Okay, so in he name of science and boredom, I have counted all the dinosaurs that appear in the original movie, a sort of census.  I think you'll be interested in my findings.
FIRST MOVIE
First of all pterosaurs are the most common type of creature in the movie, including 12 pteranadons, 8 peteinosaurus, 1 dimorphodon, and finally, sordes counting the group at littlefoots hatching and the swarm at the beginning of the movie they number in at 168 individuals... And the fact that they don't show up ever again, in the sequels or otherwise is terrifying.
Moving on to the stars of the movie, we have 18 Apatosaurus, 15 saurolophus, and 34 triceratops- 27 of which are present in the valley at the end of the movie. Spike's the only stegosaurus.
There are 20 archelon, 6 struthiomimus, 3 pachycephalosaurus, 1 Rooter, 6 lonsquama, 1 colossochelys, 3 lesothosaurus, 2 hylonomus, and 4 edaphosaurus.
There are three types of sharp teeth in this film and 1 of each, tyrannosaurus, dimetrodon, and metriorhynchus.
There are seven other species that only make one appearance those creatures are: erops, lystromysaurus, steropodon, diphyontosaurus, cimolestes, proganochelys, and platyhystinx.

SECOND MOVIE
 I think I should re-tally the creatures of the first movie first. So in a addition  to our main 3 Apatosaurus, 7  others made it into the great valley. The trike herd, if you include Ceara and Toppsy, has dwindled to about 19. There are 2 adult stegosaurs and 14 new pteranodon- if you count eggs. The saurolophus herd 19 members counting the 7 adults,  ducky, and her 11 sisters (6 from the first brood, 5 from this one).
Finally, 2 struthiomimus made I into the valley,  but are likely dead by the end of the movie.
 4 tyrannosaurus appear in this movie, this may explain the decrease in trikes .
Other animals such as the maiasaura and her clutch of 6,1 kuchneosuchus, 1 brachiosaurus, 1 plateosurus, 1 europlephalus, 1 scutosaurus, and a moschops, have such low numbers its unsurprising they don't appear again.





Do with this information what you want , but know that I'm going to update this list of every movie.

great job  

At the time, there weren't any sequels intended, so these eggstealers are simply random background characters. Ozzy and Strut were created a few years after the movie was released.

Gosh, well good job having that determination!

Okay, so in he name of science and boredom, I have counted all the dinosaurs that appear in the original movie, a sort of census.  I think you'll be interested in my findings.
FIRST MOVIE
First of all pterosaurs are the most common type of creature in the movie, including 12 pteranadons, 8 peteinosaurus, 1 dimorphodon, and finally, sordes counting the group at littlefoots hatching and the swarm at the beginning of the movie they number in at 168 individuals... And the fact that they don't show up ever again, in the sequels or otherwise is terrifying.
Moving on to the stars of the movie, we have 18 Apatosaurus, 15 saurolophus, and 34 triceratops- 27 of which are present in the valley at the end of the movie. Spike's the only stegosaurus.
There are 20 archelon, 6 struthiomimus, 3 pachycephalosaurus, 1 Rooter, 6 lonsquama, 1 colossochelys, 3 lesothosaurus, 2 hylonomus, and 4 edaphosaurus.
There are three types of sharp teeth in this film and 1 of each, tyrannosaurus, dimetrodon, and metriorhynchus.
There are seven other species that only make one appearance those creatures are: erops, lystromysaurus, steropodon, diphyontosaurus, cimolestes, proganochelys, and platyhystinx.

SECOND MOVIE
 I think I should re-tally the creatures of the first movie first. So in a addition  to our main 3 Apatosaurus, 7  others made it into the great valley. The trike herd, if you include Ceara and Toppsy, has dwindled to about 19. There are 2 adult stegosaurs and 14 new pteranodon- if you count eggs. The saurolophus herd 19 members counting the 7 adults,  ducky, and her 11 sisters (6 from the first brood, 5 from this one).
Finally, 2 struthiomimus made I into the valley,  but are likely dead by the end of the movie.
 4 tyrannosaurus appear in this movie, this may explain the decrease in trikes .
Other animals such as the maiasaura and her clutch of 6,1 kuchneosuchus, 1 brachiosaurus, 1 plateosurus, 1 europlephalus, 1 scutosaurus, and a moschops, have such low numbers its unsurprising they don't appear again.





Do with this information what you want , but know that I'm going to update this list of every movie.

I am aware this is old, but I feel like bringing up that there is a Velociraptor, one Struthiomimus (The other egg stealers in the 1st movie are Ornithomimus) , two Seismosaurus, and one Torosaurus, as well as two Parasaurolophuses.

Just felt like bringing that up.