Cross is aged 22 and is a centre or half-back while 23-year old McCloskey is a 6 foot 7 (200cm) tall prop weighing in at almost 19 stone.
Both players started their Rugby League career with Irish club Treaty City Titans and both made “A” international appearances last year.
St Helens then attended Rugby League Ireland‘s inaugural Talent Identification Academy that took place in Limerick last May where both players were identified as potential future stars. They were given a trial by Saints and then taken on full-time.
After making appearances for the St Helens under 20s in the latter part of 2011, they were both loaned out to French club Montpellier Red Devils for part of their recent winter 2011-12 season.
North Wales Crusaders coach Clive Griffiths said: “Aaron and Ian are two welcome additions to our squad. Saints think lot of them so we know that they must be good. It is a big benefit to us to add a powerful back and a strong forward and we know that they will do a very good job for us. They are two players who show great promise and we’re looking forward to seeing them in action.”