In one of those moments that make us wonder if it's April Fools Day, Megadeth frontman Dave Mustaine has announced that original bassist Dave Ellefson is back in the band and will embark on Megadeth's month-long 'Rust in Peace' 20th Anniversary Tour, which begins March 1 in Spokane, Wash. and runs through March 31 in Hollywood, Calif. The shows will feature Megadeth performing 1990's 'Rust in Peace' in its entirety. Megadeth will be joined on all dates by Testament (performing their first album 'The Legacy' in full) and Exodus.

The reunion comes as a bit of a surprise, because after Ellefson left the band in 2002, he and Mustaine became entangled in an ugly battle over band royalties and rights to the group's name. In 2004, Ellefson filed an $18.5 million lawsuit against Mustaine, which was dismissed on Jan. 13, 2005.

"This shows the power of brotherly love and forgiveness," Mustaine said. "David Ellefson belongs in Megadeth. Next, we are going to show you the power of getting your asses kicked -- hard!"

The Megadeth lineup for the 'Rust in Peace' reunion tour will feature Mustaine, Ellefson, guitarist Chris Broderick and drummer Shawn Drover.

"This is a huge moment for all of us, band and fans alike," added Ellefson, who formed his own group F5 after leaving Megadeth. "It is a great celebration of the music from one of the biggest landmark albums of our career."

The return of Ellefson means the departure of bassist James LoMenzo, who joined Megadeth in 2006. "We'd like to thank James LoMenzo for several years of loyal service on the bass, and wish him the very best," Mustaine said.

LoMenzo has yet to comment.