the voids between the skeletons, especially inside the bryozoa zooecia. Comments: the abundance of the phosphates indicates a rich biological source, the calcite microspar is probably produced by the dissolution of the skeletons.

M146t2 Phosphatic allochemic siltstones Skeletal Composition (

HC9t Micritic dolomite Skeletal Composition: none. Matrix/Cements: dolomitic micrites made up the entire fabric. Noncarbonate Intrabasin Minerals: none. Comments: no skeletal materials are in this facies. Possible burrows are the only indication

164 of biotic activity.

M149t3 Glauconitic silty packstone Skeletal Composition (-60%): bryozoans, echinoderms, brachiopods, corals. Matrix/Cement (-20%) : mostly fine silt to clay with very minor microspar cement. Noncarbonate Intrabasinal Minerals: abundant glauconite grains (-20%) with typical pelloidal morphology, usually filling various voids inside the skeletons and between the skeletons. Comments: glauconite grains are a major part of the entire fabric, distributed among all the void, but still having clear boundarires, typical pellet-related glauconite grains.

HC5-C Burrowed silty micritic dolomite with stromatolitic structures Skeletal Compostion: none. Matrix/Cement: dolomitic micrites with some silts in the more silty interbeds of the algal structures. Comment: interbedded muddy and silty layer with branching burrows only in the muddy layers; within the micritic laminations typical blue and green algae structures are easily recognized with their typical pelleting texture; combined with the field observations of typical algal structures, this seems to represent a very shallow water (supertidal?) or even tidal flat depositional enviroimaent where blue-green algal growth intertwined with the silty or muddy sedimentation.

460E1 clayey intraclastic biosparite Skeletal Compostition (-50%): bryozoans, echinoderms, brachiopods, most skeletons are aligned and compacted into linear morphologies.

165 Matrix/Cement: many intraclasts (-20%) present along with the skeletal materials, most of them elliptically shaped; clay (-10%) and calcite microspar (-20%) are the major cements. Noncarbonate Intrabasin Minerals: minor amount of glauconite. Comment: This is a unique microfacies. The entire fabric is very similar to foliated metamorphic rocks, with all the allochems (skeletals and intralclasts) aligned unidirectionally and somewhat crushed; for most of the skeletal material it is hard to determine the original morphology; much of the micropar is probably due to the dissolution of the skeletal materials.

HCl Itl Biomicrite

Skeletal Composition (-30%): Bryozoans, brachiopods, many of them are hard to recognize; most of the skeletal material is micritized to various degrees. Matrix/Cement: (-70%): micrite material makes up the entire matrix. Noncarbonate Intrabasinal Minerals: none. Comment: This sample was from the St. Louis Limestone that is above the Renfro Member. It indicates a qui et normal marine shelf environment.

M149tl Silty Allochemic Biosparite Skeletal Composition (-80%): echinoderms (>60%), bryozoans, brachiopods, with the echinoderms in very large pieces. Matrix/Cement: minor fine silt (-5%) and calcite spar that is obviously from the syntaxial growth of the skeletal materials (-15%). Noncarbonate Intrabasin Minerals: minor amount of glauconites. Comment: cementation of this type of rock is obviously penecontemparary when the skeletal framework still had voids unfilled by the siliciclastic material. The

166 source of the syntaxial calcite could be either the dissolution of the original skeletal materials or the calcite existing in the diagenetic fluids.

M149t2 Glauconitic silty biosparite Skeletal Composition (-80%): echinoderms, bryzoans, brachiopods. Matrix/Cement (~10%j): fine silts and clays. Noncarbonate Intrabasinal Minerals (-10%): abundant glauconite grains filling many bryozoan zooecial pores and other interstitial spaces. Comment: skeletal materials constitute the bulk of this microfacies, with only miniscule amounts of silt and clay, indicating a more clear water environment with abundant living organisms.

HC7t Micritic Dolomite Skeletal Composition: none. Matrix/Cememts: dolomitic micrite making up the entire fabric. Noncarbonate Intrabasin Minerals: none. Comment: almost exactly the same as HC9t, indicating an alternating depositional environment inside the Renfro Member.

167 APPENDIX c

DESCRIPTION OF THE FOUR MEASURED NADA SECTIONS (See Figure 1.2 for the locations of the following sections)

Frenchburg East Section, East of Frenchburg, Morehead, Kentucky

St Louis Limestone Gray, thick-bedded, massive limestones with occasional chert nodule layers. Thickness: > 3.0 m Renfro Member 2. Yellowish, grayish, dolomites, mudstone-like after being weathered. Thickness: 4.0 m 1. Yellowish dolomites interbedded with siltstones and shales, boundaries are gradual. Thickness: 2.5 m Nada Member 7. Silty greenish shale, no fossils Thickness: 0.4 m 6. Purplish, reddish and greenish shales, containing many

phosphatic nodules. Thickness: 2.5 m 5. Structureless, pure greenish shales Thickness: 1.5 m 4. Grayish, greenish shales with carbonate stringers that contain abundant fossils (crinoids, brachiopods, corals,

168 bryozoans etc.). Thickness; 1.2 m 3. Greenish shales with minor carbonate lenses containing brachiopods, crinoid stems, bryozoans etc. Thickness: 1.5 m 2. Greenish shales with skeletal carbonate lenses. Thickness: 1.6 m 1. Reddish, purplish, greenish shales with mashed skeletal materials. Thickness: 2.5 m Cowbell Member Greenish siltstones intercalated with greenish shale containing phosphatic nodules at the top. Thickness: >3 m

