Sequel to this question.
Basically, I've been designing an intelligent avian race based on bats. After reading through some of the answers for the linked question, I've decided that these bats will be a cross between our modern bats (such as the Flying Fox) and Anurognathid pterosaurs. I'm still going to call them 'Bats' just for convenience though.
However, I've been pondering one key aspect to my design: I've been wanting to make these bats with another set of arms.
This is mostly because, as an intelligent race, being capable of fine manipulation is an asset. My bats have thumbs like the Flying Fox and 2-3 non-webbed fingers. However, since many pterosaurs have long metacarpals in proportion to their fingers and thumbs I'm worried that these hands wont be as flexible. Additionally, bat feet don't seem to be as capable of fine manipulation like some bird feet are.
So here's what I've been thinking: What if these bats had a small set of arms that could fold close to the body when flying?
These arms don't just have to be for fine manipulation. Bats can catch small prey with their feet, but appear to be limited because of how their legs move up and down with their wings when they fly. If they had a set of arms that could move independently of the wings, they could probably more easily catch prey without throwing off the flight.
Or, they might be able to. My main questions regarding this setup are:
- What anatomical changes need to be made for this setup to work?
- Could a bat like this even fly?
Edit: If it helps for answering, these bats would be among many species that evolved from a hexapodal ancestor. The world they come from is separate from our own world, so don't let the fact that we don't have hexapodal mammals on Earth limit you!