The Bucs made the announcement Monday, a day after a season-ending 42-17 loss to the New Orleans dropped Schiano's record to 11-21 over two seasons.
"The results over the past two years have not lived up to our standards and we believe the time has come to find a new direction," Bucs co-chairman Bryan Glazer said in a brief statement.
"Mark has been a valued member of our organization for two decades and we respect the passion he showed for the Buccaneers during his time here," Glazer added. "We thank Greg for his hard work and effort the past two seasons, but we feel these moves are necessary in order to achieve our goals."
The Bucs announced the firing less than 30 minutes after closing the locker room, where players were clearing out their locker. The team met with the coaching staff earlier in the day and had not been informed of the dismissals before media was allowed into the locker room.
Tampa Bay lost the first eight games of the season while going through a messy split with former quarterback Josh Freeman and an outbreak of MRSA infections in the locker room.
Schiano was hired in January 2012, leaving Rutgers to take over a team that ended its final 10 games under Raheem Morris on a 10-game losing streak. He inherited one the NFL's worst defenses, but also a young quarterback in Freeman, who won 10 games in his first full season as a starter and became the franchise's first 4,000-yard passer in Schiano's first year in Tampa Bay.
But Freeman's relationship with Schiano soured when the Bucs dropped five of the final six games of 2012, with Freeman's inconsistency contributing to the slide. The fifth-year quarterback was benched after an 0-3 start this season, replaced by rookie Mike Glennon.
Dominik was promoted to general manager in 2009. The team went 28-52 in five years under his direction.
The Bucs have not made the playoffs since 2007. They haven't won a postseason game since their 2002 Super Bowl run that produced the franchise's only Super Bowl title.
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