The Pokémon universe is populated with fictional creatures, but what some fans may not be aware of is the evidence that real-world animals exist in the world. There are mentions of animals in the main series games, spin-off games, anime, manga, and even the Trading Card Game. These occurrences are too common to brush off as coincidences. Aside from the mentions of real-world animals, there is actual evidence to be found in the official artwork. The image for the Old Amber fossil in Gen I clearly depicts a mosquito visible inside the item, leading to one of the first concrete pieces of evidence that animals are canon in Pokémon.
Pokémon Red and Green were released outside of Japan as Pokémon Red andBluein September of 1998. In the first generation of games, there are three different fossils players can attain, the Helix fossil, Dome fossil, and, of course, the Old Amber. Fossils can be used to revive extinct Pokémon. The Helix fossil contains the Rock/Water Omanyte, players with the Dome fossil obtain the Rock/Water Kabuto, and the Old Amber is used to revive the powerful Rock/Flying-type Aerodactyl.
Related: The Most Underrated Fossil Pokémon
As his name implies, Aerodactyl's design is based on the real-world pterodactyl, not a mosquito. The question as to why this bug is depicted in the Gen 1 artwork for the Old Amber, as seen on Bulbapedia, still remains. Amber is fossilized tree resin and for a mosquito to be found in the item, the bug must have landed on the substance before it hardened. It's entirely possible that mosquitos are not found in the games because they are also extinct and existed when this ancient Pokémon roamed the land. The artwork for the Old Amber has since been changed, but there is other evidence
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