Mine too, head spinning that is. This is from Tamrons Lens Brochure:
Note: Because Nikon mounts may/may not have built-in AF motors, please refer to the table above for the model in question.
AF motor is built-in for Nikon II models. Please refer to the bottom left table for "[Compatibility of Di series with built-in AF motor for Nikon with Nikon cameras]". Aperture ring is not equipped.
AF motor is not built-in on Nikon model. When Nikon models are used with D40, D40X, D60, D3000, D3100, D3200, D3300, D5000, D5100, D5200 and D5300, the lenses function only in the manual focus mode.
*The lens for Nikon/Sony is “D“ compatible.