Twenty-eight-year old Vaughton is the most experienced of the quartet, having chalked up 63 appearances in an Ospreys shirt and scoring 11 tries since signing from Cardiff Blues in the summer of 2005. Having featured in the historic win over Australia at the Liberty Stadium in 2006, and the EDF Energy Cup Final win over Leicester at Twickenham in 2008, he made his final appearance for the region against Edinburgh at Murrayfield in March.
A product of the Ospreys development system, 25-year old Shervington has 38 appearances to his credit since his debut in 2006 including a brief outing off the bench in last Saturday's Magners League Grand Final, with a single try coming in the Heinken Cup against Benetton Treviso last season.
Liam and Ross Davies both depart after just a season with the Ospreys having signed for the region last summer. Scrum-half Liam signed from French side Brive, and made four appearances in the early part of the season before going on loan to London Welsh, while tighthead Ross made just two appearances after signing from Sale Sharks, before a fractured fibula and ligament damage ended his season prematurely.