NEW YORK — A startling new report asserts that the first known Americans arrived much, much earlier than scientists thought — more than 100,000 years ago __ and maybe they were Neanderthals. If true, the finding would far surpass the widely accepted date of about 15,000 years ago. Researchers say a site in Southern California shows evidence of humanlike behavior from about 130,000 years ago, when bones and teeth of an elephantlike mastodon were evidently smashed with rocks. The earlier date means the bone-smashers were not necessarily members of our own species, Homo sapiens. The researchers speculate that these early...