This article contains information that relates to the non-canon game Pikmin: Ultimate Doom by Wraith.
Duron is the second planet in Pikmin: Ultimate Doom, and, much like Distant Planet, has a mostly Nitrogen/Oxygen atmosphere. The last areas in Pikmin: Ultimate Doom take place on Duron but the very last one, Dark Moon takes place on Krypton, the planet's natural satellite. A variety of animal and plant life can be found on Duron, most of which significantly different from Distant Planet's life. However, there many cases of convergent evolution, where there are organisms much similar to others (specifically, on Distant Planet) that are seemingly unrelated.
There is evidence of ancient civilizations on the planet. In some of the northern tundras there are ruins of temples and significant stone tablets with no inherent reason in creation other than to just "build a tablet". Many details of the planet are skeptical and Captain Olimar's report is widely controversial because all attempts to visit the sector fail.
The northern regions of Duron are covered in tundras. The area between the tundra and equator is all grasslands and forests. Since the three major landmasses are all very thin, much life is able to travel to the sea and still maintain life in the middlelands. On the equator lies rainforests and just due south it becomes very dry and warm, this is due to the Codne Effect, with the atmosphere's jet stream cut off below the equator. The jet stream then diffuses off into the upper atmosphere. This is most likely due to the mountainous regions on all of the land on the southern areas of the equator. Below the equator there is little rainfall, with the exception of certain coasts, archipelagos, and islands.