Crests - rank insignia - insignia

Good Afternoon

I am trying to track down the crest / rank insignia for a Decanus or Contubernium

A ten man tent commander (section commander in the present day commonwealth military) I believe - and I am only learning at this phase - is called a Decanus. 

I once held the rank of a section commander - ten man commander - and my name is Dean. 

I had once found a crest (I will see if I can dig it up) that was reportedly that of a Decanus (Legionnaire-type body with armour, roosters head, snake for a leg, holding I believe something like a Trident on a circle). 

the significance of my name and Mil service has not escaped me 

Any help would be greatly appreciated