Exploring Georgia's Natural History
  • Natural History & Geology
    • Podcast; The Tivola Whale
    • Coastal Plain Correlation Chart
    • GA Paleo Research by Paul F. Huddlestun PhD >
      • Late Eocene & Older... Coastal Plain Stratigraphy
      • Washington County Core Logs By Paul Huddlestun
      • Coastal Plain Core Logs by Paul F. Huddlestun
    • Presentation; Oaky Woods Stratigraphy
    • Physiographic Map of Georgia
    • Fossils of Oaky Woods
    • Collections & Stewardship of Georgia’s Fossils
    • I, Periarchus (A Fossil's Tale)
    • 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
      • Bill Christy; Kamin Performance Minerals Fossils
    • Public Fossil Locations >
      • South Houston County Fossils
      • Updated; Islands of the Savannah River
    • Georgia Fossils in the Smithsonian
  • Education Material
    • My Field Kit; What You Need In The Field
    • Meet Crassostrea gigantissima, Georgia's Historic Giant Oyster
    • Georgiacetus Presentation; A Whale for Georgia
    • The Natural History & Fossils Record of Houston County, GA
    • Evolution in Georgia's Fossil Record
    • Georgia's State Fossil; Shark Teeth
    • Georgia's Paleontology For Georgia's Classrooms
    • SW GA RESA 2018 Talk
    • Library & School Presentations
    • An Introduction To Fossils; Presentation
    • Georgia's Fossils Presentation; 500 million years
    • Georgia College Natural History Museum
  • Meteorites
    • Did I Find A Meteorite?
    • Georgia's Lost Meteorite
    • Georgia's Witnessed Meteorite Falls
    • The Sardis Iron, Georgia's Largest Meteorite
  • 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
    • 5B: Carpentertypus durhami, Georgia’s Giant Insect, 315 Million Years Ago
  • 6: 200 Million Years Ago
    • 6A: Birth of the Atlantic Ocean
  • 7: Cretaceous Georgia, Dinosaurs & more
    • 7A: Georgias Pterosaur
    • 7C: Coelecanths
    • 7B: So Many Sharks
    • 7D: Xiphactinus vetus
    • 7E: Side-necked turtles
    • 7F: Marine Reptiles
    • 7G: Dinosaurs in Georgia
    • 7I; The Blufftown Formation
    • 7L: Bill Montante's Mega "Gator" Tooth Discovery
    • 7K: The Pio Nono Formation
    • 7J: The Eutaw Formation
    • 7H: Deinosuchus schwimmeri in Recognition of Dr. David Schwimmer
  • 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 (Revised)
    • 12D: Chrysocetus
    • 12E: The Redmond Mandible of Albany Ga
    • 12F; Houston County, GA 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
    • 14F; Sandersville Limestone, By Hank Josey
    • 14E: Ocmulgee Formation Vertebrates
    • 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
    • 14P: Historic Rich Hill
    • 14Q; Bibb County's Christy Hill, Clinchfield Formation Hilltop
  • 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
    • 15F: Early Oligocene Gordian Knot
  • 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
    • 18C: The Marks Head Formation
    • 18D: Miocene Terrestrial Vertebrates of the Marks Head Formation
    • 18E: The Statenville Formation
    • 18F: South Georgia’s Dugong Metaxytherium calvertense
  • 19: Pliocene Epoch; 5.3 to 2.5 Million years Ago
    • 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
    • 20J; Watkins Quarry Pleistocene Vertebrates, Glynn County, GA
  • *NEW* 20K: Pleistocene Vertebrates from Coastal Georgia
  • 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
  • Building This Site
    • Origins Of This Site
    • Contributing Artists
    • Black & White Sketches

5: Georgia Before The Dinosaurs

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Dr. Burt Carter fielded my question about possible Georgia vertebrates between our 450 million year old Astraspis and the rise of the dinosaurs (Late Triassic; about 230 million years ago).

He reports that in the northwest part of Georgia you’ll find our Ridge and Valley Region; rugged, buckled terrain created from sediments laid down flat, then buckled during long-ago impacts from continental drift.

The terrain buckling happened when the North American continent collided with Gondwana, (specifically; the African continent) about 300 million years ago.  The resulting supercontinent became Pangaea. This was a key event in the raising of the Appalachian Mountains, near the center of Pangaea.

The same old Appalachian Mountains which start today in North Georgia and reach up the East Coast of the USA.

As far as vertebrate fossil from this time frame, Dr. Carter explains;

“Though I haven’t seen and don’t know of reported finds, there are probably terrestrial amphibian and reptiles fossils in Georgia’s 300 to 318 million year old sediments. Vertebrate tracks are reported in the same rocks of northeast Alabama. There is no known reason why similar finds couldn’t appear in Georgia.” 

