Pachypleurosaurus is a genus of pachypleurosaurian that lived during the Triassic Period. It was a basal sauropterygian, and had a long neck. The type species is P. edwardsi. Pachypleurosaurus is now considered a Nomen Dubium, likely synonymous with Neusticosaurus. It can grow 18 inches long, it was one of the smallest nothrosaurs.
Pachypleurosaurus has never appeared or been mentioned in any Jurassic Park films or books, it has however appeared in Jurassic Park III: Park Builder.