English: Mosasaurus hoffmannii is an aquatic squamate reptile from the Late Cretaceous. It was one of the first Mesozoic marine reptiles known to science, originally discovered in Europe with more specimens found around the world. Mosasaurus is known mainly from its skull, making full body estimates difficult, but it is estimated between 11-17 m in length, making it one of the largest marine reptiles known. It had a streamlined body with a long fluked tail to propel it through the water, with four limbs adapted as paddles to steer. It was an apex predator with serated teeth, able to feed on any animal it came across.