My question is how/why does my creature evolve into having arms when it has none?
Context: I am currently creating a evolutionary tree for the first animals of my planet. My planet is the size of earth with a similar climate to earth in the Carboniferous era.
It’s mostly covered in swamps, jungles, savanna, and what I like to call mushroom fields(fields of moss and Prototaxites) It’s rather warm.
One of the first creatures is a two legged, fast, long necked, type of reptile. Its a herbivore and it’s main competition is its cousin which is like it but more heavyset.
It’s main source of food is a small parasitic fern that is found high on trees.
I think it might need arms to climb the trees or defend itself against predators but I need help in defining its future as hopefully the first sentient race of the planet.