St. Helena & Ascension 5-PENCE (KM22)

Jonathan is an Aldabra giant tortoise (Aldabrachelys gigantea) from the Seychelles islands. He arrived in St. Helena in 1882 apparently at the age of 50. If Jonathan really did hatch in 1832, that would make him 184 years old as of 2016, and the oldest living mammal on earth. (Another Aldabra giant tortoise -- who lived in India -- died in 2006 at the unconfirmed age of 255.)

Most Aldabra tortoises live on the islands of the Aldabra Atoll in Seychelles. Here, 100,000 of these incredible reptiles have caused a unique ecosystem -- called "tortoise turf" -- to co-evolve. Tortoise turf features over 20 unique species of grasses and herbs, many with their seeds very close to the ground to avoid the tortoises' munching jaws.