This is a speculative evolution project about silly alien lifeforms from an ancient Mars with liquid water. It's probably going to perpetually be a work in progress so please excuse unfinished parts, thank you.

The Basics of Old Mars

Old Mars is relatively Earth-like in many respects

• A day is about 24 and a half hours long. Years are about 672 days long (which is about 687 Earth days) and it has seasons that are very similar (albeit longer) due to the tilt of the axis

• The atmosphere is mostly O2, N2, and CO2 (as well as other trace elements) The high amount of CO2 comes from the large amounts of volcanic activity and is vital to regulating the temperature of the surface. Free O2 can be found as simple photosynthetic organisms, much like cyanobacteria on Earth, became well established early in its history

However, there are still differences 

• With a weaker magnetosphere the atmosphere is lost over time. The plentiful volcanoes help replenish it. (Sadly, this cannot go on forever)

• There is little tectonic activity on Mars, the crust is very thick and broken into only 2 plates. This leads to very different bio-geography than we're used to

• The surface gravity is only about a third of Earth's. People tend to conceptualize Mars as similar in size to earth but look at that little thing

The Timeline*

Here is a timeline of Mars' natural history compared alongside Earth. (WIP: I'm figuring out a way to make this chart pretty)

*There are estimates for how long Mars would've been habitable in real life and they range from around 600 million to 1.1 billion years. Events on Earth that led to the development of animals either had an extremely low chance to happen or just straight up couldn't have happened on Mars, so this project diverges away from reality pretty quickly