Science Spain , Burgos, Thursday, May 09 of 2013, 17:41

Found the oldest terrestrial fossil lizard of Varanoidea family

A 125 million-year species, called Arcanosaurus ibericus was found in Salas de los Infantes dinosaur site (Spain)

José Pichel Andrés/DICYT The Sala de los Infantes dinosaur site houses 125 million-year varanoid lizards (its best known species is the Komodo dragon). An international research team has published, in Cretaceous Research, a study describing a new species in this family, specifically, the oldest terrestrial specimen of giant lizards from the remains preserved in the Museo de los Dinosaurios de Sala de los Infantes (Dinosaurs of Sala de los Infantes Museum).

This new species is called Arcanosaurus ibericus, that means “mysterious Iberian reptile”, a justifiable name because “it remains somewhat mysterious in spite of the fact that we have studied it, because we are not sure of its place in the Varanoidea family”, as DiCYT was told by Fidel Torcida, Director of the Museo de los Dinosaurios de Sala de los Infantes.

The 29 vertebrae used to conduct the study are “fairly complete remains, from neck to tail” of a 4-feet animal from the Early Cretaceous. In fact, a few days ago a study was released identifying another lizard of the Varanoidea family in Cuenca (Spain), but in this case it was from the Late Cretaceous, that is, a more modern animal.

Nevertheless, “the Iberian Peninsula is not plenty of specimens”, so these findings are very valuable in order to “rebuild this epoch’s ecosystem”, which dinosaurs such as Demandasaurus darwini have been found in this area (Sierra de la Demanda).

Data collected by scientists suggest the existence of “an alluvial plain frequently overflowing, a mud-rich area containing subtropical vegetation”, Fidek Tordica states. In this context, there must had been animals such as crocodiles and a turtle called Larachelus morla, also found at the site, although it is five million years older than the lizard.

Analysis at the European Synchrotron Radiation Facility (Grenoble)

Researchers have managed to classify the specimen as a terrestrial animal because, besides performing the routine anatomical description and comparing it with other animals to place it as another species, they have analyzed internal bone material in the Synchroton Facility in Grenoble (France).

Arcanosaurus ibericus remains were collected by the Colectivo Arqueológico Paleontológico de Salas de los Infantes (an archaeological paleontological group at the site) in the 90s, before setting up the museum, which explains the reason why the article lasted that long to be published, confirming the existence of this new fossil species. Moreover, it is important to understand that this type of analysis requires a preparation period to separate stones and bones and, in this case, “we had a hard time looking for experts” and three years of scientific revisions until the article was accepted by the journal.

The authors, besides Fidel Torcida, are Alexandra Houssaye (Universität Bonn, Germany), Jean-Claude Rage and Nathalie Bardet (Muséum national d’histoire naturelle, France), Xavier Pereda (Euskal Herriko Unibertsitatea, Spain) and Pedro Huerta (Universidad de Salamanca, Spain).

Two New Dinosaurs

The Museo de los Dinosaurios de Salas de los Infantes stores thousands of fossils from sites in the area, that is why they are sure, even if there aren’t any scientists entirely devoted to this work, they will find new species. Specifically, in the absence of published research corroborating it, two new species of dinosaur are likely to be soon incorporated; one of them belongs to the Sauropoda order (just like Demandasaurus darwini) and the other to a small-sized dinosaur species. Notwithstanding, description work is usually long-lasting, Fidel Torcida explains.




Alexandra Houssaye, Jean-Claude Rage, Fidel Torcida Fernández-Baldor, Pedro Huerta, Nathalie Bardet, Xabier Pereda Suberbiola. A new varanoid squamate from the Early Cretaceous (Barremian–Aptian) of Burgos, Spain. Cretaceous Research.