Monday, January 6, 2020

My First Fossil is More than 330 Million Years Old

The brachiopod was discovered in riprap limestone at Wilkinson County Park in southwest Mississippi

By Roscoe Barnes III, PhD
Copyright © 2020

#Fossils
#Brachiopod

The shell imprint can be seen here just above
my thumb. The other one is below my thumb.

The rock I found near the lake at Wilkinson County Park, Woodville, in southwest Mississippi, is a fossil of a brachiopod. The rock is made of limestone and is derived from a rock formation dated approximately 335 million years old, according to Paleontology Curator George Phillips of the Mississippi Museum of Natural Science in Jackson, Miss.

I sent Mr. Phillips images of the rock via email. After reviewing the images, he said the rock is a “revetment stone,” a rock used to stabilize the banks of rivers, lakes, etc.—basically as erosion prevention. Collectively, rocks of this kind are commonly known as “riprap.” It is not naturally occurring in southwest Mississippi, which means it was brought to the area from another location. In this case, he explained, this type of stone was mined along the Tennessee Valley in northwest Alabama. He said the rock probably came from Tuscumbia Formation of that region, the name being derived from the town where Helen Keller was born.

In this image, the small shell can be
seen protruding from the rock.

While there are gravel deposits in Mississippi containing fossils of the same age, this is not a gravel fossil, according to Mr. Phillips. He said collecting fossils in gravel deposits is a popular past time in our state. Gravel fossils in Mississippi have been documented in a 2008 publication by the Mississippi Office of Geology called “Rocks And Fossils Found In Mississippi’s Gravel Deposits”—available as a free download online.

In this image, two shell imprints can be seen.

Mr. Phillips said another creature commonly found this this type of rock is the crinoid, commonly known as the “sea lily.” He explained: "Fragments of crinoid stems are a rather common and conspicuous occurrence in our gravel deposits and, because of their cylindrical shape, have often been mistaken for Native American beads.”

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ROSCOE BARNES III, Ph.D., is a writer, chaplain, historian, and former newspaper reporter. He is the author of more than a dozen books and Gospel tracts. For more information about his work and history, see his Personal Profile here or visit his website: Roscoebarnes.net. Connect with him on Twitter (@roscoebarnes3) or by email: roscoebarnes3@yahoo.com or doctorbarnes3@gmail.com

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