Exploring Georgia's Fossil Record & Our History of Paleontology
  • Items of Interest
    • Presentation; Oaky Woods Stratigraphy
    • I, Periarchus (A Fossil's Tale)
    • Coastal Plain Correlation Chart
    • Black & White Sketches
    • Contributing Artists
    • Public Fossil Locations >
      • South Houston County Fossils
      • Updated; Islands of the Savannah River
    • Georgia's Amateurs >
      • Amateur; Jared Dyche, On The Way To A Degree
      • Cam Muskelly, Duluth, GA
      • Kyle Keller, Valdosta, GA >
        • Kyle Keller Returns, Still Rocking!
      • Hank Josey, Dublin
      • Thomas Thurman, Warner Robins, GA
      • Bill Christy; Kamin Performance Minerals Fossils
    • Origins Of This Site
    • Georgia Fossils in the Smithsonian
  • Education Material
    • Georgia's State Fossil; Shark Teeth
    • Taking Georgia's Paleontology To Georgia's Classrooms
    • Georgiacetus Presentation; A Whale for Georgia
    • SW GA RESA 2018 Talk
    • Library & School Presentations
    • An Introduction To Fossils; Presentation
    • Georgia's Fossils Presentation; 500 million years
    • Free Fossils for GA Science Teachers; Crassostrea gigantissima
    • Georgia College Natural History Museum
  • Georgia's Lost Meteorite
  • Evolution in Georgia's Fossil Record
  • 1: Georgia's Oldest Fossils; Archaeocyathids, At 513 Million Years Old
  • 2: Trilobites; 500 Million Years Ago
    • 2A; Murray County Stromatolites
    • 2B; A Trilobite Nest in Georgia
  • 3: Geologic Time
  • 4: Our Oldest Vertebrate?
  • 5: Georgia Before the Dinosaurs
    • 5A; Georgia’s Pennsylvanian Plant Fossils
  • 6: 200 Million Years Ago
    • 6A: Birth of the Atlantic Ocean
  • 7: Cretaceous Georgia, Dinosaurs & more
    • 7A: Georgias Pterosaur
    • 7B: So Many Sharks
    • 7C: Coelecanths
    • 7D: Xiphactinus vetus
    • 7E: Side-necked turtles
    • 7F: Marine Reptiles
    • 7G: Dinosaurs in Georgia
    • 7H: Deinosuchus (Terrible Crocodile)
    • 7I; The Blufftown Formation
  • 8: Suwannee Current, Gulf Trough, & Bridgeboro Limestone
  • 9: The Clayton Formation Report; By Hank Josey
    • 9A: The Georgia Turtle
  • 10: The Eocene; Georgia's Oldest Mammals
    • 10A: The Origins of Whales
  • 11: A Whale For Georgia
  • 12: Basilosaurids; The First Modern Whales
    • 12A: Basilosaurus cetoides
    • 12B: Basilotritus
    • 12C: Cynthiacetus
    • 12D: Chrysocetus
    • 12E: The Redmond Mandible of Albany Ga
    • 12F; Houston County Basilosaurus to the Smithsonian
  • 13: Ziggy and The Museum of Arts & Sciences, Macon, GA
  • 14: Late Eocene
    • 14A: Eocene Fossils & Stratigraphy
    • 14B; Fossils, Impacts & Tektites Dating the Clinchfield Formation
    • 14C: The Tivola Limestone
    • 14D: Twiggs Clay Vertebrates
    • 14E: Ocmulgee Formation Vertebrates
    • 14F; Sandersville Limestone, By Hank Josey
    • 14I: Dating Late Eocene Sediments
    • 14J: Georgia's Tektites; Georgiaites
    • 14K; Shell Bluff; Georgia's Most Historic Paleontology Site
    • 14L; Taylors Bluff, Paleo Paddling the Ocmulgee River
    • 14M; Eocene Terrestrial Mammals From Gordon, GA
    • 14N: Fossil Ridge, A Stratigraphic Study in Oaky Woods Wildlife Management Area
    • 14O; Georgia's First Entelodont
  • 15: Early Oligocene
    • 15A: The Marianna Limestone
    • 15B; The Glendon Limestone
    • 15C: Undiffereniated Oligocene Residuum
    • 15D; Brissus bridgeboroensis; A New Echinoid Species From Georgia’s Bridgeboro Limestone
    • 15E: The Curious Steinkern Sea Biscuits of Red Dog Farm Road
  • 16: Bonaire GA Entelodont
  • 17: The Whale Eating Shark
  • 18: Miocene Epoch; 23.3 to 5.3 Million Years Ago
    • 18A; Miocene Terrestrial Vertebrates
    • 18B; Paul Fell, Rockhouse Cave
  • 19: Pliocene Epoch; 5.3 to 2.5 Million years Ago
  • *NEW* 19A; Two Small Primitive Horses from Taylor County
  • 20: The Ice Ages; Pleistocene & Holocene Epochs
    • 20A; Clark Quarry's Mammoths & Bison
    • 20B: Pleistocene Vertebrate List
    • 20C: Georgia’s Eolian Dunes
    • 20D: Georgia’s Carolina Bays
    • 20E: Late Pleistocene Significant Events
    • 20F: Southeastern Thermal Enclave
    • 20G; Diamond Back Terrapins
    • 20H; A Kaolin Mine Beaver Dam
    • 20I; Pleistocene Vertebrate Fossils On Georgia’s Piedmont
  • *NEW* 20J; Watkins Quarry Pleistocene Vertebrates, Glynn County, GA
  • 21: Humans in Georgia
  • 22: Geology of the Coastal Plain, 1911
    • 22A: 1911 Cretaceous Fossil Locations
    • 22B: 1911 Eocene Fossil Locations
  • 23: Coastal GA Locations (1957)
  • 24: Needed; The Georgia Geologic Survey