Frenchburg West Section, West of Frenchburg, Morehead, northeastern Kentucky

Renfro Member 2. Yellowish dolomites, muddy-like when weathered Thickness: >4 m 1. Grayish, yellowish dolomites interbedded with greenish shales and siltstones Thickness: 2.5 m Nada Member 6. Silty greenish shales with sharp boundary on the top. Thickness: 0.4 m 5. Purplish, reddish and greenish shales, easily weathered with many phosphatic nodules on the top. Thickness: 3.5 m 4. Greenish shales with carbonate and siltstone lenses; carbonates abundant with fossils (crinoids, brachiopods, corals, bryozoans etc.). Thickness: 4.5 m 3. Greenish, reddish shales with minor carbonates that are made up of disarticulated and broken skeletals

169 (crinoid stems, brachiooods, corals and bryozoans); fossil fragments were also in the shales. Thickness: 2.0 m 2. Greenish shales interbedded with skeletal lenses and thin siltstone layers. Thickness: 2.8 m I. Greenish shales interbedded with siltstones; no fossils present. Thickness: 2.5 m Cowbell Member Thick-bedded greenish siltstones interbedded with greenish shales; abundant phosphatic nodules present at the top; siltstones contain considerable amount of glauconite. Thickness: >5 m

Hill Top Church Section, North of Frenchburg, Morehead, northeastern

Kentucky

St. Louis Limestone Massive, thick-bedded, grey to dark limestone interbedded with chert nodule layers. Thickness: >4 m Renfro Member 6. Gray to yellowish argillaceous dolomite. Thickness: 2.2 m 5. Yellowish dolomites gradually changing into light greenish shales at the top. Thickness: 0.9 m 4. Gray to greenish, silty mudstones with abrupt boundaries at the top and the bottom. Thickness: 0.05m 3. Grayish to yellowish dolomites, sharply bounded

170 below and above. Thickness: 0.3 m 2. Gray to yellowish shales sharply bounded below and above. Thickness: 0.04 m 1. Gray to yellowish muddy dolomite with thin laminations. Thickness: 0.8 m Nada Member 4. Greenish, grayish siltstones at the botttom and greenish shales at the top, abundant glauconites present at the top of the bed. Thickness: 0.4 m 3. greenish shales with abundant phosphatic nodules that rarelly contain conulariids, brachiopods, cephalopods, fish bones etc. Thickness: 0.7 m 2. Greenish, structureless mudstones with no fossils; boundaries below and above are gradual. Thickness: 2m 1. Dark, reddish shales containing no fossils. Thickness: 2m

Nada Section at 146 Mile Post of 1-64, Morehead, northeastern Kentucky

Renfro Member Yellowish, grayish argillaceous dolomite, protruding on outcrop due to differential weathering. Thickness: >Im Nada Member 5. Structureless, greenish, sometimes reddish, shales with abundant phosphatic nodules, no fossils in the shales although fossils were inside the nodules. Thickness: 2.9 m

171 4. Greenish shales interfoedded with siltstones and limestone lenses; abundant glauconites associated with siltstones; abundant fossils in the limestone

lenses. Thickness: 7.5 m 3. Grey, greenish shales with minor siltstone lenses, abundant in glauconites; many trace fossils present. Thickness: 3.7 m 2. Reddish, greenish, structureless shales with rare fossils. Thickness: 1.4 m 1. Greenish shales with thin carbonate lenses, abundant in fossil fragments (crinoid stems, bryozoan, brachiopods). Thickness: >2 m

172 APPENDIX D

Locality information (refer to Fig. 1.2 for locality number and location)

Locality No. Name of Locality Crinoid Specimens

1 1-64 mile post 146 MK-2, MK-5, MK-6, MK-7, MK-9, MK-11, MK-14, MK-24, MK-27, MK-29, MK-31, MK-34, MK-35, MK- 85, MK-183

2 1-64 mile post 149 MK-1, MK-4, MK-12, MK-13, MK-15, MK-16, MK-17, MK-19, MK-21, MK-23, MK-28, MK-82, MK-95, MK-139, MK-194, MK-195

