The currency of Mongolia since 1925 has been the tögrög, which currently circulates mostly as banknotes due to the low value of earlier coins and the reluctance of the government to issue large denomination coins; however, the government has authorised many non-circulating legal tender (NCLT) coins to be issued for collector's purposes.
Collector coins are dedicated to historical or general popular culture themes and are often not related to the country itself. Many of them are in internationally popular sizes, such as the half gram of gold mini-coin format.
This coin is part of the second release in the Evolution of Life collection, and features the Trilobite.
The series features select fossils from various geologic periods, in one large silver and one small gold format. Each silver issue shows a rose-gold plated fossil, typical of the respective geological period, partially excavated on an antique finish rock matrix background. The gold coin motifs mirror those of the larger silver coins, if in reduced complexity and design. Instead of a partially excavated fossil on a rock matrix background, the little coins show the isolated fossil on a proof surface with English name, year of issue and series name. Despite their small size, their minting is incredibly rich in detail.
The mint says about this coin:
A coin 470 million years in the making... The hugely popular first issue of the new Evolution of Life series "Ammonite" raised high expectations and anticipation for its successor. The 2016 coin now presents the Ordovician period with a stunning, partially excavated trilobite, which is based on a real, 470-million-year-old fossil found near St. Petersburg, Russia. The original measures nearly 8 centimetres and belongs to the species Cheirurus ingricus. As expected of the series, the trilobite is minted in impressive relief with a brilliant red-gold finish. | 
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