I understand the surname Mayr and variants, Maier, Mayer, etc., is quite common. There could well be more than one such Michael born at this place at about that time.
A Google search >> "Michael Mayr" Germany 1690 << returns what seem some genealogically signicant items. I listed a couple that may be of interest below, but you may want to conduct the search yourself and discover more.
1. "Mayr/Maier from Oberalfingen," on Baden-Worttemberg mailing list, 2001, _RootsWeb.com_.
A Susan Hewett researching the descendants of "Michael Mayr" from Oberalfingen. Indicates a wife's name is known. Two responses. See especially comment by Lyle G. Hartman for resource and location details including, "Oberalfingen was a Non-Gemeinde parish. The parent parish, according to Charles Hall's "Atlantic Bridge to Germany", Vol. 1, was Hofen, Landkreis Aale." http://archiver.rootsweb.ancestry.com/th/read/BADEN-WURTTEMBERG/2001-04/0986468011
2. "Mining in Oberalfingen," posting/thread on message board for Baden-Wuerttemberg, 2001-2004, _Ancestry.com_
Started by "Shewett" (perhaps the same as above?) who opens with, "I am searching for the Maier family from Oberalfingen. There are numberous members from that area." http://boards.ancestry.com/thread.aspx?mv=tree&m=9522&p=localities.ceeurope.germany.baden.general
See especially post by Karl Ilg, 2004, that opens, "I am originally comming from Hofen." Karl also writes, "The Maier, Mayr, Mayer is a very common family name in our region. It is as common as Mueller or Schmid = smith...."
Apparently Karl has Maiers in his family tree.
Hope this helps.