Elasmosaurus platyurus

Elasmosaurus was a long-necked marine reptile from the Late Cretaceous period, known for its incredibly elongated neck, which made up about half of its total body length—around 10 meters in total, with its neck stretching up to 7 meters. This iconic plesiosaur had a relatively small head, equipped with sharp teeth designed for catching fish, squid, and other marine prey. Its body, though bulky, was supported by four large, flipper-like limbs, which helped it maneuver through the water with impressive agility despite its size. Elasmosaurus's long neck likely gave it an advantage when hunting, allowing it to swiftly strike at prey while keeping most of its body hidden from view. Paleontologists believe that it may have used its neck like a hunting tool, sweeping it through schools of fish or ambushing prey from below, using surprise and speed to capture meals. Fossil evidence suggests that Elasmosaurus lived in shallow seas, where it was a top predator in its ecosystem, though it likely faced competition from other marine reptiles like the larger mosasaurs. Despite its predatory nature, Elasmosaurus was a non-mammalian reptile, closely related to modern reptiles like snakes and lizards but adapted to life in the ocean rather than on land.