Otter-like fantasy race

It's a concept my brother and i came up with a while ago for a project he's working on. Basically those are sentient creatures evolved from otters in post-apocalyptic earth millions of years into the future. They live in small groups on the back of giant bears who they share a symbiotic relationship with and travel all the time.
I just thought the concept art looked nice enough to share i'll probably keep posting more concept art in the future