U.S. Sen. John Cornyn, R-Texas, and U.S. Rep. John Carter, R-Round Rock, sent a letter June 28 to the U.S. Fish and Wildlife Service requesting a six-month extension for the proposed listing of four salamander species in Central Texas as endangered or threatened, according to a news release.

The letter said, "We have been working closely with the Williamson County Conservation Foundation and other stakeholders on the proposed listing, and we believe that there is significant disagreement regarding the sufficiency and accuracy of the scientific information that the service is using to make a listing determination."

The possible decision to add the Jollyville Plateau, Georgetown, Austin Blind and Salado salamanders to the federal endangered species list has drawn opposition from local residents and leaders because they believe the listings could impede economic development.

The final listing decision is currently set for Aug. 22.