Career
He was signed by the Philadelphia Eagles as an undrafted free agent in 2011. He played college football for Southern Arkansas. Philadelphia Eagles
Thornton signed by the Philadelphia Eagles as an undrafted free agent following the 2011 NFL Draft and NFL lockout.
He initially made the 53-man roster after training camp to open the season, but was waived to make room for offensive lineman Kyle DeVan on September 4.
He was re-signed to the team"s practice squad the next day and spent the first thirteen weeks of the season on the practice squad. He was promoted to the team"s active roster on December 12.
Thornton"s playing time increased significantly in 2012. In 2013, Thornton emerged as the Eagles starting defensive education
Dallas Cowboys
On March 10, 2016, Thornton signed with the Dallas Cowboys on a four-year deal worth more than $18 million with $6 million guaranteed.