If it had four legs and ate plants, it was a sauropod. If it was medium to small sized, had two legs, and was possibly an omnivore, it would be a Therizinosaur or Ornithomimid.
The dinosaur with a long snout like an elephant is called a Brachiosaurus. It was a herbivorous sauropod dinosaur known for its long neck, small head, and nostrils located on the top of its head, giving it a resemblance to an elephant.
Argentinosaurus was the biggest hervivorous dinosaur that has a long neck.
Amargasaurus.
There were a number of long-necked dinosaurs. One was the brontosaurus.
Diplodocus.
Plesiosaur
A long neck dinosaur that eats plants
grass and leaves
This depends on which long-necked dinosaur you are talking about. Heights varied between species.
Janenschia is a dinosaur. It was a huge dinosaur with a long neck and tail.
it has a long neck
mamenchasaurus