Palaeontologists in Spain have discovered the first confirmed Diplodocus fossils outside of North America, marking the first-ever discovery outside the area. For 150 years, every confirmed bone of the animal came from one place, the Morrison Formation of western US. But recently, Sergio Sanchez Fenollosa and his colleagues found the same anatomical signature in a set of tail vertebrae found in Teruel, Spain.The roughly 150-million-year-old remains turned out to be the first confirmed Diplodocus fossils ever found outside North America, the team reported in the Journal of Vertebrate Palaeontology. During the Late Jurassic, falling sea levels may have exposed land that dinosaurs could walk across between the continents. “With each new result, the picture became clearer: we were looking at a Diplodocus,” Sánchez Fenollosa, the study’s lead author, said in a press release.
Identifying the first Diplodocus fossils
The first five vertebrae turned up at La Tejeria back in 2008. It wasn’t until excavations in 2014 and 2015 that the team recovered nine more, along with several chevrons, the bones attached beneath the tail vertebrae. Some of the vertebrae were still connected in the order they’d been in while the animal was alive. The whole find covered roughly 108 square feet (10 square meters).According to Alberto Cobos, one of the study’s co-authors, the animal was about 82 feet long. But even that partial tail is among Europe’s most complete finds from the dinosaur’s wider family. Earlier finds from this family in the region included a tooth and scraps of hip and tail bone.Sánchez Fenollosa, Cobos, and co-author Josué García Cobeña measured the bones by hand with callipers or a tape measure and compared them with published descriptions of other long-necked, plant-eating sauropods. The vertebrae had deep grooves running underneath and no ridges along the sides, while the chevrons were forked.The excellent preservation of the specimen allowed the researchers to recognise several anatomical traits associated with Diplodocus, including:
- Large pneumatic cavities inside the vertebrae
- Deep longitudinal grooves along the underside of the tail bones
- Distinctive forked chevron bones with unique medial fossae
- Elongated vertebral centra without lateral ridges
The team recognised that combination in Diplodocus and checked the identification with computer analyses of the animals’ relationships. The results shuffled other parts of the family tree around, but every version placed the Spanish dinosaur on the Diplodocus branch.
From North America to Spain
Diplodocus now joins Allosaurus and Stegosaurus among dinosaurs from the Jurassic rocks on both sides of the Atlantic. It ranks among the most recognisable dinosaurs ever discovered. It is known for its enormous length (up to 25 meters), long whip-like tail, and relatively small head.Since Diplodocus was first discovered in the United States in 1878, casts of its skeleton have appeared in major natural history museums around the world, particularly during the early 20th century. Those displays helped turn Diplodocus into an international symbol of palaeontology and one of the most familiar dinosaurs in popular culture.At the time these animals lived, the ocean was still opening between the continents. As sea levels fell, stretches of land may have appeared between what’s now Newfoundland and the Iberian Peninsula, home to modern Spain and Portugal. Those temporary routes could have offered animals a way to wander from one continent to the other. However, it still remains unknown to the researchers exactly when Diplodocus crossed between them or which route it took.The team can identify the animal as Diplodocus, but the tail doesn’t preserve enough detail to pin down its species. In their analyses, the Spanish animal came out closest to the North American species Diplodocus hallorum. Finding a more complete skeleton in Europe could help them work out just how closely the two were related.The sediments surrounding the bones were deposited on a coastal plain shaped by rivers. Other enormous plant eaters, including Turiasaurus and Losillasaurus, also lived in what is now Teruel, Cobos notes in the Dinópolis Foundation’s press release. These dinosaurs belonged to a different branch of the sauropod family.The original tail bones are now on display at Dinópolis in Teruel, while visitors in El Castellar can see replicas of the bones unearthed nearby.