Frozen into the stone floor of a stairway landing, several flights up in Columbia’s Lewisohn Hall, sits a stark reminder of how life has evolved in the sea. In Part 6 of the Columbia Geology Tour, David Walker of the Lamont-Doherty Earth Observatory takes us back to the Ordovician period, 450 million years ago, and paints a picture of the life of an ancestor of today’s nautilus and squid.
Coming next week: Resting beneath the iconic Alma Mater statue, a lesson in carbon sequestration. (You can watch all of the videos on YouTube here.)
