Europasaurus was discovered in a bonebed as a herd. One suggestion has been that the herd was swept out to sea from a beach, drowning before becoming buried in the seabed. The only land near where the herd would have perished was a chain of small islands, the largest 200,000 km2, or 124,300 square miles. An area this small would have not been able to support Europasaurus' larger ancestors, forcing them to depreciate in size.