I’m not a doctor — I don’t even play one on TV — but I know enough about human anatomy to question this claim on Yahoo! Sports:
I didn’t recognize the term dorsal vertebrae because the current term is thoracic vertebrae. The term dorsal vertebrae has been obsolete for a long, long time. (If you want to be nitpicky, all vertebrae are dorsal since the term refers to the back.)
Anyhoo, I guess we shouldn’t expect a sports writer to be concerned about such things, although I would expect an editor to know the difference between a singular and a plural noun. I don’t know much about Latin, but I know enough to recognize that vertebrae is the plural of vertebra.