The Carboniferous Expansion

The Carboniferous Expansion was an expansion in the game's history. It started with the Carboniferous Update (or patch 1.5.1). This update was a serious game changer for most of the playerbase because of the two main changes it introduced.

The first is that it introduced abilities that allowed Vertebrate players to join terrestrial servers. Up until this point Arthropods had total control of the land. But all of this changed once the devs gave Vertebrates access to the Amniotes skill tree. The most important thing this led them unlock was the Eggshell ability, which allowed them to move their spawn points on to land. It looked like the meta was going to be rapidly evolving becoming more balanced and diverse. So as one can imagine, most of the community was excited when it came.

However, this hype was quickly overshadowed by the glaring lack of balance across all of the terrestrial servers due to the second change the devs made. What they did was bump up the spawn rates of plants. Although their motive was unknown, some have theorized that they were worried that there wouldn't be enough loot for all of the emerging terrestrial factions. This was obviously a massive oversight on their part. Increasing the plant spawn rate also increases the oxygen level of the overworld. The devs had overlooked the fact that Arthropod players benefited the most from increased atmospheric oxygen. And so, even though the devs were trying to shift the balance of power away from the Arthropods by buffing a new competition, what ended up happening was that Arthropods became far more powerful than the new terrestrial Vertebrates could ever challenge.

The Carboniferous was divided into two main expansions, the Mississippian (Patch 1.5.1.1) and the Pennsylvanian (Patch 1.5.1.2). Many players regard these as the actual expansion rather than the Carboniferous

## Reign of Arthropods

The Health stat of an Arthropod scales directly with the atmospheric oxygen. This is why in the meta of present day, all terrestrial Arthropods are stuck in the lower weight classes with an oxygen level of only around 20%. They're better off sinking their evolution points into other stats and abilities. During the Carboniferous meta the oxygen  level was around 35%, meaning that with only a few points spent on Health, Arthropods could have a ridiculous amount of Health and still have plenty of points to put into other skills like Venom, Armor, and even the coveted Flight ability.

On the down side, the Carboniferous Expansion introduced many nerfs to the previously-flourishing fish guilds, including the termination of the entire placoderm and ostracoderm playerbases. Trilobites and brachiopods also received heavy nerfs, eventually leading to the future dominance of bivalve guild and the total elimination of the trilobite guild with the Permian-Triassic balance patch.

## Notable Builds

These are some of the most notorious of over-stated Arthropods. All of these are S tier by default, since the only competition they had was from other arthropods, though giant amphibians like Protogyrinus could pose a threat if the giant arthropods ventured too close to the freshwater biome.

### Arthropleura

Arthropleura was a Millipede Defense-based tank build. It had armor that was superior to any modern-day Turtle or Armadillo. The armor could defend against the fangs of giant Spiders and the bite of ancient Amphibian jaws. As impressive as this is, it's worth noting that this build was even more OP at the time due to a lack of Intelligence builds, which are the main counter to Defense builds. Arthropleura was a herbivore, which meant it's only real weakness was for the most part, irrelevant.S tier

### Griffinfly

The Griffinfly was a Dragonfly build the size of a Eagle. They had the same unmatched Aerial Mobility that the modern-day Dragonfly players do, but without the glaring lack of Health, Defense, and Power. Because of this, these players had a completely unchallenged dominance over the aerial domain and were a nightmare for the struggling new Reptile and Amphibian players that were trying to break into the terrestrial meta. However, Griffinflies were all-but-defenseless when ambushed from the water by max-level amphibian players,unless the stayed high in the air where the non-frog salamander things couldn't reach them.S tier.

## End

After 60 million years of one of the least diverse metas of all time, the devs dropped the Permian update, also know as patch 1.1.6 or the Great Rain Forest Collapse. This update decreased the plant spawn rate and the oxygen levels in the atmosphere. As a result, the giant Arthropods became unviable. This allowed terrestrial Vertebrates to finally gain a foothold in the meta and eventually led to Reptile builds dominating the meta. Arthropods wouldn't become top-tier again until a few expansions down the line, when Insects unlocked the Eusocial ability.