The Bryozoan Adeonellopsis in the Paleogene of the Southeastern United “'States
Total Page：16
File Type：pdf, Size：1020Kb
Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1971 The rB yozoan Adeonellopsis in the Paleogene of the Southeastern United States. Noland Embry Fields Jr Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Fields, Noland Embry Jr, "The rB yozoan Adeonellopsis in the Paleogene of the Southeastern United States." (1971). LSU Historical Dissertations and Theses. 2122. https://digitalcommons.lsu.edu/gradschool_disstheses/2122 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. I I 72-17,760 FIELDS, Jr., Noland Embry, 1933- THE BRYOZOAN ADEONELLOPSIS IN THE PALEOGENE OF THE SOUTHEASTERN UNITED “'STATES. The Louisiana State University and Agricultural and Mechanical College, Ph.D., 1971 Paleontology University Microfilms, A XEROX Company, Ann Arbor, Michigan The Bryozoan Adeonellopsls in the Paleogene of the Southeastern United States A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Geology by Noland Embry Fields, Jr. B.A. University of Tennessee, 1955 M.S. University of Tennessee, I960 December, 1971 PLEASE NOTE: Some pages may have indistinct print. Filmed as received. University Microfilms, A Xerox Education Company ACKNOWLEDGEMENTS The author gratefully acknowledges the help received from many individuals during this study. I am especially indebted to Dr. A. H. Cheetham, Curator, Department of Paleobiology, National Museum of Natural History, the Smith sonian Institution, Washington, D.C. and Consulting Professor of Geology, Louisiana State University, for his supervision, criticism, counsel and concern. Dr. Cheetham gave freely of his time, assisted the author in field work, and made avail able study materials from the Smithsonian collections. Sincere thanks are due Dr. H. V. Andersen, Dr. W. A. van den Bold, Dr. C. 0. Durham, Dr. G. F. Hart and Dr. J. P. Morgan of Louisiana State University for manuscript review and several helpful suggestions. I also express my apprecia tion to Mr. C. J. Bangert and Mr. James Frane of the Computa tion Center, University of Kansas, for assistance concerning the NT-SYS programs and the use of computer facilities of that institution. Helpful assistance in data preparation was given by Dr. Thomas Madron of the Computer Center, Western Kentuoky University. I also extend special thanks to Mrs. Mary Ann McCelvey who typed the manuscript. I sincerely acknowledge the encouragement and support provided throughout much of this study by the late N. E. Fields, Memphis, Tennessee, the late G. E. Haught, Tuscaloosa, Alabama, and the late M. E. Byrd, Baton Rouge, Louisiana. Finally, I am most indebted to my wife, Ann, for help in innumerable small ways, preliminary typing and encouragement. TABLE OF CONTENTS PAGE ' ACKNOWLEDGEMENTS................................... ii LIST OF TABLES ..................................... vi LIST OF ILLUSTRATIONS ............................ vii ABSTRACT ............................................ ix INTRODUCTION ....................................... 1 SPECIES CONCEPTS ................................... 6 PREVIOUS STUDIES ................................... 10 PROCEDURE ......................................... 12 SAMPLING UNITS ..................................... 14 MORPHOLOGIC CHARACTERS ............................ 21 General Relationships .......................... 21 Zooecial Characteristics ........................ 27 Frontal Wall Relationships ...................... 30 Gonoecial Characteristics ...................... 39 Quantitative Characters ........................ 40 PHENETIC COMPARISON ............................... 63 PHYLOGENY AND TAXONOMY ............................ 82 General Relationships ....................... • 82 Phylogenetic Relationships ...................... 84 SUMMARY AND CONCLUSIONS .......................... 94 SYSTEMATICS ....................................... 97 BIBLIOGRAPHY ....................................... 114 V PAGE APPENDIX ............................................ 120 Regional Geology ........... .......... 121 General Lithologic Descriptions ................. 129 Sample Locations ............................ 133 Initial Data M a t r i x ............................ 143 PLATES .............................................. 147 LIST OF TABLES TABLE PAGE I Sampling Units ............................. 16 II A Zooeclal Varlates ..... .............. 43 II B Gonoecial Varlates ..... .............. 47 III Morphologic C h a r a c t e r s .................... 