Environmental Changes
As the time goes volcanic activity leads to the start of global warming. The global surface temperature continues to increase which in turn causes global warming to increase. At 6,000,000 years ago Darkland collides with Kalorme. Darkland is desert so this causes Kalorme to become a desert. Then at present day Orcarnia collides with Kalorme. Kalorme is now called “Greater Kalorme” and is mostly desert land.
The grassland biome evolved into a desert biome as other lands collided with it. Since global warming started the heat on Greater Kalorme is now hotter than ever. The grass from the grasslands is no longer here and the rattlesnakes cannot avoid the heat as easy anymore. There is mostly flat ground with a couple of heat-surviving plants like cactus. It barely rains but this is not a problem for these plants since they have adapted to retaining water.