Okay, now that I've got to get a good look at it, here are my detailed thoughts.
First of all, and this has nothing to do with the picture itself, but I think the photograph of it could be tweaked. It's a bit too dark I think. I always run my pics through a quick edit on paint.net and it's doing wonders sometimes

As I said before, the composition is absolutely great, I cannot see any flaws aside from the unforgivable
death disappearing of Petrie

Now let me start from top to bottom:
Redclaw looks really really gooood here, you nailed the expression, looks like a mix of anger, annoyance and disgust

Littlefoot looks kinda sad (maybe about Petrie's disappearing?

), I like his expression

And, and Ali was certainly a sweet surprise, considering she's my second favourite character after Ducky

The raptors and the gang are small but considering the small size they look really spot on, even little Ducky. In particular, I like Ruby's pose here

Chomper is literally standing on the title which is pretty funny to be honest

After reading your author's (artist's?) note, I can certainly see why you chose that pose and expression for him. All looking really nice (and I see you went with brown in the end for the title, certainly works!

)
As always, your art stuns me, you really have some hidden talents there I believe

Keep it up, now I totally feel more confident about my own attempt which... well, you know how hopeless I am again
