Twenty-one-year-old Durham-born central defender Elsdon joins having spent his youth career at Championship side Middlesbrough.
The 6`2” defender started his early youth career as a striker at Sunderland before joining Middlesbrough’s academy at the age of 14, where his natural defensive talent was discovered.
He rose through the ranks at the Riverside Stadium and became a regular for them in the Premier League 2, featuring in every game of their 2015/16 UEFA Youth League run, including games against the likes of Torino, Dynamo Kiev and Paris Saint Germain.
He was part of the Boro under-21 squad who won the treble of the league, North Riding Senior Cup and the Development League Cup in the 2014/15 season. He also featured several times for Middlesbrough under-23’s in the Football League Trophy.
Last season he had a spell on loan at Inverness Caledonian Thistle where he made eight appearances for the Scottish Championship side.
He has four England under-17 caps to his name, having featured for the Three Lions in the 2013 Nordic Under-17 Football Championship.
Turner impressed during the first half of Tuesday night`s 3-1 win over Carlisle United.
Preston-born Turner, 22, started his career at Preston North End and Lancaster City before joining Stockport County.
In January 2014 he joined Oldham Athletic for an undisclosed fee, signing an eighteen-month contract at Boundary Park.
Turner made 22 appearances for Oldham and had loan spells at York City and Macclesfield Town before joining Morecambe in 2016, signing a two-year deal.
He spent the latter half of last season back at Stockport County on loan as they made the National League North play-offs.
He joins the Bluebirds on a one-year deal.