Not so long ago, the Delaware River froze for much of the year and the air packed an Arctic chill.
We’re not talking about several decades ago, before the planet began to warm at a relatively rapid pace due to human activities. We’re talking about the Late Pleistocene, 20,000 years ago when walruses lounged on the beaches at the Jersey Shore and ice covered much of the world.
Today Atlantic walruses are only found from northeastern Canada to Greenland, while Pacific walruses inhabit the northern seas off Russia and Alaska.
“In paleontology you see a lot of natural changes, but it also represents a lot of time — thousands to millions of years,” said Vertebrate Paleontology Collection Manager Ned Gilmore. “The Philadelphia-South Jersey watershed looked very different than it does today.”
The Academy’s Vertebrate Paleontology Collection of more than 26,000 specimens holds clear evidence of change — from climate to evolution to geological and beyond.
For example, this lower jaw belonged to a walrus that 20,000 years ago was swimming up the frozen waterbody that is now the Delaware. It was found in a dredge spoil pile near the Tacony-Palmyra Bridge and now is preserved at the Academy.
The Vertebrate Paleontology Collection and its reams of data are invaluable and available to students and researchers around the world studying a multitude of issues including climate change, species decline, evolution and extinction.
By Carolyn Belardo
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In the Academy’s “Spotlight on the Collections” series, we tell stories about specimens chosen by our scientists and also how researchers and others around the world depend on our collections for issues involving climate change, water quality, evolution, and biodiversity and extinction.
To read previous installments in the “Spotlight on the Collections” series, visit: