That’s trouble for the Dominican Republic’s Marileidy Paulino, the reigning Olympic champion in the women’s 400 meters, and Salwa Eid Naser of Bahrain, the Olympic silver medalist.

McLaughlin-Levrone also has two Olympic gold medals in the women's 4x400 relay. Jacory Patterson won the men's 400 in 44.16 seconds to earn a spot on his first outdoor world-championships team.

Now, she is heading to Houston, Texas to participate in the Junior Olympics and run in the 400-meter sprint. "I'm excited," Thomas said. "I think I am going to do pretty well.

McLaughlin-Levrone also has two Olympic gold medals in the women's 4x400 relay. Jacory Patterson won the men's 400 in 44.16 seconds to earn a spot on his first outdoor world-championships team.