Two principal goals motivated us to write this book. First, knowledge of the Earth’s ancient history from geology provides a powerful lesson about the ever-changing nature of the planet, and the ancient history of one’s home region can be particularly meaningful. The present nature of the landscape in the Cincinnati region (southwestern Ohio, northern Kentucky, and southeastern Indiana) is the product of its most recent geologic history, the Pleistocene Ice Age, when continental ice sheets repeatedly forced their way as far south as the Ohio River. As recently as 20,000 years ago, much of southwestern Ohio was covered with an ice sheet much as Greenland is today. As the glaciers receded, melt waters carved the present valleys and left a mantle of debris that determined the topography, drainage, soils, and vegetation of the region. A magnificent Ice Age exhibit at the Cincinnati Museum Center enhances public awareness of the profound environmental changes that took place across the region in the short time span in which humans inhabited the ice-free land. Three works also provide a concise history of the environmental changes during the Ice Age: Richard H. Durrell’s A Recycled Landscape (1977), Richard Arnold Davis’s “Land Fit for a Queen: The Geology of Cincinnati” (1981), and the recently published Natural History of the Cincinnati Region, by Stanley Hedeen (2006).
As impressive as the Ice Age history of the region is as evidence of geologic and climatic change, the story that can be told from the ancient bedrock underlying the Pleistocene cover extends the record of global change into deep time. The bedrock exposed at the surface across southwestern Ohio, northern Kentucky, and southeastern Indiana is the record of the Ordovician sea of some 450,000,000 years ago, one of the most extensive marine flooding intervals of the North American continent during Earth history. In stark contrast to the barren ice sheet of the Pleistocene, the Cincinnati seascape of the Ordovician was water from horizon to horizon—not a deep ocean blue, but perhaps shades of aquamarine like the waters over the present-day shallow Great Bahama Bank. No landmasses broke the horizon, and no birds crossed the skies. All the action was beneath the sea surface, where life thrived in abundance. This profusion of life left a fossil record in the rocks that formed from the bottom sediments of the Cincinnatian sea that is among the world’s richest treasure troves of the past. For present-day Cincinnatians, fossils in their backyards are a commonplace, and many natives grow up not realizing that most of the rest of the world has nothing to rival the fossil riches of their home! We seek to recount the history of the Cincinnati region in deep time, its vastly different environment and marine life, for the general public and for amateur geologists.
Many local residents who have been fascinated by the fossils underfoot collected and studied them almost since the earliest settlements of the eighteenth and nineteenth centuries. Generations of geologists and paleontologists from abroad have visited the region and written of the abundant fossils and the strata, including the pioneering British geologist Charles Lyell in 1842. Because the Cincinnati region has been a focus for geological research by so many scientists over so many years, there exists today a vast amount of information about the fossils and rocks of the region. This information is scattered in many sources, including the latest issues of some of the world’s leading international geological journals, Internet websites, and numerous types of publications, some widely available, some obscure. Much of the early work describing new species of Cincinnati fossils dates to the second half of the nineteenth century, and is found in periodicals no longer published, such as the Cincinnati Quarterly Journal of Science, The Paleontologist, and the Journal of the Cincinnati Society of Natural History. No single library houses all of the geological information published about the Cincinnati region. Moreover, most studies deal with only a small fraction of the total fossil richness of the region, and, most importantly for us, there has never been a synthesis of the vast range of fossil diversity and its geological context. In this book we present a synthesis that will reconstruct the life of the Ordovician sea in order to show not only what organisms inhabited this sea but also how they lived and interacted with each other to constitute the variety of ecosystems of the Ordovician sea in the Cincinnati region. The book is not intended as a textbook of geology or paleontology, but we present sufficient background information on each fossil group and the geological context for readers unfamiliar with fossils and geology. We explain what kind of animal each fossil represents and how it lived and interacted with other organisms, thereby defining the role of each group of animals in its ancient ecosystem. We hope that this approach will benefit readers with a background in geology as well as those seeking an introduction to the fossils and rocks of the Cincinnati region.
