Super Deltas are very similar to Halfmoons but have less than a 180 spread when flared. They are nearly a

Super Delta Tail
Black orange betta-sd
Originated From: Thailand
Approximate Petstore Cost: Not Sold In Petstores
Fin Type: See Below
Halfmoon but not quite. Super Deltas are differentiated from Veil Tails by the fact that if you drew a line from the nose to the tip of the caudal fin on a Super Delta there would be an equal amount of fin on either side of the line, whereas on a Veil Tail there would be little tail at the top, and the majority below.

(Taken from here)