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March 18, 2013

Professor Emeritus and ULM graduate collaborate on article in major paleontological volume

A newly published volume by the New Mexico Museum of Natural History and Science, “Vertebrate Coprolites,” contains an article written by Dr. Gary L. Stringer, professor emeritus of geology at the University of Louisiana at Monroe, and Lorin King (M.S. ’02), a geologist at Western Nebraska Community College. 

The article, “Late Eocene Shark Coprolites from the Yazoo Clay in northeastern Louisiana” is the culmination of years of fieldwork, collecting, and research.

According to Stringer, the volume is one of the most comprehensive and exhaustive works ever completed on the subject of fossil vertebrate coprolites. 

“Coprolites are the fossilized excrement of ancient organisms,” said Stringer. “The term actually comes from two Greek words and basically means ‘dung that has turned to stone.’” 

Stringer also commented that many paleontologists feel that the volume will become one of the most quoted references on the topic of vertebrate coprolites in the paleontological literature.

The editors noted that the volume is the first publication devoted solely to vertebrate coprolites and hope that it will provide an impetus for further study.

The publication includes articles on coprolites from all types of fossil vertebrate animals including sharks, bony fishes, amphibians, reptiles (including dinosaurs), birds, and mammals.

Stringer said since their recognition in the fossil record nearly 200 years ago, coprolites have been the topic of many discussions, both scientifically and humorously. 

“University students in historical geology classes are often amused that the excretion of animals can be preserved as fossils,” he said.

“Many people think of fossils only as hard parts of an animal such as a bone of a dinosaur or a tooth of a shark, and these certainly are fossils, which are known as body fossils.  However, fossils can also be indirect evidence of an organism.”

Stringer says that Coprolites are also classified as trace fossils, which, like a dinosaur footprint is a fossil, but not an actual part of a dinosaur like a bone, a claw, or tooth.

However, footprints can provide valuable information about dinosaurs and their behavior. 

Stringer initially became interested in coprolites as he collected samples for studying fossil fish otoliths or ear stones—his primary research emphasis.

Stringer and King conducted systematic, long-term surface collecting in a formation known as the Yazoo Clay, which is well exposed in southeastern Caldwell Parish. 

The Yazoo Clay was deposited in an ancient ocean that covered this part of the state during a time known as the late Eocene, approximately 36.5 million years ago.

Many species of sharks lived in the ancient ocean, and their presence is evidenced by fossil teeth, vertebrae, and coprolites. 

The two researchers collected almost 1,200 shark coprolites over a 30-year period.

By analyzing the distribution and occurrence of over 2,500 fossil shark teeth also obtained from the Yazoo Clay, the two were able to determine which sharks were present and most likely produced the major types of coprolites—classified as spiral and scroll.

For Stringer, one of the most amazing aspects of the study was the discovery of the remains of fish in the shark coprolites.  Stringer and King identified fish remains such as spines, vertebrae, bones, and scales in the coprolites, which provided evidence of the dietary habits of the ancient sharks. 

The authors of the 39 articles in the volume hail from universities and museums from all over the world and represent paleontologists from at least 10 countries including England, France, Canada, Denmark, Germany, Austria, Portugal, Thailand, and Brazil.

The 387 page volume is edited by Adrian P. Hunt, Jesper Milàn, Spencer G. Lucas, and Justin A. Spielmann.

It can be purchased by contacting Beth Ricker, store manager of the New Mexico Museum of Natural History and Science at

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