3 Leatherwood MK-46, MK-94, MK-87

4 Hilltop Church MK-33

5 Frenchburg West MK-18, MK-26, MK-29, MK-32, MK-81, MK-96, MK-98, MK-169, MK-170

173 (Appendix D continued) 6 Frenchburg East MK-181

7 Highway 460 West MK-IO, MK-25, MK-30, MK-83, MK-89

8 Highway 460 East MK-20

174 BIBLIOGRAPHY

Aigner, T. 1982. Calcareous tempestites: storm-dominated stratigrafîcation of Upper Muschelkalk limestones (middle Trias, SW Germany), pp. 180-198. In Einsele, G. and A. Seilacher (eds.). Cyclic and Event Stratification, Springer-Verlag, Berlin. Arendt, Y.A. 1985. Biotic relationships of crinoids. Paleontological Journal, 19(2):67-63. Aronson, R.B., and W.F. Pecht. 1997. Stasis, biological disturbance and community structure of a Holocene coral reef. Paleobiology, 23:326-346. Ausich, W.I. 1978. Community Organization, Paleontology, and Sedimentology of Lower Mississippian Borden Delta Platform (Edwardsville Formation, Southern Indiana). Unpublished PhJD. Disseration, Indiana University. ------1980. A model for niche differentiation in Lower Mississippian crinoid communities. Journal of Paleontology, 54:273-288. ------1983a. Component concept for the study of paleoconununities with an example from the Early Carboniferous of southern Indiana. Palaeogeography, Palaeoclimatology, Palaeoecology, 44:251-282. ------1983b. Functional morphology and feeding dynamics of the Early Mississippian crinoid Barycrinus asteriscus. Joum^ of Paleontology, 57:31-41. ------1986. Palaeoecology and history of the Calceocrinidae (Paleozoic Crinoidea). Palaeontology, 29:85-99. ------1988. Evolutionary convergence and parallelism in crinoid calyx design. Journal of Paleontology, 62:906-916. ------.1998. Early phytogeny and subclass division of the crinoidea (phylum Echinodermata). Journal of Paleontology, 72:499-510. Ausich, W.I., and T.K. Baumiller. 1993. Taphonomic method for determing muscular articulations in fossil echinoderms: a test for the occurrence of muscles in Lower Mississippian cladid crinoids. Palaios, 8:477-484. Ausich, W.I., and D.J. Bottjer. 1982. Tiering in suspension feeding communities on soft substrata throughout the Phanerozoic. Science, 216:173-174. 175 Ausich, W.I., T.W. Kammer, and N.G. Lane.1979. Fossil communities of the Borden (Mississppian) delta in Indiana and northern Kentucky. Journal of Paleontology, 53:1182-1196. Ausich, W.I., and T.W. Kammer. 1991. Systematic revisions to Aorocrinus, Dorycrinus, Macrocrinus, Paradichocrinus, Strotocrinus, and Uperocrinus: Mississippian camerate crinoids (Echinodermata) from the strato^rpe region. Journal of Paleontology, 65:936-944. , ------. 1990. Systematics and phytogeny of the late Osagean and Meramecian crinoids Platycrinities and Eucladocrinus firom the Mississippian stratotype region. Journal of Pieontology, 64:759-778. -, and T.K. Baumiller. 1994. Demise of the Middle Paleozoic crinoid fauna: a single extinction event or rapid faunal turnover? Paleobiology, 20:345-461. , ------, and D i . Meyer. 1997. Middle Mississippian disparid crinoids from the midcontinental United States. Journal of Paleontology, 71:131-148. , and N.G. Lane. 1982. Crinoids from the Edwardsville Formation (Lower Mississippian) of southern Indiana. Journal of Paleontology, 56:1343-161. Ausich, W.L, and G.D. Sevastopulo. 1994. Taphonomy of Lower Carboniferous crinoids from the Hook Head Formation, Ireland. Lethaia, 27:245-256. Babcock, L.E. and R.M. Feldmann. 1986. Devonian and Mississippian conulariids of North America. Part B.Paraconularia, Reticulaconularia, new genus, and organisms rejected from Conulariida. Annals of Carnegie Museum, 55:411-479. Bambach, R.K., and J.B. Benington. 1996. Do communities evolve? A major question in evolutionary paleoecotogy. in Jablonski, D., D.H. Erwin, and J.H. Lipps (eds.). Evolutionary paleobiology, p. 123-160. Barrel!, J. 1912. Criteria for the recognition of ancient delta deposits. Bulletin of Geological Society of America, 23:377-446. Bassler, R. S., and M. W. Moodey. 1943. Bibliographic and faunal index of Paleozoic pelmatozoan echinoderms. Geological Society of America Special Paper 45,734 p. Baumiller, T.K. 1990. Non-predatory drilling of Mississippian crinoids by platyceratid gastropods. Palaeontology, 33:743-748. Baumiller, T.K. 1997. Crinoid functional morphology. Paleontological Society Papers, 3:45-68. Bjerstedt, T.W., and T.W. Kammer. 1988. Genetic stratigraphy and depositional systems of the Upper Devonian-Lower Mississippian Price-Rockwell deltaic complex in the Central Applachians, USA. Sedimentary Geology, 54:265-301. Bottjer, D.J., and W.l. Ausich. 1986. Phanerozoic development of tiering in soft 176 substrata suspension feeding communities. Paleobiology, 12:400-420. Boucot, A J. 1983. Does evolution take place in an ecological vacuum? Journal of Paleontology, 57:1-30. Boucot, AJ. 1990. Evolutionary paleobiology of behavior and coevolution. Elsevier, Amsterdam, p.20-26. Bowsher, A i. 1955. Origin and adaptation of platyceratid gastropods. University of Kansas Paleontological Contributions, Mollusca Article 5:1-11. Brett, C.E., and G.C. Baird. 1995. Coordinated stasis and evolutionary ecology of Silurian to Middle Devonian faunas in the Appalachian Basin, in E r^ n , D. and R.L. Anstey (eds.). New approaches to spéciation in the fossil record. Columbia University Press, New York, p.285-315. Brett, C.E., L.C. Ivany, and K.M. Schopf. 1996. Coordinated stasis: an overview. Palaeogeography, Palaeoclimatology, Palaeoecology, 127:1-20. Brezinski, D.K. 1988. Appalachian Carboniferous trilobites. Journal of Paleontology, 62:934-945. Bromley, R.G. 1990. Trace fossils, biology and taphonomy. Unwin Hyman, London. Brower, J.C. 1987. The relations between allometry, phytogeny and functional morphology in some calccocrinid crinoids. Journal of Paleontology, 61:999-1032. Brunton, C.H.C. 1980. Type specimens of some Upper Palaeozoic Athyridide brachiopods. Bulletin of British Museum of Natural History (Geology), 34:219-234. Burst, J.F. 1958. ‘Glauconite’ pellets; their mineral nature and application to stratigraphie interpretations. Bulletin of American Association of Petroleum Geology, 42:310-327. Carter, J.L. 1968. New genera and species of Early Mississippian brachiopods from the Burlington Limestone. Journal of Paleontology, 42:1140-1152. ------1987. Lower Carboniferous brachiopods from the Banff Formation of western Alberta. Geological Survey of Canada Bulletin 378, p. 183. ------, and R.C. Carter. 1970. Bibliography and index of North American Carboniferous brachiopods (1898-1968). Geological Society of America Memoir 128,382 p. Chaplin, J R. 1980. Stratigraphy, trace fossil associations, and depositional environments in the Borden Formation (Mississippian), northeastern Kentucky. Annual Field Conference Guidebook, Geological Society of Kentucky, 1980. Kentucky Geological Survey, 114 p.