65 LIST OF ILLUSTRATIONS PAGE 1 Map of a Portion of the Southeastern United States and Sample Collection Area ......... 5 2 Distribution of Zoarial Fragments in Sampling U n i t s .......................................... 20 3 Generalized Adeonellopsls Zooecia.. ......... 23 4 Diagrammatical Representation of Ontogenetic Changes in Adeonellopsls ................. 35 5 Diagrammatical Representation of an Adeonellopsls Colony Fragment • . ........ 38 6 Histogram of Standard Measurements for Zooecia and Gonoecia, Sampling Unit 9 . 42 7 Histogram Summaries of Coefficient of Variation Data for Z o o e c i a .................. 53 8 Histogram Summaries of Coefficient of Variation Data for Gonoecia .................. 55 9 Scatter Polygons for Mean Zooecial D i m e n s i o n s ................................... 57 10 Scatter Polygons for Mean Gonoecial D i m e n s i o n s .............................. • 59 11 Scatter Polygons for Mean Zooecial Oral Dimensions ............................... 61 12 Dendrogram from Correlation Coefficient Matrix WPGM ................................... 71 13 Dendrogram from Correlation Coefficient Matrix UPGM ................................... 73 Dendrogram from Taxonomic Distance Matrix WPGM ................................... 75 Dendrogram from Taxonomic Distance Matrix UPGM ................................... 77 viii FIGURE PAGE 16 Dendrogram from Correlation Coefficient Matrix WPGM . ............................. 80 17 H Contour Map” of Phene tic Cl u s t e r s ........... 87 18 Inferred Phylogenetic Relationships of Adeonellopsls ................................. 90 A1 General Correlation Chart for Lithostratigraphic Units ................... 124 A2 Eocene-Oligocene Facies Relationships in Study A r e a ............................. 127 PLATE I Adeonellopsls magnlporosa..................... 149 II Adeonellopsls magnlporosa..................... 151 III Adeonellopsls transverse.... .................. 153 IV Adeonellopsls qulsenberryae.......... • • • 155 V Adeonellopsls c y c Io p b X .................. 157 VI Adeonellopsls cvolops cvclops ................ 159 VII Adeonellopsls cvclops -cvclops...................161 VIII Adeonellopsls galeata ......................... 163 IX Adeonellopsls galeata ......................... 165 ABSTRACT In many of the Eocene and Oligocene bryozoan faunules of the central Gulf Coastal Plain the adeonid genus Adeonellopsls is a frequent and distinctive member. It is one of numerous taxa which vary throughout the regional Tertiary sequence both qualitatively and quanti tatively as a result of evolutionary and ecologic influ ences. Distinctive zooecial and gonoecial structures make the species of Adeonellopsls obvious epifaunal components in the regional thanatocoenose assemblages but significant morphologic variation within and between populations as well as striking ontogenetic changes preclude a morphospe- cles approach to species determination as well as a mono- thetic classification scheme. This investigation of population characteristics and speciation in Adeonellopsls emphasizes evolutionary aspects of the species to evaluate morphology and establish taxa consistent with the biospecles concept. Inconsistencies in morphologic description and inadequate consideration of intra-colony and inter-population variation typified earlier morphospecific studies. A suite of samples from the Gulf Eocene-Oligocene outcrop belt provided specimens for the study and these were supplemented by studies of type speci mens in the National Museum of Natural History. X Approximately 150 samples were organized into 33 sampling units. A morphologic study was made on numerous individuals in each unit in order to recognize genetically controlled variation and the sources of extragenetlc varia tion in this cheilostome complex. A ‘biometric evaluation of 44 quantitative and qualitative characters inferred to be genetically based was also completed to establish the intra-colony, geographic, and stratigraphic distribution of these features. This information was summarized in code form in a data matrix for manipulation with a series of multivariate statistical procedures. Data analysis was completed by digital computer using standard techniques in numerical taxonomy to cluster related samples. Interpretation of this Information established five polythetically derived, phenetic clusters which were con sidered with their distributional data to make phylogenetic inferences and taxonomic groupings. Relationships were brought out indicating similarities