In my verse there is one planet which is very warm and typically dry, deserts of black sands or large stone plateaus, outside of the area around rivers and on the lush sides of mountains. This also makes it so that water is less available than it is on Earth. It has very high levels of oxygen, has gravity of around 0.85x that of Earth, and it has low levels of iron but high levels of cobalt, so they evolved with cobalglobin blood. This is allowed to work through high temperatures and high levels of oxygen.
I have found that the humanoid species would evolve to have dark skin, be tall and thin, have amber-coloured blood from the cobalglobin, and likely have epicanthic folds to defend against the dry sands and detritus. I know what kinds of plants would develop, but in what ways can I expect the animals to evolve in this environment?
Low gravity and high oxygen would lead to a degree of giantism. But that is about all I can find.
Plants
The Plants are largely succulents, but also tend to have "Shells" of a sort (forgot the scientific term) around their fruits and seeds, they also tend to have needle shaped leaves and such. Typically evolving to develop either Crassulacean Acid Metabolism or C4 Carbon Fixation.
In the more lush areas they tend to have trees with red leaves, they have the same protection around their fruits. And tend to also have various needles around it like that of a Dendrocnide moroides.
Plants in general, like the animals, evolve to deal with the large sandstorms that plague the planet.
Conclusion
So, given all of this, what kinds of evolution can we expect animals to develop in this type of environment? If this is too open ended please give me tips as to how to specify this downward to a more focused question.