1: Archaeocyathids;
Georgia’s Oldest Fossils At 513 Million Years Old
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By Thomas Thurman

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​Archaeocyathid
means "ancient cups" and they’re Earth’s oldest reef building organisms and at 513 million years old, Georgia’s oldest fossil. There were solitary species as well as reef-building ones. They occur in the Shady dolomite formation of the Cartersville mining district in Bartow County, Georgia.

The fossil is essentially two conical calcium structures, like nestled bowls or cones, connected by vertical walls. The structures are porous, it’s believed that water was drawn or pumped through the pores, nutrients filtered out, and the water expelled into the central cavity. It’s thought that the “body” of the living organism occupied the space between the walls.
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They’re extinct, and we know very little about the living animal but the earliest fossils come from Early Cambrian sediments 525 million years old, in modern Siberia. They diversified dramatically into over a hundred families but at about 516 million years ago they went into a sharp decline. The last known species, Antarcticocyathus webberi, met extinction near the end of the Cambrian about 490 million years ago and is known, as its name suggests, from Antarctica.
 
Some researchers consider them to be coralline sponges, but this is still a matter of debate. Sponges are known to occur at 580 million years ago. Archaeocyathids resist taxonomy and have yet to be properly assigned in the Linnaean scientific classification systems; another matter of ongoing debate.

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From the minds of many…
I want to thank Cam Muskelly, Bill Montante (Tellus Science Museum), Asa Kaplan and Burt Carter for their assistance on this page. These Northwest Georgia Valley & Ridge fossils are from a very different world than the sediments I usually work in south Central Georgia’s Coastal Plain. Muskelly introduced the topic on Facebook’s Georgia’s Fossils Group with the question; “Where can I find Archaeocyathids?”
 
Montante soon replied “These, as best we know, are Georgia’s oldest fossils. Stromatolites in Georgia are about the same time period... mid Cambrian series two, roughly 513 million years old. Part of an ancient patch reef structure located now in the Bartow County Cartersville mining district. Shady dolomite formation.”

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Asa Kaplan led me to the 1950 publication Geology and Mineral Deposits of the Cartersville District, Georgia by Thomas Kesler (1) where the Shady Formation is described.
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In 1950 Kesler suspected 5 genera of archaeocyathids occurred in the Shady Formation, referring to them as “coral sponges”. He reported that they were the formation’s most abundant fossil and had been reviewed by J. Brooks Knight and G Arthur Cooper of the United States National Museum (Smithsonian).  Knight and Cooper reported; “An undetermined archaeocyathid, Nisusia sp., Semicircularea sp., Helcionella cf., Helcionella rugosa.”
 
 References;
1.       Geology and Mineral Deposits for the Cartesville District, Georgia; Thomas Kesler, United States Department of Interior. Geological Survey Professional Paper 224, Pag 63, 1950; pubs.usgs.gov/pp/0224/report.pdf