Oligocene Epoch

34 million to 24 million years ago

Global climates became cooler during the Oligocene, causing sea levels to drop. At least the northern portion of the Florida platform, once abundant with tropical, marine habitats, was now land.

Early immigrants to the Florida peninsula included amphibians, reptiles, bats, shrews and rabbits. Also, predators tracked dwarf horses and the strange, hoofed mammals, oreodonts and chalicotheres, onto this new land. In the ocean, huge sharks plied the depths, while several kinds of sea cows were abundant near shore.

Video produced, directed and filmed for the Florida Museum of Natural History by Wes C. Skiles/Karst Productions, Inc.

Transcript

The grand Eocene has passed, and great changes blow in the winds. Global climates become cooler and drier, and many of the ocean’s greatest creatures disappear. Florida is still mostly a shallow underwater sea, but this is about to change.

This is the Oligocene Epoch, 34 to 24 million years ago. Oligocene sediments are found in Florida in isolated pockets. Hidden inside these limestone and clay deposits are great mysteries. Many of the great creatures of the Eocene had disappeared from Florida’s shallow seas and new marine species are evolving, now becoming more like today’s marine life. The great primitive whales are now gone, but new different species appear. New sharks also evolved. The dugong, a relative of the manatee with flipper-like forelimbs and a deeply notched tail became more prevalent in Florida.

On land, this was a time of great change. Cooler temperatures caused the polar ice caps to trap great quantities of water from the world’s oceans. In Florida, sea levels fell, exposing part of the peninsula for the first time. Today, paleontologists from the Florida Museum of Natural History are cataloging important discoveries from the Oligocene. These pieces of miniature horses, camels, bear dogs, frogs, and tortoises were found during the construction of Interstate 75 near Gainesville and represent the earliest known land-dwelling animals to enter Florida.

Some of the most spectacular evidence of Oligocene land life in Florida was collected locally along the Suwannee River. Florida Museum of Natural History scientists excavated several skeletons of a previously unknown species of an extinct plant-eating oreodont. These strange pig-like beasts were extremely rare in Florida. All these discoveries provide our scientists with proof that for the first time during the Oligocene, a terrestrial connection between the mainland Southeast and Florida allowed land dwellers to make Florida their home. Take time to enjoy the fossils of the Oligocene representing Florida’s first true land dwelling natives.

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