-80/Super 80 project was started long after the merger. The name was changed during production and A simply chose not to adopt it.
The "screwdriver tail", or the Beaver Tail as MDD called it, was adopted in 1986 for all variants of the MD
-80 except the MD
-81, of which only a few more were built. Many of the older MD
-80s have been refitted with this tail cone type, but most still use the original cone.
-80, Super 80, and DC-9-80, it's all the same.
Those who fail to learn history are doomed to repeat it in summer school.