177 Clarke, J.M. 1908. The beginnings of dependent life. New York State Museum Bulletin 121 (61st Aimud Report, V.l), p. 149-169. ------. 1909. Early Devonic history of New York and eastern North America. New York State Museum Memoir 9, part 2, p. 1-125. Cox, L.R. 1969. Biology of Bivalvia. pp. N5-N11. In Moore, R.C. (ed.). Treatise on Invertebrate Paleontology, Ft. N, Mollusca 6, Bivalvia. Geological Society of America and University o f Kansas, Lawrence. Craig, L.C., and Vames, K.L. 1978. History of the Mississippian System - An interpretative summary. U.S. Geological Survey Professional Paper, 1010:371- 406. Dodd, J R., and R.J. Stanton, Jr. 1981. Paleoecology, concepts and applications. John Wiley and Sons, Inc. New York. Dunham, R J. 1962. Classification of carbonate rocks according to depositional texiure. in W.E. Ham (ed.). Classification of carbonate rocks. Memoir of American Association of Petroleum Geology V.l. Ehlers, G.M., and R.V. Kesling. 1963. Two new crinoids from Lower Mississippian rocks in south-eastern Kentucky. Journal of Paleontology, 37:1028-1041. Einsele, G., and A. Seilacher. 1991. Distinction of tempestites and turbidites. pp. 377- 382. In Einsele, G., W. Ricken and A. Seilacher (eds.). Cycles and Events in Stratigraphy. Springer, Berlin. Eldredge, N. and S.J. Gould. 1972. Punctuated equilibria: an alternative to phyletic gradualism, pp. 82-115. In Schopf, T.J.M. (ed.). Models in Paleobiology. Freeman, San Francisco. Elliott, T. 1986. Deltas, in H.G. Reading (ed.). Sedimentary environments and facies, p. 113-154. Blackwell Scientific Publications, Oxford, Boston. Folk, R.L. 1962. Special subdivision of limestone types, in W.E. Ham (ed.). Classification of carbonate rocks. Memoir of American Association of Petroleum Geology, 1:62 84. Fotieva, N.N. 1961. Toumasian chonetids of Timan-Pechora Province. Paleont. Zhumal, no.4, p.100-108. Frazier, W.J., and D R. Schwimmer. 1987. Regional stratigraphy of North America. Plenum Press, New York and London. Funish, W.M., and B.F. Glenister. 1964. Paleoecology of cephalopoda, in Moore, R.C. (ed.). Treatise on invertebrate pdeontology. Part K, Mollusca 3. p.Kl 14-K125. Gilbert, G.K. 1890. Lake Bonnevile. U.S. Geological Survey, Monograph 1, 438p.

178 Hall, J. 1858. Report on the Geological Survey of Iowa, embracing the results of investigations made during portions of the years 1855, 1856,1857. Geological Survey of Iowa, vol.l, part 2, paleontology, 724p. . 1859. Geology of Iowa, Supplement to Volume 1, p.90. . 1860. Contributions to the paleontology of Iowa: being descriptions of new species of Crinoidea and other fossils. Iowa Geological Survey, supplement to volume 1, pt. 2 of Geology Department of Iowa, 94 p. . 1861a. Descriptions of new species of Crinoidea from the Carboniferous rocks of the Mississippi Valley. Boston Society of Natural History Journal, 7:261-328. . 1861b. Descriptions of new species of Crinoidea and other fossils, from the Carboniferous rocks of the Mississippi Valley. Iowa Geological Survey Report of Investigations, Preliminary Notice, p. 1-19. . 1879. Geological Survey of the State of New York, Paleontology, 5:1-21. Hall, J., and R.P. Whitfield. 1875. Descriptions of Crinoidea from the Waverly Group. Geological Survey of Ohio, Volume 2. Geology and Paleontology, part 2. Paleontology, p. 162-179. Harland, W.B., R.L. Armstrong, A.V. Cox, L.E. Craig, A.G. Smith, and D.G. Smith. 1990. A geological time scale 1989. Cambridge University Press. Cambridge. Hill, D. 1981. Paleoecology. pp. F47-F49. In Teichert, C. (ed.). Treatise on Invertebrate Paleontolo^, Pt. F, Coelenterata, Supplement 1, Rugosa and Tabulata, vol. 1. Geological Society of America and University of Kansas, Lawrence. Hill, D., and L.B. Smyth. 1938. On the identity of M onilopora Nicholson and Etheridge, 1879, with Cladochonus M cCoy, 1847. Royal Irish Academy ProceeiSngs, Series B, 45:125-138. Hinde, G.J. 1885. Description of a new species of crinoids with articulating spines. The Annuals and Magzine of Natural History, Series 5, 15:157-173. Hoffman, A. 1979. Community paleoecology as an epiphenomenal science. Paleobiology, 5:357-379. Hyde, J.E. 1953. Mississippian formations of central and southern Ohio. Ohio Division of Geological Survey Bulletin 51. Jablonski, D., D.H. Erwin, and J.J. Lipps (eds.). 1996. Evolutionary paleobiology. University of Chicago Press, Chicago. Johnson, H.D., and C.T. Baldwi*;. 1986. Shallow siliciclastic seas in Reading, H.G. (ed.). Sedimentary environments and facies. Blackwell Scientific Publications. Oxford, London.

