PHOENIX - Human remains found by two children playing in the desert hills in northwestern Arizona last year are believed to be that of an American Indian man who lived about 1,800 years ago, a local anthropologist said on Wednesday.Giving an approximate date to the largely complete skeletal remains, which were recovered in an area southeast of Colorado City, was only accomplished recently, said Amy Kelly-McLaughlin, the anthropologist who examined them. She specializes in vertebrate forensic taphonomy, the study of ancient remains.But the Flagstaff, Arizona-based Kelly-McLaughlin, who was hired by the Mohave County Medical Examiner's Office to find out more about the remains, said the results validate her initial impression."The minute I opened the box with the bones I knew it was prehistoric," she said in a phone interview. "There was just no doubt in my mind that it is."She said the remains, which belonged to a man whose age at death was unclear, were well-preserved and represented about 85 percent of the body. They displayed classic prehistoric signs that included deeply stained bones from the sediment in the ground and severely decayed teeth.