Tanystropheus

Tanystropheus was a genus of the Prolacertiformes order, not the Dinosaur order. Tanystropheus was an aquatic or semi-aquatic reptile which was most likely piscivorous (or 'fish-eating'). It lived during the Triassic period in Europe and the Middle East. It had an extremely elongated neck, which measured 3 meters (10 ft) long - longer than its body and tail combined. Its skull had a long, narrow snout sporting sharp interlocking teeth. Skin impressions of Tanystropheus, showing that it was covered in semi-rectangular, non-overlapping pattern of scales.

More real-life information: Tanystropheus at Wikipedia.

Jurassic Park Series
Tanystropheus never appears in the novels or movies.

Jurassic Park Toys

 * A doll of Tanystropheus appeared in Kenner's toyline Jurassic Park Series 2. It had a flexible neck to grab a human doll ("constrictor neck attack").