Tiling the Plane... Again!

Well, this is sort of neat news: discovery of a new (15th) convex pentagon that successfully tiles the plane:

https://plus.google.com/u/0/100003628603413742554/posts/JC8hqyUHuDE

 If you don't know the history of this problem you can check out the Wikipedia article that is linked to in the above piece. Following additional findings after Martin Gardner originally drew attention to the problem back in the 1970s, the number of such tiling forms had stood at 14 for 30 years!
How many more are there???