This, this is Diplocaulus
A lepospondyl amphibian
Praise, praise, praise to Ron Pine:
He won himself the blue ribbon.
Unfortunately, the commenting system here broke over the weekend. (It is being fixed now.) Dan Phelps was the first person to e-mail the correct answer to the NCSE office, but Ron Pine already posted the correct answer on Facebook. (Most of the Facebookers thought that it was Tiktaalik.)
(A tip of the beribboned hat to Steven Newton, who took the photograph.)