It could be the long-lost ancestor of the dinosaurs from Jurassic Park. A fossil discovered in the UK is thought to be the oldest Jurassic dinosaur ever found and is one of the most complete specimens from the time period.

The well-preserved remains of a juvenile dinosaur were found at Lavernock Point near Cardiff, Wales, a location that exposes rocks spanning from the late Triassic to the early Jurassic.

The fossil came from rocks that lie right in between these two eras, but subsequent analysis showed the specimen was from the early Jurassic.

“Only a few handfuls of specimens worldwide come from this time and most of them are only fragments,” says Steven Vidovic from the University of Portsmouth in the UK, a member of the team that investigated the fossil.

The early Jurassic is a critical time in the evolutionary history of dinosaurs. An extinction event in the late Triassic wiped out many plants and animals, but not dinosaurs.

The species that crossed over into the Jurassic are thought to hold clues as to how they diversified into the many species that existed in the middle Jurassic, some of which are the ancestors of birds.