June 4, 2003
Dr. Gary Stringer, Professor in the Department of Geosciences at the University of Louisiana at Monroe, and other scientists (in two separate scientific studies) have discovered eight new fossil fishes and a new fossil ray from the area around Copenhagen, La. The fossils are from a geologic era known as the Eocene-about 36.5 million years ago.
Although the Copenhagen area southeast of Columbia in Caldwell Parish, La., has been known for its marine fossils for over 170 years, new discoveries continue to be made there by paleontologists.
Stringer and Dr. Henri Cappetta of the Institute of Science and Evolution at the University of Montpellier in France recently described the new type of genus of fossil ray (similar to sting rays in the modern Gulf of Mexico) in the prestigious European scientific journal Tertiary Research. The newly discovered fossil ray was named Eoplinthicus yazooensis by Cappetta and Stringer. The new fossil ray was based on two teeth discovered by Stringer in the Yazoo Clay (a 36.5 million-year-old geologic formation and the basis of the scientific name). The discovery is considered highly significant since it provides important information on the evolutionary development of the rays. Eoplinthicus is considered an intermediary form and helps explain the relationship between fossil rays from the Eocene and later forms.
Cappetta is the author of the Handbook of Paleoichthyology volume on fossil sharks and rays as well as over 60 other articles, chapters, and books on the topic. He is considered one of the foremost experts in the world on fossil sharks and rays.
In addition to the new fossil ray, a separate study by ULM's Stringer and Dr. Dirk Nolf of the Royal Institute of Natural Sciences in Brussels, Belgium, has been published by the Louisiana Geological Survey. In it, the two paleontologists describe eight new species of fossil fishes based on the earstones or otoliths from the same area in Copenhagen. The species represent forms that were previously unknown to the science of paleontology.
Nolf is the curator of fossil fishes at the Belgian National Museum and is regarded as the leading authority on fossil fish earstones or otoliths in the world. He has written over 100 scientific publications on fossil fishes based on otoliths including books, chapters in books, and articles. He and Stringer have collaborated on several other research projects including a major study of fossil otoliths from the Caribbean (the Dominican Republic) and a chapter in a book on fossil fish that lived during the Cretaceous Period (the time of the dinosaurs).
Stringer and Nolf discovered the new fish otoliths while studying over 5,000 fish remains from Copenhagen. The study required years of field collecting and subsequent laboratory analysis. The new discoveries by Stinger and Nolf brings the total number of fossil fish described from Copenhagen to 43 different species or types. This makes the Copenhagen locality the most prolific fossil site of this age based on otoliths known in the United States.
The fossil fish otoliths provide invaluable information on the various types of fishes that inhabited this region over 36 million ears ago as well as important data on the evolutionary development of the bony fishes. The newly discovered fossil fishes include forms similar to modern sea basses, flatfish, flounders, cusk-eels, gobies, and conger eels. By comparing the fossil fish to modern fish from the Gulf of Mexico, Nolf and Stringer were able to determine the ancient environment of Copenhagen over 36 million years ago. The fossil fish indicated that the area was covered by ocean waters with normal salinity and probably less than 50 meters in depth. The fossil fish also indicated that the bottom was soft and consisted of clay and mud and that the climate was tropical to subtropical.
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