Pleistocene Epoch

2 million to 10,000 years ago

The ice ages of the Pleistocene wreaked climatic havoc on the northern continents, but Florida was buffered from the worst effects by the warm waters of the Gulf of Mexico. Nevertheless, rapid pulses of climate change profoundly affected the area. During glacial periods (low sea levels), Florida was more than twice as large as it is today. Warmer periods (high sea levels) caused the peninsula to shrink in size.

The number of larger animals (megafauna) declined during the late Pleistocene, but scientists are unsure why these extinctions occurred. Changing climates or disease may have caused their demise. Perhaps the new predator in the region, Homo sapiens, hunted these marvelous animals to extinction. All we know with confidence is that their fossilized remains testify to their existence in Florida until about 10,000 years ago.

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

Transcript

We enter our final chapter, the time of the great Ice Age, when Earth’s climate fluctuated dramatically and with great frequency. Paleo-Indians entered the Americas in search of favorable climates and plentiful food. Their impact will forever change the planet.

This is the Pleistocene, a time in Earth history between 2 million and 10,000 years ago. During the Pleistocene glacial periods, temperatures plummeted over much of the world and parts of North America were literally uninhabitable. Extensive glacial sheets up to two miles thick covered much of the continent, stopping just about 900 miles north of Florida. At times during the Pleistocene, sea levels dropped over 300 feet causing Florida to double in size.

During interglacial times, Florida’s terrain and vegetation were probably much like that found in unaltered areas of North Florida today. This was ideal for inhabitants like mastodons and mammoths, making Florida as wild and diverse as any place on the planet. During low sea levels, the Great American Biotic Interchange between North and South America continued to allow new species to enter Florida along a broad coastal plain. Dramatic proof of these changing sea levels are found in the underwater caves of the Yucatan Peninsula. Elaborate cave formations, which can only form above sea level, are found here deep underwater.

Pleistocene fossils are found in almost every county in Florida, from the Panhandle to the Florida Keys. Fossils from over 1,000 such localities are archived in the collections of the Florida Museum of Natural History.

Sinkholes throughout Florida often act as traps collecting amazing assortments of Pleistocene megafauna. These localities provide evidence of a rich record of land and sea life during this time. Most of the great mega fauna, with the exception of the now endangered manatee, became extinct in Florida 10,000 years ago, leaving a far less diverse wildlife. Scientists still ponder the cause of this widespread extinction.

Perhaps no other place in the world had such a rich and interesting role in the Pleistocene Epoch as Florida. It was the last epoch of glorious extremes and its closure opens the door to our time. Enjoy the amazing fossil past of the Pleistocene Epoch here at the Florida Museum of Natural History.

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