Close to 150 people were killed in clashes at a university campus in the country.
The senior leader, known as Abdishakur Tahlil, was killed near Saakow, Somalia.
The Defense Department said it is still assessing the results.
The panel was disbanded after the 9/11 attacks led the U.S. to focus its attention overseas.
The U.S. military secretly deployed trainers and advisers to Somalia in October.
The Pentagon called it a "significant blow" to al Shabaab, al Qaeda's Somali affiliate.
The White House called Ahmed Godane's death a "major" loss for al Qaeda.
Military means are proving less than adequate in the fight against Islamic extremism.
The proposed NDAA rejects many of the Pentagon's preferred spending cuts.
A suspected U.S. drone strike killed at least two al-Shabaab insurgents in Somalia on Monday,...