179 Kammer, T.W. 1984. Crinoids from the New Providence Shale Member of the Borden Formation (Mississippian) in Kentucky and Indiana. Journal of Paleontology, 58:115-130. Kammer, T.W. 1985a. Basinal and prodeltaic communities of the Early Carboniferous Borden Formation in northern Kentucky and southern Indiana (U.S.A.). Palaeogeography, Palaeoclimatology, Palaeoecology, 49:79-121. Kammer, T.W. 1985b. Aerosol filtration theory applied to Mississippian deltaic crinoids. Journal of Paleontology, 59:551-560. Kammer, T.W. and W.I. Ausich. 1987. Aerosol suspension feeding and current velocities: distributional controls for late Osagean crinoids. Paleobiology, 13:379-395. Kammer, T.W. and W.I. Ausich. 1996. Primitive cladid crinoids from Upper Osagean- Lov/er Meramecian (Mississippian) rocks of east-central United States. Journal of Paleontology, 70:835-866. Kammer, T.W., T.K. Baumiller, and W.I. Ausich. 1998. Evolutionary sigmficance of differential species longevity in Osagean-Meramecian (Mississippian) crinoid clades. Paleobiology, 24:155-176. Kammer, T.W. and T.W. BjerstedL 1986. Stratigraphie framework of the Price Formation (Upper Devonian-Lower Mississippian) in West Virginia. Southeastern Geology, 27:13-33. Kaufman, E.G. and R.W. Scott. 1976. Basic concepts of community ecology and paleoecology. In: Scott, R.W. and R.R. West (eds). Structure and classification of paleoconununities. Bowden, Hutchinson and Ross, Stroudsburg, PA. pp. 1-28. Kennedy, W.J., and R E. Garrison. 1975a. Morphology and genesis of nodular phosphates in the Cenomanian glauconitic marl of south-east England, Lethaia, 8:339-360. ------1975b. Morphology and genesis of nodular chalks and hardgrounds in the upper Cretaceous of southern England, Sedimentology, 22:311-386. Kepferle, R.C. 1977. Stratigraphy, petrology, and depositional environment of the Kenwood Siltstone Member, Borden Formation (Mississippian), Kentucky and Indiana. U.S. Geological Survey Professional Paper 1007, 49p. Kesling, R.V., and R.B. Chilman. 1975. Strata and megafossils of the Middle Devonian Silica Formation. Museum of Paleontology, University of Michigan, Papers on Paleontology, No. 8. Keyes, C.R. 1890a. General relations ofPlatyceras and Capulus. American Geologist, 6:6-9.

180 Kammer, T.W. 1984. Crinoids from the New Providence Shale Member of the Borden Formation (Mississippian) in Kentucky and Indiana. Journal of Paleontology, 58:115-130. Kammer, T.W. 1985a. Basinal and prodeltaic communities of the Early Carboniferous Borden Formation in northern Kentucky and southern Indiana (U.S.A.). Palaeogeography, Palaeoclimatology, Palaeoecology, 49:79-121. Kammer, T.W. 1985b. Aerosol filtration theory applied to Mississippian deltaic crinoids. Journal of Paleontology, 59:551-560. Kammer, T.W. and W.I. Ausich. 1987. Aerosol suspension feeding and current velocities: distributional controls for late Osagean crinoids. Paleobiology, 13:379-395. Kammer, T.W. and W.I. Ausich. 1996. Primitive cladid crinoids from Upper Osagean- Lov/er Meramecian (Mississippian) rocks of east-central United States. Journal of Paleontology, 70:835-866. Kammer, T.W., T.K. Baumiller, and W.I. Ausich. 1998. Evolutionary significance of differential species longevity in Osagean-Meramecian (Mississippian) crinoid clades. Paleobiology, 24:155-176. Kammer, T.W. and T.W. Bjerstedt. 1986. Stratigraphie framework of the Price Formation (Upper Devonian-Lower Mississippian) in West Virginia. Southeastern Geology, 27:13-33. Kaufman, E.G. and R.W. Scott. 1976. Basic concepts of community ecology and paleoecology. In: Scott, R.W. and R.R. West (eds). Structure and classification of paleoconununities. Dowden, Hutchinson and Ross, Stroudsburg, PA. pp. 1-28. Kennedy, W.J., and R E. Garrison. 1975a. Morphology and genesis of nodular phosphates in the Cenomanian glauconitic marl of south-east England, Lethaia, 8:339-360. ------1975b. Morphology and genesis of nodular chalks and hardgrounds in the upper Cretaceous of southern England, Sedimentology, 22:311-386. Kepferle, R.C. 1977. Stratigraphy, petrology, and depositional environment of the Kenwood Siltstone Member, Borden Formation (Mississippian), Kentucky and Indiana. U.S. Geological Survey Professional Paper 1007, 49p. Kesling, R.V., and R.B. Chilman. 1975. Strata and megafossils of the Middle Devonian Silica Formation. Museum of Paleontology, University of Michigan, Papers on Paleontology, No. 8. Keyes, C.R. 1890a. General relations ofPlatyceras and Capulus. American Geologist, 6:6-9.

