Are there any rear derailleurs compatible with Shimano Tourney RD TX 80 I need a new rear derailleur for my Claud Butler Urban 200.

I have looked at the old one and can see it is a Shimano Tourney RD TX 80 -7.

I have found these quite hard to get and I am wondering if there are any other models that would be compatible for my bike? 

Any ideas?

Thanks
You just need a 7 Speed derailleur? Shimano RD-TX35 7spd should work it is the current derailleur used on the bike as it is specd. HEREBut I would also go to your LBS and have them see, they might have a better ability to locate the same one you were using.