Conventions
In scientific publications, certain conventions are used to save time and trouble. These are understood by the scientists who generally write and read such publications. Because this is a scientific work, we have used some of these conventions. However, this book is also intended for the general reader who might not be familiar with such conventions. Here are some explanations:
Footnotes or endnotes are not ordinarily used in scientific publications. Instead, literature citations are inserted in the text. This commonly is done where it is appropriate in the context. At other times, especially in instances in which the reader is being referred to a number of publications, the literature citation may be at the end of the appropriate sentence or paragraph. Those enamored of footnotes or endnotes might find this peculiar, but the idea is for the reader to be referred to other publications immediately, and not have to search at the bottom of the page or the end of the chapter, or, even, volume, for the pertinent reference.
Thus, when we refer you to a publication, the literature citation will be in the following format: “(S. A. Miller 1875).” This means that you are being referred to a publication authored by S. A. Miller and published in 1875; hence, you know who said what is being cited and when. If you need the complete bibliographic information about that publication, it is provided in the bibliography toward the end of the volume. In cases in which it is important for you to know the page number within that publication where the information or quotation is found, the literature citation will be in the form “(S. A. Miller 1875, 87).”
By international agreement of zoologists, the International Code of Zoological Nomenclature is the document that specifies how the names of species, genera, and other groups of animals are stated and used in scientific works (International Commission on Zoological Nomenclature 1999). General recommendation B10 of the Code encourages that the author and date of every taxon in the species group, genus group, or family group mentioned in a publication be cited at least once in that publication, and recommendation 51G encourages the full citation of original authors and dates as well as revisers and their dates. However, such citation of authors, dates, revisers, and dates of revisions does detract from the flow of the words. Because of the intended audience of this volume, we have decided not to do such detailed citations on a routine basis, but, rather, only when clarity demands it. If you want to know the nomenclatorial history of a particular group of organisms, we recommend that you consult the scientific literature about the larger group of organisms to which those organisms belong. The bibliography of this volume is a good place to start.
We debated at some length as to whether to give a complete list of all the subdivisions for each major group of organisms discussed. We recognize that such listings might be genuinely useful for the really serious fossil-collector. However, we decided that, for the intended audience of this volume, the number of pages necessary would have made the book too long, and, hence, inordinately expensive. Up-to-date classifications can be found in the following references: the many volumes of the Treatise on Invertebrate Paleontology (a multi-authored, multi-edited series of volumes published by the Geological Society of America and the University Press of Kansas), the textbook Fossil Invertebrates (Boardman et al. 1987), or Fossils of Ohio (Feldmann and Hackathorn 1996).
Photographs, Drawings, Maps
Many of the illustrations in this volume were made specifically for this work; however, some were made by others and are used here with permission, in some instances, after modification (for example, to remove labels not pertinent to the present context). Unless otherwise indicated, a given photograph in this volume was prepared especially for this work, primarily by one of us (DLM).
Science is replete with technical terms that do not appear commonly in non-scientific contexts. To make matters worse, scientists often use common, everyday terms in ways that are not their common, everyday usages. Thus, we felt it important to include a glossary; this is found near the end of the volume. In the interests of space, however, we have not included every technical term in this book in the glossary. For its first use, each technical term is defined and is in boldface type. Those technical terms that are used in more than one chapter are listed in the glossary. A technical term that is used in only one chapter, such as the name of an anatomical feature that occurs in only one major group of organisms, is defined the first time it is used in the volume; however, we have not listed such terms in the glossary—again, in the interests of space. Such words are listed in the index to the volume.
So what do you do if you find a technical term that is unfamiliar to you and the definition is not right there where you encounter the word? First, go to the glossary. If the technical term is not in the glossary, or if, God forbid!, the coverage of that term in the glossary is insufficient, then go to the index and then to the text of the book to which you are referred. (College professors, like us, sometimes are accused of stating the obvious. Generally, this is done in an attempt to answer the questions of some students in a given class before they are asked. There is, of course, a danger of offending other students in the same class who are more adept at recognizing the obvious. And so it is with readers as well!)
In the glossary, and elsewhere, we have included advice on how to pronounce terms. As you know, lexicographers have developed a scheme of symbols to indicate how they feel particular letters, syllables, and words should be pronounced. We have tried to keep the use of such symbols to a minimum. We hope that, in so doing, we still have managed to help you pronounce words in a way useful to you.