DS had similar traits and a few others that had me thinking ASD when he was younger but now that he's 8 he doesn't fit that at all. He is still introverted and will never go up and play with kids he doesn't know. He still keeps to himself at the park or if he's thrown in with a group he doesn't know well. However when he's around kids he's known for years he is fine. He is definitely better 1 on 1 rather than in a group (and as an introvert myself I totally get that). We have deliberately tried a few team sports since I know this helped me as a kid. It gave me kids that loved something and gave us something in common to talk about. It was easier than completely unstructured play for me.
His dinosaur obsession has lasted for years (and he still will read more if we can find stuff that he doesn't already know). It got easier when he started to read and I wasn't his main source of info/entertainment. Now my main role is to find cool library books to pile beside his bed.
