I did this party when the show had only been out for about a year. they were just coming out with the first dinosaur train figures the week of the party. So keeping that in mind this is what we came up with.
The invites were made to look like the train tickets off the show. On the back we put: come have a train-tastic time at (child's name)'s birthday party. All aboard the Dinosaur train at (place of party). Departure is (time and date) come travel through the time tunnel for a dino-mite of a party.
As the kids arrived they were able to color dinosaur train pictures. They are available on PBSkids.org. they received conductor hats to match Mr. conductor's hat on the show.
We had three activities/ games for the kids. They played toss the lava rock into the volcano (we used tin foil for rocks and a trash can and black garbage sack to make a volcano.) they then played hatch the dino (we put small dinosaurs in black balloons and blew them up. the kids had to step or sit on them to "hatch" pop the balloons). lastly we had them dig for dino-bones. (we bought skeleton dinos from Oriential trading, but i have sense seen them at the dollar store. we put out a tarp and put dirt over the dinosaurs (you could use sawdust also) we then gave the kids paint brushes to dig for the dinosaurs.
We then had cake and ice-cream and opened presents. My sister made the cake.
In their goodie bag they got a wooden train whistle, dinosaur fruit snacks, dinosaur suckers, magnifying glasses, notebooks. and they got to keep the dinos they hatched and the ones they dug up, and the brushes they used to dig with.
Things we liked, but cut out : I was planning on making fossils with play-dough and plaster of Paris, but I couldn't get it to work well on the trial run. also I was going to make a balloon arch as a time tunnel, but after the party a few days earlier with the wind I decided not too. I was also going to make large paper mache dino eggs for the goodie bags.