This article suggests that the boar as a military standard is the totem animal of Ceres. This seems completely counter-intuitive from a numismatic standpoint. Whenever the Boar is associated with a deity on the coinage that deity is Hercules, A MUCH BETTER GOD to follow into battle than Ceres.
(I also don’t believe the a connection between the manheaded bull and the minotaur.)
My previous post on Military Standards.
A previous post about the denarius with the boar and Hercules.
Liv Mariah Yarrow 
[…] me wondering if I was too quick to think it was non-sense that the pre-Marian standards could have included a female boar, and thus been associated with […]
[…] We should also remember that the boar was a legionary standard used by the Romans in the Republic (early post on this). […]