There’s a new episode PBS Eons.  This one is about the evolution of a flexible trunk in elephants.

Long-jawed proboscideans were doing pretty well for themselves. That is, until they were all rapidly replaced with proboscideans with long, flexible trunks instead: mammoths, mastodons, and our modern elephants. What suddenly made long jaws such a liability? Well, it looks like we can thank a changing climate for the evolution of the elephant’s trunk.