Megalainhydris was a prehistoric giant otter that lived during the Pleistocene epoch, approximately 2.5 million to 11,000 years ago. This large otter species is known from fossils found in Cuba, suggesting that it was one of the top aquatic predators in its environment. Megalenhydris had a robust body, powerful jaws, and strong limbs adapted for swimming, much like modern otters. Its size and physical adaptations imply that it preyed on fish and possibly other small aquatic creatures. The discovery of this species provides valuable insights into the diversity of prehistoric mammals in the Caribbean region.