Study Finds Stegosaurus Dinosaurs Moved in Herds

The El Castellar site is the most important in the world in terms of scientific significance and the number of traces of these herbivores.

A publication in the journal Scientific Reports analyses the largest collected sample of marks of this type and conducts an in-depth 3D study of the burns.

A new study by the Dinopolis Foundation has allowed us to deepen our knowledge of the ichnites (fossil footprints) of stegosaurs, a group of herbivorous dinosaurs that walked on quadrupedal legs and were characterized by plates and/or spikes located from the neck to the end of the queue. The study analyzed footprints attributed to this type of dinosaur, located in eight sites dating back approximately 150 to 145 million years in the province of Teruel, which constitute the largest “database” of this type of footprints in the world. The deposits are located in the municipalities of Ababuj, Aguilar del Alfambra, El Castellar, Galve, La Puebla Valverde and Formiche Alto.

The studied ichnites are known by the scientific name Deltapodus due to the triangular shape (inverted delta) characteristic of the footprints and kidney-shaped hands. 2010 was a major turning point in the study of this type of footprints, as the Foundation’s paleontologists discovered a track (several successive tracks of the same individual) 23 meters long at the El Castellar site. This track allowed the identification of a new type of footprint called Deltapodus ibericus.

In the new study, 57 of the best-preserved ichnites from the El Castellar site and 29 from seven other sites were analyzed individually, yielding a total of 86 tracks, in order to analyze how they differ from those of other tetrapod dinosaurs, as well as to delve deeper into the team’s previous hypotheses regarding the possible gregarious behavior of these dinosaurs. In this regard, Diego Castanera, the first author of the publication, states that “gregarious behavior is well documented in other dinosaur groups; however, in stegosaurs, this has only been suggested at two sites in Teruel, El Castellar and Aguilar del Alfambre. In this new study, we were able to confirm previous hypotheses that the stegosaurs that left the tracks walked in the same direction and at the same walking speed. These data therefore support this type of behavior. During the investigation, 3D modeling of the sites was essential to identify the tracks, as it is very difficult to trace dinosaur steps at sites with hundreds of tracks, such as El Castellar, where the number is estimated at around 800. This study will undoubtedly help to identify tracks of this type in other parts of the world and perhaps to identify other cases of herding.”

Louis Mampel, co-author of the publication, emphasizes that “the study used laser scanning and photogrammetry techniques, which not only allowed us to collect new scientific data from some already known sites, but also allowed us to preserve the paleontological heritage through 3D models. “We had previously noticed great differences in the shape of this type of ichnite, but until now it had not been studied in detail whether they were all the same type of trace or whether they were different.”

Alberto Cobos, Managing Director of the Dinopolis Foundation and co-author of the publication, points out that “since the Foundation began its research in 2002 at the El Castellar site, we have had uncertainty about the dinosaurs that left some of the dozens of tracks present. In 2010, we attributed some of them to stegosaur ancestors and described Deltapodus ibericus. Now, by relating the variations in the shape of the ichnites to the state of the sediment, the anatomy and position of the legs and arms, or the size of the tracks, we conclude that all the ichnites studied at this site and at seven others in different municipalities of Teruel can also be attributed to Deltapodus ibericus. We can now firmly state that the El Castellar site is the most important in the world in terms of scientific significance and the number of stegosaur tracks.”

The study was published in the prestigious journal Scientific Reports of the Nature group and is called “The complexity of tracking stegosaurs and their herd behavior.” The authors are paleontologists from the Teruel-Dinopolis Paleontological Complex Foundation Diego Castanera, Luis Mampel and Alberto Cobos. DOI: 10.1038/s41598-024-64298-9

The publication is part of a study by the FOCONTUR research group, financed by the Department of Education, Science and Universities of the Government of Aragon. It is also included in the studies of the Paleontology Department of Teruel, financed by the Ministry of Science, Innovation and Universities of the Government of Spain.