It has been suggested that an ancestor of Europasaurus would have quickly decreased in body size after emigrating to an island that existed at the time, as the largest of the islands in the region around northern Germany was smaller than 200,000 km (120,000 mi) squared, which may not have been able to support a community of large sauropods.
Alternately, a macronarian may have shrunken concurrently with a larger landmass, until achieving the size of  Europasaurus.
Previous studies on insular (island) dwarfism are largely restricted to the Maastrichtian of Haţeg Island in Romania, home to the dwarf titanosaur Magyarosaurus and the dwarf hadrosaur Telmatosaurus.
Telmatosaurus is known to be from a small adult, and although it is very small, Magyarosaurus specimens of small sizes are known to be from adult to old individuals.
Magyarosaurus dacus adults were a similar body size to Europasaurus, but the largest of the latter had longer femora than the largest of the former, while Magyarosaurus hungaricus was significantly larger than either taxon.
The dwarfism in Europasaurus represents the only significant rapid body mass change in derived Sauropodomorpha, with the general trend of taxa being a growth in overall size in other groups.
It has been suggested that an ancestor of Europasaurus would have quickly decreased in body size after emigrating to an island that existed at the time, as the largest of the islands in the region around northern Germany was smaller than 200,000 km (120,000 mi) squared, which may not have been able to support a community of large sauropods. Alternately, a macronarian may have shrunken concurrently with a larger landmass, until achieving the size of  Europasaurus. Previous studies on insular (island) dwarfism are largely restricted to the Maastrichtian of Haţeg Island in Romania, home to the dwarf titanosaur Magyarosaurus and the dwarf hadrosaur Telmatosaurus. Telmatosaurus is known to be from a small adult, and although it is very small, Magyarosaurus specimens of small sizes are known to be from adult to old individuals. Magyarosaurus dacus adults were a similar body size to Europasaurus, but the largest of the latter had longer femora than the largest of the former, while Magyarosaurus hungaricus was significantly larger than either taxon. The dwarfism in Europasaurus represents the only significant rapid body mass change in derived Sauropodomorpha, with the general trend of taxa being a growth in overall size in other groups.
Europasaurus