Does brain size matter?

I was rather taken this morning by this chart from the laboratory of Suzana Herculano-Houzel. As always, click on it to enlarge.

The labels and the twigs of the tree seem to have a come a little unstuck in places, but otherwise a nice piece of work. Who would have thought that anteaters would do so well?

PS: in the margins of the chart I found out about a new-to-me operation at http://www.ted.com/ - on which she does rather well too.