look at some of the old movies about dinos like "lost valley", they where always based in the time frame/tecknolagy level steampunk is based.

may build some one tring to catch him with some tecknlagy or riding behind him on somesort of devie.

or

there is a game that is very steampunk like on the pc called

"paraworld"

(warcraft 3 like game) that has a mix of dinos and tecknolagy mixed.

its set in 1927

its about 6 months old. look it up or grab a copy (only cost me £8). might help you out

cgtalk did a 3 part interveiw about the making of the opening - thats how i heard of it.