Three-times 200 metres winner Allyson Felix is among eight defending champions named in a powerful 129-member US world championships team announced by USA Track & Field (USATF) on Wednesday.

The versatile Felix will attempt to become the first woman to win gold medals at both 200 and 400 metres in a world championship during the Aug. 27-Sept 4 competition in Daegu, South Korea.     

    “I think it is going to be extremely difficult but I am excited to challenge myself,” Felix told Reuters in a recent interview.     

    She also hopes to run on both the 4x100 and 4x400 metres relays, where she won gold in 2007 .     

    One of her chief rivals in the 400 will be defending world champion Sanya Richards-Ross, who on Saturday ran the year’s second fastest time.     

    Olympic and world men’s 400 metres champion LaShawn Merritt, who recently completed a 21-month doping suspension, also returns.     

    Five other 2009 world champions will be back for the Americans — 400 metres hurdler Kerron Clement, shot putter Christian Cantwell, decathlete Trey Hardee, and long jumpers Dwight Phillips and Brittney Reese.     

    The team also has seven world leaders for 2011 in Reese, hurdler David Oliver, decathlete Ashton Eaton, high jumper Jesse Williams, women’s sprinters Carmelita Jeter (100) and Shalonda Solomon (200) and pole vaulter Jenn Suhr.     

     Both Jeter and Walter Dix, the double Olympic bronze medallist, will tackle the 100-200 metres double against Jamaica’s talented sprinters.     

     The US 100 metres team and 4x100 metres relay pool also includes former Olympic and world champion Justin Gatlin, who finished runner-up to Dix in his second year back from a four-year doping suspension.

US team (* denotes 2009 world champion):

MEN

    100: Walter Dix, Justin Gatlin, Michael Rodgers.

    200: Dix, Darvis Patton, Jeremy Dodson.

    400: LaShawn Merritt*, Tony McQuay, Greg Nixon, Jamaal Torrance.

    110 hurdles: David Oliver, Aries Merritt, Jason Richardson.

    400 hurdles: Kerron Clement*, Jeshua Anderson, Bershawn Jackson, Angelo Taylor.

    800: Nick Symmonds, Khadevis Robinson, Charles Jock.

    1500: Matthew Centrowitz, Leonel Manzano, Andrew Wheating.

    3000 steeplechase: Billy Nelson, Dan Huling, Ben Bruce.

    5000: Bernard Lagat, Chris Solinsky, Galen Rupp.

    10000: Rupp, Matt Tegenkamp, Scott Bauhs.

    20km walk: Trevor Barron.

    Hammer: Kibwe Johnson, Michael Mai.

    Discus: Jarred Rome, Jason Young, Lance Brooks.

    Javelin: Mike Hazle.

    Shot put: Christian Cantwell*, Adam Nelson, Reese Hoffa, Ryan Whiting.

    Pole vault: Derek Miles, Jeremy Scott, Mark Hollis.

    High jump: Jesse Williams, Dustin Jonas, Erik Kynard.

    Long jump: Dwight Phillips*, Marquise Goodwin, Claye, Trevell Quinley.

    Triple jump: Christian Taylor, William Claye, Walter Davis.

    Decathlon: Trey Hardee*, Ashton Eaton, Ryan Harlan, Bryan Clay.

    Marathon: Nick Arciniaga, Mike Morgan, Sergio Reyes, Jeffrey Eggleston, Mike Sayenko.

    4x100 relay pool: Dix, Gatlin, Rodgers, Trell Kimmons, Ivory Williams, Travis Padgett.

    4x400 relay pool: Merritt, McQuay, Nixon, Torrance, Michael Berry, Miles Smith.

    WOMEN

    100: Carmelita Jeter, Marshavet Myers, Miki Barber.

    200: Allyson Felix*, Shalonda Solomon, Jeter, Jeneba Tarmoh.

    400: Sanya Richards-Ross*, Felix, Francena McCorory, Debbie Dunn.

    100 hurdles: Kellie Wells, Danielle Carruthers, Dawn Harper.

    400 hurdles: Lashinda Demus, Queen Harrison, Jasmine Chaney.

    800: Alysia Montano, Maggie Vessey, Alice Schmidt.

    1500: Morgan Uceny, Jenny Simpson, Shannon Rowbury.

    3000 steeplechase: Emma Coburn, Bridget Franek, Delilah DiCrescenzo.

    5000: Molly Huddle, Amy Hastings, Lauren Fleshman.

    10000: Shalane Flanagan, Kara Goucher, Jenn Rhines.

20km walk: Maria Michta.

    Hammer: Jessica Cosby, Amber Campbell, Jeneva McCall.

    Discus: Stephanie Brown-Trafton, Aretha Thurmond, Gia Lewis-Smallwood.

    Javelin: Kara Patterson, Rachel Yurkovich.

    Shot put: Michelle Carter, Jill Camarena-Williams, Sarah Stevens-Walker.

    Pole vault: Kylie Hutson, Jenn Suhr, Lacy Janson.

    High jump: Brigetta Barrett, Inika McPherson.

    Triple jump: Amanda Smock.

    Long jump: Brittney Reese*, Janay DeLoach, Funmi Jimoh, Tori Polk.

    Heptathlon: Sharon Day, Hyleas Fountain.

    Marathon: Kathy Newberry, Alissa McKaig, Colleen DeRuck, Tera Moody, Zoila Gomez.

    4x100 relay pool: Jeter, Myers, Barber, LaShaunte’a Moore, Alexandria Anderson, Bianca Knight.

    4x400 relay pool: Richards-Ross, Felix, McCorory, Dunn, Beard, Natasha Hastings.