The European roots of Africa's giant predatory dinosaurs

Tyrannosaurus is perhaps the best-known bipedal predatory dinosaur – but not the largest known representative of this group: Spinosaurus occurred in Africa in the early Late Cretaceous period (around 95 million years ago) and was even larger, measuring up to 18 meters in length. In collaboration with Spanish colleagues, SNSB paleontologist Oliver Rauhut has now found new evidence that the gigantic spinosaurs had their roots in Europe. New finds and the re-examination of previously collected remains of the little-known predatory dinosaur Camarillasaurus cirugedae from the Lower Cretaceous period (about 128 million years ago) in Spain show that this species was a close relative of the giant North African spinosaurs.

Camarillasaurus was found in the central Spanish province of Teruel. The fossil was originally classified as a ceratosaur – a group of predatory dinosaurs little known in Europe and whose occurrence in the Lower Cretaceous of Spain would represent a find “outside of space and time,” as stated in the original publication. This interpretation was based on a few fragmentary remains described more than ten years ago. During a new excavation campaign at the original fossil site, Oliver Rauhut and his colleagues from the University of Zaragoza have now found further remains of the dinosaur, including fragments of the jaw, tail vertebra and tooth as well as a thigh bone and a foot claw. The new finds allow for the now published reinterpretation of the Spanish predatory dinosaur's family relationships. For example, the paleontologists found common features between Camarillasaurus and other spinosaurs in the lower jawbone.

Oliver Rauhut, dinosaur expert at the Bavarian State Collection of Paleontology and Geology (SNSB-BSPG), goes one step further: "Our phylogenetic analyses indicate that various other representatives of the spinosaurids of the Iberian Peninsula are also on the evolutionary lineage leading to the North African spinosaurids. We suspect that the giant predatory dinosaurs of Africa originated in Europe."

Remains of various spinosaurs, mostly teeth, are common on the Iberian Peninsula, most of them embedded in continental deposits, including Camarillasaurus cirugedae. Researchers therefore assume that the animals lived and hunted in a terrestrial environment. The North African Spinosaurus, on the other hand, is more recently interpreted as a fish eater that spent most of its time in the water, based on its anatomy. There are no finds from Spain to support this thesis as yet.