Commemorative cancel depicting Quetzalcoatlus northropi used on a Certified Mail cover is unusual as commemorative cancels are normally used on philatelic mail. This certified mail (75 cents) 1st class (22 cents) cover from Detroit, MI (10 Oct 1986) to Army Post Office (APO) New York 09333 (Sandhofen, Germany) was back-stamped as received on 22 Dec 1986 at APO New York 09102 (Heidelberg, Germany). Evidently, the mail was ‘really slow’ when carried by pterosaur!!!
Quetzalcoatlus commemorative cancel
The Mesozoic Times 