180 ------, 1890b. Synopsis of American Carbonic Caiyptraeidae. Academy of Natural Sciences, Philadelphia, Proceedings, p.150-181. ------. 1892. The Platyceras group of Palaeozoic gastropods. American Geologist, 10:273-277. ------_ 1894. Paleontology of Missouri, Part. 1. Missouri Geological Survey, 4:143-225. Kidwell, S.M., and D.W.J. Bosence. 1991. Taphonomy and time-averaging of marine shelly faunas. In Allison, P.A. and D.E.G. Briggs (eds.), Taphonomy: Releasing the Data Locked in the Fossil Record. Plenum Press, New York. Kirk, E. 1945. Holcocrinus, a new inadunate crinoid genus from the Lower Mississippian. American Journal of Science, 234(9):517-521. Kluessendorf, J. 1983. Observations on the commnsalism of Silurian platyceratid gastropods and stalked echinoderms. Transactions of the Wisconsin Academy of Sciences, Arts and Letters, 71:48-55. Knight, J.B., L.R. Cox, M.A. Keen, R.L. Batten, E.L. Yochelson, and R. Robertston. 1960. Systematic descriptions. In Moore, R.C. (ed.). Treatise on invertebrate paleontology. Part I. Mollusca, 1169-1310. Geological Society of America and University of Kansas Press, Lawrence, Kansas. 35 Ip. Kreisa, R.D. 1981. Storm-generated sedimentary structures in subtidal marine facies with examples 6om the Middle and Upper Ordovician of south-western Virginia. Journal of Sedimentary Petrology, 51:823-848. LaBarbera, M. 1984. Feeding currents and particle capture mechanisms in suspension feeding animals. American Zoologist, 24:71-84. Lane, N.G. 1958. The Monobathrid Camerate Crinoid Family: Batocrinidae. Unpublished Ph.D. dissertaion. University of Kansas, Lawrence, 259 p. . 1963. Two new Mississippian camerate (Batocrinidae) crinoid genera. Journal of Paleontology, 37:691-702. . 1973. Paleontology and paleoecology of the Crawfordsville fossil site (Upper Osagean: Indiana). University of California Publications in the Geological Sciences, 99, 14Ip. . 1978. Paleontology and paleoecology of the Crawfordsville fossil site (Upper Osagean: Indiana). University of California Publications in Geological Sciences, V.99. University of California Press. 1983. Progradation of the Borden delta: new evidence from crinoids. Journal of Paleontology, 57:112-123. Lane, N.G., and J R. DuBar. 1983. Progradation of the Borden delta: New evidence from crinoids. Journal of Paleontology, 57:112-123. 181 Laudon, L. R. 1948. Osage-Meramec contact. Journal of Geology, 56:288- 302. . 1973. Stratigraphie crinoid zonation in Iowa Mississippian rocks. Proceedings of the Iowa Academy of Sciences, 80(l):25-33. and J. L. Severson. 1953. New crinoid fauna, Mississippian Lodgepole Formation, Montana. Journal of Paleontology, 27:505-536. Lewis, R.R. 1986. Brahiopods of the Nancy Member of the Borden Formation (Mississippian), northeastern Kentucky. Unpublished MS thesis. Wright State University. Lineback, J.A. 1969. Illinois basin-sediment-starved during Mississippian. American Association of Petroleum Geologists Bulletin, 53(1):112-126. Lucas, J., and L.E. Prevot. 1991. Phosphates and fossil preservation, in Allison, P.A. and D.E.G. Briggs (eds.), Taphonomy: releasing the data locked in the fossil record. Plenum Press, New York and London. Mason, C.E., and J R. Chaplin. 1979. Nancy and Cowbell Member of the Borden Formation in Ettensohn, F.R. and G.R. Dever, Jr. (eds.). Carboniferous Geology from the Appalachian Basin to the Illinois Basin through Eastern Ohio and Kentucky: Field Trip No. 4, Ninth International Congress of Carboniferous Stratigraphy and Geology: Lexington, University of Kentucky. Matchen, D.L., and T.W. Kammer. 1994. Sequence stratigraphy of the Lower Mississippian Price and Borden Formation in southern West Virginia and eastern Kentucky. Southeastern Geology, 34:25-41. Meek, F.B. 1873. Description of invertebrate fossils of the Silurian and Devonian Systems. Report of the Geological Survey of Ohio, Geology and Paleontology, 1:210-213. Meek, F.B., and A.H. Worthen. 1868. Geological Survey of Illinois, 3:509. . 1869. Descriptions of new Carboniferous fossils from the western states. Academy of Natural Sciences of Philadephia, Proceedings, 22:137-172. . 1873. Paleontology. Description of invertebrates from Carboniferous system. Illinois Geological Survery, 5(2):323-619. Messing, C.G., M.C. RoseSmyth, S.R. Mailer, and J.E. Miller. 1988. Relocation movement in a stalked crinoid (Echinodermata). Bulletin of Marine Science, 42:480-487. Meyer, D.L. 1982. Food and feeding mechanisms: Crinozoa. in Jangoux, M. and J.M. Lawrence (eds.). Echinoderm Nutrition. A.A. Balkema, Rotterdam. p.25-42. Meyer, D.L. 1985. Evolutionary implications of predation on Recent comatulid crinoids from the Great Barrier Reef. Paleobiology 11:154-164.

