JEFFERSON CITY, Mo. -- Although somewhat slow and shy, the box turtle and crayfish have risen to the top of their classifications as the newest official state symbols.

Legislation signed into law Thursday by Gov. Matt Blunt designates the three-toed box turtle as the official reptile of Missouri and makes the crayfish, also known as the crawfish or crawdad, the official state invertebrate.

Both animals were championed by school children, who have originated many of the recent additions to the state's list of symbols.

About 20 sixth-grade students from Reeds Spring, who were fifth-graders when they adopted the crayfish as part of a class project, came to the Capitol to stand behind Blunt as he signed their bill into law.

Rep. Jim Viebrock, R-Republic, explained that the box turtle bill had been advocated by sixth- and seventh-grade science students in the Southwest School District in Washburn, although those children weren't present Thursday.

Missouri already had 20 official symbols heading into the 2007 legislative session, including standard items such as the state flag and less common symbols such as the official state dinosaur (a type of hadrosaur known scientifically as the hypsibeme missouriense).

Besides the turtle and crayfish, Blunt already has signed a bill making big bluestem the official state grass. Still awaiting the governor's signature is a bill declaring the bobwhite quail the official state game bird.

Blunt said he assumes there will be more, because children get both a science and government lesson when they research and advocate for their favorite plants and animals.

"It's amazing what they come up with up," Blunt said. "I'm sure we'll be stunned by their innovation as we name yet another state symbol next year."