Upper Devonian Corals Op the Canadian Cordilleran
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UPPER DEVONIAN CORALS OP THE CANADIAN CORDILLERAN REGION by ARNOLD GORDON THOMLINSON A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in the Department of GEOLOGY AND GEOGRAPHY We accept this thesis as conforming to the standard required from candidates for the degree of MASTER OF SCIENCE Members of the Department of THE UNIVERSITY OF BRITISH COLUMBIA April, 1954 CORALS IN SLAB OF DEVONIAN LIMESTONE ACKNOWLEDGMENTS I wish to thank Dr. V.J. Okulitch, Chairman, Division of Geology, for advice on numerous paleontological problems encountered in the preparation of this thesis. To him I am also indebted for instruction and assistance in the reproduction of illustrations from the literature, and in illustration of specimens. I am especially grateful to my wife, Joan Delia Thomlinson, who has typed and patiently proof-read my manuscript. To Mrs. J.A. Donnan I also extend my thanks for the co-operative spirit with which she has undertaken typing of the thesis. Mr. J.A. Donnan, geological technician, has furthered by work by instructing me in the preparation of thin sections, and in preparing for me those which I found most difficult. My friend and fellow-student, Mr. F.A. Frebold has presented me with the beautiful specimen illustrated in the frontispiece. Both he and Mr. J.A.C. Fortescue, in discussing with me problems common to our various studies, have aided me in the development of my thesis. i ABSTRACT Preliminary to the descriptions of genera and species is a very brief discussion of coral terminology and classification. The thesis embodies descriptions and illus• trations of 29 genera and 42 species of fossil corals, reported in the literature to occur in Upper Devonian rocks of western Canada. Although most of these are reported from the Rocky Mountain area, several species from the Mackenzie River-Mackenzie Mountains area are also included. In addition, species reported from the Upper Devonian Outcrops east of the Rocky Mountains have been dealt with. Numerous taxonomic problems encountered in the study are discussed in remarks on the genera and species involved. Fossil corals collected from the region drained by the headwaters of the North Saskatchewan River are described, identified and illustrated. Nine genera and 14 species are recognized in the collection. Of these, .1 genus and 4 species do not appear to have been previously reported to occur in the Upper Devonian beds of the Rocky Mountains in Canada. The species of Coenites described is possibly a new one but it cannot be regarded as such until a study is made of literature which, at present, is not available. ii From this study of Upper Devonian corals, the writer concludes that the DISPHYLLIDAE are in need of division into new subfamilies, and he suggests two character• istics whose phylogenetic significance requires invest• igation. However, it is considered that existing paleon- tologlc data Is neither comprehensive enough nor precise enough to permit such an undertaking. Reasons are given for the present inadequacies of knowledge of Upper Devonian corals and recommendations are made for improvement of the situation. TABLE OF CONTENTS PAGE ABSTRACT i INTRODUCTION iii CHAPTER I. TAXONOMY OF FOSSIL CORALS 1 Terminology 1 Classification 4 CHAPTER II. DESCRIPTIONS OF GENERA AND SPECIES ... 8 Subclass TETRACORALLA Family HADROPHYLLIDAE Microcyclus 8 Family METRIOPHYLLIDAE Metriophyllum 10 Family ZAPHRENTIDAE Zaphrentls 12 Family BETHANYPHYLLIDAE Subfamily BET HANYP HYLLINAE Ceratophyllum 14 Family ACANTHOPHYLLIDAE Acanthophyllum 15 Cyathophyllum V$ Heliophyllum 19 Family LEPT0INOPHYLLIDAE Subfamily LEPTOINOPHYLLINAE Brevipnyllum 22 Charactophyllum 23 Diversophyllum 2b Mictophyllum 28 Subfamily GRYPOPHYLLINAE Tabulophyllum 30 Family C0LUMNARIIDAE Subfamily S P ON GOP HYLLINAE Spongophyllum 36 TABLE OF CONTENTS CONCLUDED PAGE Family DTSPHYLLIDAE Subfamily DISPHYLLINAE Aeervularia 38 Disphyllum . 39 Hexagonaria 55 Macgeea 60 Phillipsas traea 64 Subfamily ERIDOPHYLLINAE Eridophyllum 79 Family CYSTIPHYLLOIDAE Subfamily CYSTIPHYLLOINAE Cystiphylloldes . .. 80 Family C HON OP HYLLIDAE Subfamily CHONOPHYLLINAE Chonophyllum 84 Ptychophyllum 86 Subclass TABULATA Family FAVOSITEDAE Alveolites 88 Coenites 94 Favosites 99 Striatopora 103 Thamnopora 104 Family SYRINGOPORIDAE Syringopora 113 Family AULOPORIDAE Aulopora . 115 Cladochonus . 