Earlier this year, as I ran around the Royal Ontario Museum fossil halls trying to take in as much as I could in the short time I had before a talk, an Ice Age fossil stopped me in my tracks. It was a fossil horse jaw, but unlike any I had seen before. The fossil seemed impossibly black, tooth and bone stained to gorgeous ebony shades.

The beautiful fossil had been excavated decades before from a tar seep in Talara, Peru. I had never heard of this place before. When I think “tar pit”, I think La Brea. (Perhaps because, aside from being the most important fossil site on the planet, La Brea translates directly to “the tar.”) But