Adaptall mount was an innovation from Tamron. But it is only available in their old manual focus film lenses. The idea is that you can buy a 90mm Tamron lens with a Nikon Adaptall mount but if later you want to use the lens on a Canon body you just need to buy the Canon Adaptall mount and change the Nikon mount. Therefore you don't have to buy a new lens. One lens but many mounts.
In the early 80s, when all SLR are manual focus, Tamron launched a range of lenses, with separate lens mounts (the Adaptall2), the user need to buy a separate lens mount, eg if u use Nikon buy Nikon mount, if later u change to Canon u keep the lens and just buy a Canon mount, etc.
Now, if u have a old Tamron lens, u must also need a Adaptall2 mount, there should be marking on the mount to say what brand it is for.
Some are coded. You see markings on the mount like N/AI which means Nikon AIS mount. Experience users are able to tell one mount to another as they are very different. Mount with a pair of prongs is uniquely Nikon F.