1 8 2 Meyer, DX. and W. I. Ausich. 1983. Biotic interactions among Recent and fossil crinoids. In Tevesz, MJ.S. and McCall, PX. (eds.). Biotic interactions in Recent and fossil benthic communities, p.378-427 Meyer, D. L., and W. I. Ausich. 1997. Morphological variation within and among populations of the cameratecnnoid Agaricocrinus (Lower Mississippian, Kentucky and Tennessee): Breaking the spell of the mushroom. Journal of Pdeontology, 71(5):896-917. Meyer, D.L., W.I. Ausich, and R.E. Terry. 1989. Comparative taphonomy of echinoderms in carbonate facies: Fort Payne Formation (Lower Mississippian) of Kentucky and Tennessee. Palaios, 4:533-552. Miller, A.I. 1997. Coordinated stasis or coincident relative stability. Paleobiology, 23:155-164. Moore, R.C. 1962. Revision of Calceocrinidae in Echinodermata. Article 4, The University of Kansas Paleontological Contributions, p. 1-40. The University of Kansas Publication. Moore, R. C., and L. R. Laudon. 1943. Evolution and classification of Paleozoic crinoids. Geological Society of America Special Paper 46,153 p. . 1944. Crinoidea, p. 137-211. In, H. W. Shimer and R. R. Sbrock, Index Fossils of North America. J. Wiley and Sons, Inc., N.Y. Morris, P.J., L.C. Ivany, K.M. Schopf, and C.E. Brett. 1995. The challenge of paleoecological stasis: reassessing sources of evolutionary stability. Proceedings of National Academy of Science, USA, 92:11269-11273. Mount, J.F. 1984. Mixing of siliciclastic and carbonate sediments in shallow shelf environments. Geology, 12:432-435. Mount, J.F. 1985. Mixed siliciclastic and carbonate sediments: a proposed first-order textural and compositional classification. Sedimentolgy, 32:435-442. Muir-Wood, H.M., and G.A. Cooper. 1960. Life and habits of the Productoidea. Geological Society of America Memoir 81. Owen, D. D., and B. F. Shumard. 1850. Descriptions of fifteen new species of Crinoidea from the Subcarboniferous limestone of Iowa. Acad. Nat. Sci. Philadelphia, Jour., ser.2, 2:57-70. . 1852. Decriptions of one new genus and twenty two new species of Crinoidea from the Subcarboniferous limestone of Iowa, p. 587-598. In, D. D. Owen, Report of a Geological Survey of Wisconsin, Iowa, and Minnesota. Patzkowsky, M E., and S.M. Holland. 1997. Pattern of turnover in Middle and Upper Ordovician brahiopods of the eastern United States: a test of coordinated stasis. Paleobiology, 23:420-443. Pemberton, F.G, J.A. MacEachem and R.W. Frey. 1992. Trace fossil facies models: 183 environmental and allostratigraphic significance, pp. 47-72. In Walker, R.G. and N.P. James (eds.): Facies Models, Response to Sea Level Change. Geological Association of Canada. Riddle, S.W. 1989. Functional morphology and paleoecological implications of the platycrinitid column (Echinodermata, Crinoidea). Journal of Paleontology, 63:889-897. Riddle, S.W., J.I. Wulff, and W.I. Ausich. 1988. Biomechanics and stereomic microstructure of Gilbertsocrinus tuberosus column, in Burke, R.D. et al. (eds.). Echinoderm biology. Proceedings of 6th International Echinoderm Conference, Victoria, Balkema, Rotterdam, p.641-648. Roades, D.C. 1975. The paleoecological and environmental significance of trace fossils. In Frey, R.W. (ed.). The study of trace fossils. Springer-Verlag, New York, p. 147-160. Roberts, J. 1971. Devonian and Carboniferous brachiopods from the Bonaparte Gulf Basin, northwestern Australia; Bureau of Mineral Resources, Geology and Geophysics Bulletin 122, 319 p. Rodriguez, J. and R.C. Gutschick. 1967. Brachiopods from the Sappinton Formation (Devonian-Mississippian) of western Montana. Jounai of Paleontology, 41:364-384. Rollins, H.B. and D.K. Brezinsky. 1988. Re-interpretation of crinoid-platyceratid interaction. Lethaia, 21:207-217. Roeser, E.W. 1986. A Lower Mississippian (Kinderhookian - Osagaen) crinoid fauna fi'om the Cuyahoga Formation of northeastern Ohio. Unpublished MS thesis. University of Cincinnati. Rowley, R.R. 1901. Two new genera and some new species of fossils from the Upper Paleozoic rocks of Missouri. American Geologist, 27:343-355. Rudwick, M.J.S. 1965. Ecology and paleoecology. pp. H199-H214. In Moore, R.C. (ed.). Treatise on invertebrate Paleontology. Pt. H. Brachiopoda. vol. 1. Geological Society of America and University of Kansas Press, Lawrence. Sable, E.G. and G.R. Dever, Jr. 1990. Mississippian rocks in Kentucky. U.S. Geological Survey Professional Paper 1503, 125 p. Schopf, T.J.M. 1969. Paleoecology of ectoprocts. Journal of Paleontology, 43:234-244. Scott, R.W. 1978. Approaches to trophic analysis of paleocommunities. Lethaia, 11:1-14. Scott, R.W. and R.R. West (eds.). 1976. Structure and classification of paleocommunities. Dowden, Hutchinson and Ross, Stroudsburg.

