Welcome, this is a guide key to the fauna that you will be encountering in Jurassic Park.
Pterosauria - flying reptiles, not dinosaurs, come from Ornithodiran (Bird-necked) Archesaurs (ruling reptiles)
Dinosauria - true dinosaurs, come from Ornithodiran Archesaurs
Saurischia - "lizard-hipped" dinosaur
Theropod - Bipedal carnivores branching from Saurischia
Ceratosaur - earlier forming theropods with flexible tails and 3 or more fingers
Tetanurae - later forming theropods with interlocked stiff tail vertebrae with 3 or less fingers
Sauropodomorpha - quadrupedal herbivores branching from Saurischia
Ornithischia - "bird-hipped" dinosaurs
most small theropods of the cretaceous were covered in feathers
birds did come from dinosaurs - see above
larger theropods probably not covered in feathers during adult stage, but probably covered in feathers as young
Ornithischia is misleading- these dinosaurs did not evolve into birds
birds actually have reptile hips in embryo, but hip positioning changes during gestation to "bird-hip"
more to come with additional species...
- Tommy Q.