When Magyarosaurus was discovered in Transylvania (then part of the Austro-Hungarian Empire), the palaeontologist Nopcsa advanced the idea that Magyarosaurus was an island dwarf, but he could not prove it back then, at the beginning of the 20th century. Many discoveries have since indicated that his theory might be correct, especially the fossils of dwarf elephants and hippopotamuses found on Mediterranean islands like Sicily, Malta and Cyprus.
However, scientists first pursued a different theory. For in the subsequent decades, other researchers found big sauropod bones on the Transylvanian site. They therefore concluded that Magyarosaurus was simply a youngster, while the larger bones came from fully grown adults.
The study now being published provides conclusive evidence that Nopcsa's hunch had been right all along. "Our study shows that dinosaurs on islands were subject to the same ecological and evolutionary processes that shape modern mammals," explains Martin Sander. "We were also able to demonstrate that the bigger bones found in that area belong to a different dinosaur species." Whether they come from stray animals who swam to the island from the mainland, or from large ancestors of the dwarf Magyarosaurus, remains a secret shrouded in the mists of pre-historic time.