184 Seilacher, A. 1967. Bathymetry of trace fossils. Marine Geology, 5:413-428. Springer, F. 1926. American Silurian Crinoids: Smithson. Inst.. Pub. 2871, p. 1-239, pi. 1-33. Stanton, R J., Jr. and J R. Dodd. 1997. Lack of stasis in late Cenozoic marine faunas and conununities, central California. Lethaia, 30:239-256. Stockdale, P.B. 1939. Lower Mississippian rocks of the east-central interior. Geological Society of America Special Paper 22,248p. Swann, D.H., J.A. Lineback and E. Frund. 1965. The Borden Siltstone (Mississippian) delta in southwestern Illinois. Illinois Geological Survey, Circular 386, 20 p. Thayer, C.W. 1986. Are brachiopods better than bivalves? Mechanisms of turbidity tolerance and their interaction with feeding in articulates. Paleobiology, 12:161-174. Teichert, C. 1964. Cephalopoda-General features; Endoceratoidea- Actinoceratoidea-Nautiloidea-Bactritoidea, in Moore, R.C. (ed.). Treatise on invertebrate paleontology. Part K, MoUusca 3. Ulrich, E. 0 . 1886. Remarks upon the names Cheirocrinus and Calceocrinus, with descriptions of three new generic terms and one new species. Minnesota Geol. & Nat. History Surfey, Ann. Rpt. 14, p. 104-113, text-ifg. 1-3. Van Sant, J. F. and N.G. Lane. 1964. Crawfords ville Indiana) crinoid studies. The University of Kansa Paleontological Contributions, Article 7, p. 136. University of Kansas. Wachsmith, C. and F. Springer. 1897. The North American Crinoidae Camerata. Museum of Comparative Zoology, Memoirs 20,21, 897 p. ------1880. Revision of the Palaeocrinoidea. Academy of Natural Sciences, Philadelphia, Proceedings, 1879. Wagner, R.H., and C.F.W. Prins. 1993. General overview of Carboniferous stratigraphy. Annales de la Société de Belgique, 116-1993, p. 163-174.

Webster, G. D. 1973. Bibliography and index of Paleozoic crinoids, 1942-1968. Geological Society of America Memoir 137. Webster, G. D. and N. Gary Lane. 1987. Crinoids from the Anchor Limestone (Lower Mississippian) of the Monte Cristo Group, southern Nevada. Paleontological Contributions of the University of Kansas, Paper 119. Weller, S. 1909. Kinderhookian faunal studies. V. The fauna of the Fern Glen Formation. Geological Society of America Bulletin, 20:265-332. — . 1914. The Mississippian Brachiopoda of the Mississippi Valley Basin. Illinois State Geological Survey Monograph 1, 508p.

185 Williams, A. et al. 1965. Brachiopoda. In Moore, R.C. (éd.). Treatise on Invertebrate Paleontology, Part H, 927p. White, C. A. 1863. Observations on the summit structure of Pentremites, the structure and arrangement of certain parts of crinoids, and descriptions of new species from the Carboniferous rocks of Burlington, Iowa. Boston Society Natural History Journal, 7:481-506. 1883. United States Geological Survey of Territories, 12th Annual Report, p. 168. Worthen, A. H. and F.B. Meek, 1875. Palaeontology of Illinois: in Geology and palaeontology, Illinois Geological Survey, vol.6, part 2, 532p. Wulff, JJ. 1991. Paleoecology ar.d paleoenvironmental analysis of the Upper Greenbrier Group (Upper Mississippian): West Virginia and western Maryland. Unpublished PhJ). Dissertation. The Ohio State University, Columbus, Ohio. Young, G.C., and J R. Laurie (eds.). 1996. An Australian Phanerozoic time scale. Oxford University Press. Yochelson, E.L. 1969. Revision of some of Girty’s invertebrate fossils from the Fayetteville Shale (Mississippian) of Arkansas and Oklahoma. Gastropods. United States Geological Survey Professional Paper, 606-0:25-33. Yochelson, E.L., and J.T. Dutro Jr. 1960. Late Paleozoic Gastropoda from northern Alaska. United States Geological Survey Professional Paper 334-0:111-147. Zuffa, G.G. 1980. Hybrid arenites: their composition and classification. Journal of Sedimentary Petrology, 50:21-29.

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