What period of the mesozoic era did birds first appear?

The earliest known birds appeared during the Jurassic Period of the Mesozoic Era, approximately 150 million years ago.

Thats what google said, sooo you decide what you want to do. :) Good luck!

supercell thunderstorms are perhaps the most violent of all thunderstorm types, and are capable of producing damaging winds, large hail, and weak-to-violent tornadoes