Looks like the separatists have been separated from a couple of letters on the Yahoo! front page:
It’s a national holiday in the U.S., so maybe the people writing for yahoo.com aren’t the usual employees. Maybe they’re not even English-language speakers (or writers). And they’re probably unfamiliar with words derived from Latin. So, I’ll be charitable with this egregious mistake:
How the heck did the writer get the idea that a single bone in the spine was a vertebrae? Huh? Tell me that. A single bone is a vertebra; multiple bones are vertebrae (or vertebras).