Livingston won world bronze in 2007 and competed in the Beijing Olympics
Beijing Olympian Katy Livingston has missed out on a return to China for next week's World Championships.
Livingston, 26, from Cleveland, won a world bronze in 2007 but has struggled since the introduction of a combined run/shoot format last season.
Mhairi Spence, who won the UK leg of the World Cup in April, has also been left out of a young squad for Chengdu.
Katy Burke, Samantha Murray and Freyja Prentice, who won world junior gold two weeks ago, have all been selected.
They are joined by Beijing silver medallist Heather Fell, who has regained form this year, having also struggled when the new format was brought in following the 2008 Games.
There will be two generations of athletes in one team and I think that's very positive for us
GB performance director Jan Bartu
"The women athletes selected were the top four in the rankings," said GB performance director Jan Bartu.
Sam Weale returns to action following his silver medal at the European Championships in Hungary last month - the first European individual medal won by a male British pentathlete.
He is joined in the squad by fellow Olympian Nick Woodbridge and 19-year-old Jamie Cooke.
They will be in action on Wednesday 1 September, aiming for a place in Friday's final. The women's final takes place the following day.
"We have a mix of experienced Olympic Games athletes and some new kids that will be on the start line for the first time at this level. All of them have earned their places," Bartu added.
"There will be two generations of athletes in one team and I think that's very positive for us.
"It will be a really tough competition. We're looking for a top-eight finish in both genders."