This is it—the final matchup. We started with 32 potential names for our hypothetical placental ancestor. Now we’re down to two: Mancestor and Shrëwdinger. Which will it be? It’s your decision. Cast your vote now and give this creature a name!

What does it mean to be a 21st-century American naturalist? On Tuesday, April 9, join moderator Tom Brokaw and panelists Douglas Brinkley, a Roosevelt biographer; Lisa Graumlich, scientist and dean at the University of Washington's College of the Environment; Michael Novacek, senior vice president and provost of science at the Museum; and Rick Ridgeway, vice president for environmental initiatives at Patagonia, for Conservation, Wilderness, and the American Dream, a special event about the close links between American identity and natural heritage, as well as the role today's naturalists can play in conservation.

It's down to just a final, furry 4 potential nicknames for our hypothetical placental ancestor! Vote for the two finalists now.

Okay, just 8 possible nicknames left. Does our hypothetical common placental ancestor look more like a Placentor or a Mancestor? Nova or Hypotheshrew? Make your vote today for a final, furry 4!