119 Romingeria 119 CONCLUSIONS 122 BIBLIOGRAPHY 124 APPENDIX A 132 APPENDIX B EXPLANATION OF PLATES 148 iii UPPER DEVONIAN CORALS OF THE CANADIAN CORDILLERAN REGION INTRODUCTION This work is intended to constitute an assem• blage of descriptions and illustrations of all fossil corals which have been reported to occur in the Upper Devonian rocks of the Cordilleran region of Canada. Possibly a more desirable goal would be the inclusion of all species reported from the Cordilleran region of North America. Unfortunately, time does not permit such a vast undertaking. The forty-ninth parallel has therefore been arbitrarily made the southern limit of this work. Although no definite northern limit has been set, the greatest emphasis has been on the Rocky Mountain area and the exposed Devonian rocks to the east. Either the Liard River or the fiftieth parallel could well serve as a northern limit for the major part of the thesis. However, a few coral species from the Mackenzie River-Mackenzie Mountains area not already covered by Smith (194-5) are included here. Because available fossil coral specimens are representative of only a small portion of the area dealt with, this work is of necessity largely a compilation from numerous published works. The literature has been searched exhaustively for fossil coral assemblages and for generic iv and specific descriptions and illustrations. Although work of this nature may lack the appeal of original study of fossil specimens, it permits, Indeed requires, the worker to become acquainted with paleontological problems and to decide upon a working solution for them. Numerous taxonomic problems involving genera and species have been encountered. Solutions I propose for such problems are, in the main, not original but are rather a result of my assessment of con• tributions of various authors. Discussion of the individual taxonomic difficulties follows the descriptions of involved genera and species. Supplemental to the literature research phase of the thesis, fossil specimens from Upper Devonian strata of the Rocky Mountains of Canada are described, identified and illustrated. Most of the fossil corals studied were collected during the summers of 1950 and 1951 by Dr. V.J. Okulitch from the area drained by the headwaters of the North Saskatchewan River. These specimens now constitute part of the paleontological research material housed at the University of British Columbia, Division of Geology. With no intention of dealing with stratigraphy I have appended, for the sake of convenience, a chart showing the major Upper Devonian stratigraphic units in which the described fossil corals are reported to occur. Also appended is a table including the genera and species reported, their localities and horizons, and an V abbreviated reference, indicating the reporter. The generic and specific names listed are those which I hold to be valid. Where my opinion is at variance with that of the writer who has reported a species, the generic and/ or specific name assigned to it by that writer is given in brackets. In each of these cases the reasons for my opinion are given in the remarks upon the genus and/or species which I recognize. 1 CHAPTER I TAXONOMY OF FOSSIL CORALS Terminology A necessary prerequisite to fossil descriptions is a set of definitions of ontogenetic and morphological terms used in the descriptions. Indeed, many coral descriptions, particularly those of the nineteenth century, lacking explan• ations of nomenclature, are meaningless, or at best ambig• uous. The condition was aggravated by lack of uniformity In use of terms by contemporary workers, and by lack of consis• tency by individual workers in their choice of terms. A trend toward standardization of terminology of tetracorals has been initiated by Hill (1935)» and carried on by Sanford (1939), Easton (1944) and Smith (1945). These workers are In accord as to the definition of most terms, and have adequately defined these terms, many of which apply equally well to the tabulate corals. More detailed discussions of tabulate coral nomenclature have been given by Swann (1947) and Ross (1953). In this work the terminology employed in describing fossil specimens has- been drawn from the works cited above, partic• ularly from Hill (1935) and Smith (1945). An exhaustive compilation here of definitions from the works referred to above would be an unnecessary 2 duplication. However, many of the generic and specific descriptions to follow, taken from the literature, contain terms which have become- ambiguous through misuse, or have fallen into disuse, or well ill-founded. It is therefore deemed necessary to provide definitionsof some of the more obscure terms met with, particularly in the older works. Furthermore, a few terms in current use, but which are not self explanatory^, are included in the hope that they will facilitate comprehension of the coral descriptions. Glossary of Terms astreiform (also astraeform) - having corallites polygonal in cross section. brephic (also nepionlc) - first ontogenetic stage in which six protosepta are developed. calycinal gemmation - mode of increase by which offsets arise from calice