Amateurs and enthusiast have long collected ancient invertebrate and plant fossils from Northwest Georgia; corals, crinoids and ferns are among some of the popular finds. 

The author has a 300 million year old fern fossil recently collected by amateur paleontologist Tom Batcha, another member of the Mid-Georgia Gem and Mineral Society. The specimen came from Durham, Georgia in Walker County.

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Georgia's Volcanoes
At this point in Georgia’s history volcanoes appeared in our state and though most have long ago eroded away the evidence of their presence can be seen in the varied mineral deposits of places like Graves Mountain in Lincoln County, Georgia. Graves Mountain is a popular mineral collecting site for Georgia’s rock clubs. 

It’s very likely that there are other, more recent, Georgia volcanoes buried deep beneath our Coastal Plain.  Dr. Carter spoke at a 2012 meeting of the Mid-Georgia Gem and Mineral Society and mentioned magnetic anomalies on the Coastal Plain in passing during a talk on the Suwannee Current and Gulf Trough.

Tifton, in South Georgia, sits about 65 miles from the nearest coastline and is about 109 meters (360ft) above sea level. The sediments below Tifton reach 1,525 meters (5,000ft) vertically before you encounter bedrock. 

That’s nearly 1400 meters (4,600ft) below sea level. 

This bedrock dates to the Triassic Period; at least 200 million years old and hosts large magnetic anomalies which probably represent ancient, extinct volcanoes.

Originally described in 1974, anomalies create a magnetic disturbance, such as a large deposit of igneous material might. The theory that these are volcanoes is supported by intrusions of magma, or magmatic dikes, in local sediments. 

I asked Scott Harris at Fernbank Science Center in Atlanta about these anomalies. His reply was simple: “It's well-established that there are voluminous flood basalts of the earliest Jurassic beneath the Coastal Plain sediments.” 

Flood Basalts are large areas covered with basalt lava. Scott Harris pointed out that Dr. Tim Chowns at the University of West Georgia had researched these anomalies in detail.

Georgia’s geologic history is full of surprises.


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The Global Perspective
During the Devonian Period (416 to 359 million years ago) the vertebrates took to land; four limbed terrestrial vertebrates, the tetrapods, emerge into the fossil record. Tetrapods include birds, reptiles, amphibians and our own mammal class. 

The earliest tetrapods were the amphibians.

Amphibians overcame the problems of walking on land and breathing atmosphere; they were (and are) still tied to the water, their soft shelled eggs require water or at least heavy moisture and their skin must also be kept moist. 

Some members of the amphibian class became large predators; specifically the order Temnospondyli saw amphibians reaching up to 9 meters (29.5 feet) in length; this was the alligator-like Prionosuchus which lived in Brazil about 270 million years ago. I say alligator-like as Prionosuchus is more closely related to modern salamanders than alligators.

Reptiles emerged from the amphibians. Their eggs were (and are) sealed, making them capable of surviving without water. Their thicker scaled skin seals their bodies and allows them to retain moister. 

The reptiles gave rise to the dinosaurs which were a wonderful evolutionary success enduring for more than 150 million years and diversifying wildly. 

Reptiles also gave rise to the synapsids at about 300 million years ago, which, in time, produced mammals and eventually; human line of primates. 

At about 260 million years ago the cynodonts emerged, our family tree though there are many more branches to go before monotremes, marsupials, placental mammals, primates and eventually mammals come along. 



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The Permian-Triassic Extinction Event 
Extinction events are large scale die-offs of multiple species; they can be local, regional or global. Here we’re discussing a terrible, global event. There are five, major, global extinction events recorded in the Earth’s fossil record. There are many lesser extinction events. The Permian-Triassic Extinction Event is by far the most serious and came close to erasing advanced animal life on Earth.

About 251 million years ago 96% of all marine species and 70% of all terrestrial species globally disappeared from the fossil record forever. 

Furthermore; this is the only known extinction event in Earth’s history which dramatically impacted the insects. Even plants, which are usually resistant to extinction events, were impacted. There are no reliable numbers about the loss of plant species and a great deal isn’t known about how many species existed before and after, but it is evident that there was a mass rearrangement of plant distributions and abundances. 

What triggered the Permian-Triassic Extinction Event is also unknown and very little is known about what actually happened, however the event occurred in a series of phases which still defy explanation.

Recovery to the previous levels of biodiversity took upwards of ten millions years.


References;
Personal communication with Dr. Burt Carter, Georgia Southwestern State University.
Personal Communication with R. Scott Harris, Fernbank Science Center.