In the fifth of an eight-part series, we take a look at the most notable fourth-round draft picks in Bears history.

Over the last four decades or so, the Bears have selected several players in the fourth round of the draft who developed into key long-term contributors.

That includes three members of the franchise's last Super Bowl team in 2006: Defensive end Alex Brown (2002), cornerback Nathan Vasher (2004) and quarterback Kyle Orton (2005).

Brown spent his first eight NFL seasons with the Bears, appearing in 127 games with 107 starts and recording 43.5 sacks and five interceptions. He ranks fourth on the team's all-time sack list behind only Richard Dent, Steve McMichael and Dan Hampton.

Vasher played his first six NFL seasons with the Bears, appearing in 87 games with 51 starts and registering 20 interceptions and two forced fumbles. The Texas product was voted to the Pro Bowl in 2005 after leading the Bears with a career-high eight interceptions. Vasher also set an NFL mark in 2005 that teammate Devin Hester matched a year later by returning a missed field goal 108 yards for a touchdown.

Orton spent his first three NFL seasons with the Bears before being traded to the Denver Broncos in a 2009 deal that sent Jay Cutler to Chicago. After Rex Grossman broke his leg during a 2005 preseason game, Orton took over and compiled a 10-5 record as the starter, helping the Bears win their first NFC North title.

Several Bears fourth-round picks excelled in the 1990s. They include guard Todd Perry (1993), running back Raymont Harris (1994), receiver Marcus Robinson (1997) and linebackers Rosevelt Colvin (1999) and Warrick Holdman (1999).

Perry spent his first eight NFL seasons with the Bears, appearing in 118 games with 97 starts from 1993-2000. He started all 16 games at left guard during his final three years with the team.

Harris spent his first four pro seasons with the Bears, rushing for 2,245 yards and 15 touchdowns on 592 carries and catching 100 passes for 651 yards and 1 TD from 1994-97 while appearing in 42 games with 35 starts. The Ohio State product rushed for a career-high 1,033 yards and 10 TDs in 1997.

Robinson played his first five NFL seasons with the Bears, catching 187 passes for 2,695 yards and 20 touchdowns in 51 games with 28 starts from 1998-2002. He set a franchise single-season record that has since been broken with 1,400 yards and nine touchdowns on 84 receptions in 1999.

Colvin and Holdman arrived together in 1999 and were joined a year later by Brian Urlacher, forming one of the NFL's top young linebacking corps. Colvin spent his first four seasons with the Bears, recording 26 sacks and 10 forced fumbles. Moving to defensive end in passing situations, he compiled 10.5 sacks in both 2001 and 2002. Holdman played five seasons with the Bears, registering 3.5 sacks and seven forced fumbles.

Two key members of the 1985 Super Bowl championship team were fourth-round picks: Guard Tom Thayer (1983) and kicker Kevin Butler (1985). Thayer was a key member of some of the best offensive lines in NFL history, appearing in 123 games with 120 starts over eight seasons with the Bears.

Butler was the franchise's all-time leading scorer with 1,116 points until Robbie Gould broke the record last season. Butler appeared in 184 games over 12 seasons with the Bears. He still holds the NFL single-season rookie scoring record with 144 points set in 1985 with the Super Bowl XX champions.

Other notable Bears fourth-round picks include:

James Thornton, tight end (1988)
Nicknamed "Robocop" due to his impressive physique, Thornton caught 75 passes for 1,059 yards and five touchdowns in 64 games over four seasons with the Bears from 1988-91.

Todd Bell, safety (1981)
Bell spent his first six seasons with the Bears from 1981-87, though he sat out the entire 1985 Super Bowl season due to a contract dispute. In 1984, the Ohio State product was voted to the Pro Bowl after recording four interceptions. Bell delivered a devastating hit in the Bears' playoff win over the Washington Redskins later that season on running back Joe Washington, forcing an incompletion.

Virgil Livers, cornerback (1975)
Livers spent his entire five-year NFL career with the Bears, recording 12 interceptions and six fumble recoveries while also averaging 8.6 yards on 86 punt returns and 20.1 yards on 27 kickoff returns.

Doug Buffone (1966)
One of the most popular Bears players during and after his career, Buffone played 14 seasons in Chicago, tied for second most with linebacker Bill George behind long-snapper Patrick Mannelly (16). Though overshadowed by teammate Dick Butkus, Buffone was a playmaker whose 24 career interceptions are the most in Bears history by a linebacker.