2018 Reef Safari Nautilus Limited Edition Medallion & Stamp Cover PNC

2018 Reef Safari Nautilus Medallion & Stamp Cover PNCThe nautilus is a mollusc called a cephlapod and is related to the squid and octopus. A 'living fossil', the nautilus has hardly changed in 400 million years.It dominated the ancient seas before the rise of  fishes, and appeared about 265 million years before the first dinosaurs. In prehistoric time, there were about 10,000 different species of the nautilus, but only 11 of these survive today.Nautilus pompilius pompilus, also called the Emperor Nautilus because of its large size, is the most widely distributed and best known of nautilus species. It can be found in the Great Barrier Reef as well as in the Andaman Sea, Fiji and southern Japan. the largest of all nautilus species, its shell diameter can reach 25 centimeters. Nautilus species can live up to 20 years.The Nautilus is a scavenger and predator, feeding mainly on small crustaceans. The numerous (around 90) tentacles of the nautilus are equipped with sensory cells that can locate the bodies of the dead animals on which it feeds. Grooves and ridges on the tentacles are used to grip prey and deliver food to a crushing, parrot-like beak, before being stored in a stomach-like organ called a crop.The striped shell is light on the bottom and dark on top, a camouflage that helps the animal avoid predators sch as octopuses, sharks, triggerfish and sea turtles.The pearly, decorative shell is prized by collectors. This has resulted in t he decline of some nautilus populations and a subsequent ban in export in some countries.This year has been declared the International Year of the Reef.The Nautilus shaped medallion is enclosed in a full colour card inside a commemorative Australia Post C5 sized envelope, includes $1 Commemorative Stamp featuring the Nautilus - Great Barrier Reef.Postmarked First Day of Issue 1 August 2018, Cairns QLD 4870.Denomination :       MedallionFinish :                   Silver FinishMetal :                   Zinc AlloyWeight :                 45 gmsDiameter :              68.00 mmMintage :                3,500Authenticity :          Australia Post Seal of Authenticity