April 2, 2008

Oldest Prehistoric Bones Unearthed in Wisconsin Cave

Excavators in a Wisconsin cave have unearthed what may be the oldest prehistoric bones ever discovered, according to Dr. John Luczaj, an earth science professor at the University of Wisconsin-Green Bay professor.

The bones were discovered in New Hope Cave at Cherney Maribel Caves County Park in January and February.

Luczaj says they may be between 5,600 and 5,800 years old.

J.D. Skattebo, chairman and founder of the Friends of Maribel Caves, believes that there may be older bones yet to be discovered in the caves, according to data collected from excavations during the 1990s.

So far scientists have not identified what kind of animal the two vertebrae came from, but Luczaj believes they could have been from a small mammal, "bigger than a bat but smaller than a woodchuck."

Skattebo and a team of excavators discovered the bones beneath flow or float stone, which is created by calcium carbonate flowing into the cave from spring melt water.

The vertebrae were less than a centimeter in length each.

Luczaj said the cave's sediment is at least as old as the bones and probably similar in age to that in other caves in Northeastern Wisconsin. These fossils could help researchers understand what happened in the entire cave system.

"We can infer things about climate if we understand how old the deposits are and what was the environment that these organisms lived in," he said.

If weather conditions allow, excavators will resume work in May or June on a cave north of the Manitowoc.

"Our goal is to learn and understand why the caves are still there, how did they fill, and when and why," said Skattebo. "We are also studying the groundwater interaction with the water table."


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