Jones said: "This is the greatest honour of my Scarlets career - I am absolutely delighted to have been asked to be captain. If I can do half as good a job as Simon has done over the past five years, I will be pleased - he is a great Scarlet, had the respect of all the boys and has been an inspirational captain.
"We have been through a challenging time and last season was plagued by injuries, but this season brings a fresh new start and there is a very upbeat mood in the camp since we returned for pre-season, with a number of new faces joining us.
"We have got a good level of experience coming in with new arrivals like Sean Lamont and Rhys Thomas and exciting prospects like Richie Pugh, all of which will bring new impetus to our group. Also some of our younger rising stars have had great experience from the Wales tour this summer.
"Going forward I think we have a lot to be positive about, some of the younger guys have shown what they are capable of and we have a strong group of very experienced senior players who will have more of a role next season in helping take things forward. We need to take a collective interest in how our rugby is progressing and our top guys will have a bigger input in our training sessions next season."
On the new Scarlets vice-captain David Lyons, Jones added: "All the players have a great deal of respect for Dave, he's a typical Aussie easy going on the outside but with a tough, competitive edge - he will challenge everything and is not afraid to say what he thinks. He has a strong work ethic and this has a great influence on the team."
Lyons, who joined the region last season from the Waratahs said: "This is a great honour and I really appreciate it particularly given the proud tradition and great heritage that this club has.
"I am really looking forward to playing a bigger part in the how this team develops next season and takes its rugby forward. We have to be more consistent in what we do and we owe it to our supporters to put in 100% and I will be doing all I can to move us in the right direction.
"We have a good crop of talented young players, which gives us a lot to be excited and optimistic about going forward as we see their potential realised; they will have gained a lot from exposure in big games last season and that will help reap rewards for us as a team going forward."
Scarlets Head Coach Nigel Davies said: "We're really grateful to Simon Easterby and Stephen Jones for what they have done as captain and vice-captain and as two of our most experienced Scarlets players these will be big boots to fill. But I think Mark and David will bring a lot to the leadership of this new look team and lead by example and inspire our younger players.
"Like Simon, Mark Jones embodies everything that the Scarlets stand for. In addition to his talent and experience on the playing field has shown he has great pride and belief in the region's values and its playing ethos.
"David has had a major impact on this side from the very beginning and his commitment and professionalism has been an example to all. He has a wealth of experience and this new responsibility give him more scope to help develop talent within our squad."
Last season's Scarlets vice captain and British Lion, Stephen Jones congratulated Mark and David and said he believes they will be a good team partnership to lead the campaign next season.
"Mark is a true Scarlet and obviously I have known him for quite a while, he has proved himself as a great player on both the regional and international stage and will be a popular captain with team mates and our supporters. He has plenty to give, is very motivated and has great passion about our rugby region.
"There is no doubt David is a very intelligent rugby player and will pass on a lot of his experience and motivation to the younger group of players that are coming through. He works hard on his rugby, is very committed and will lead by example.
"I think they will do a great job. I'm looking forward to a bit of time off after the Lions Tour and then joining up back up with my Scarlets colleagues."