Howdy! For those that are interested, check out this National Geographic post on a new, 290 million year old amphibian they think may be the missing link in that particular family tree.
http://news.nationalgeographic.com/news/2008/05/080521-frog-fossil.html
So, nifty stuff! I know NatGeo doesn't always publish the "newest" of materials, but I hadn't read this on before.
-Erin