Terrapins are reptiles, not amphibians. They belong to the family Emydidae, which encompasses several species of turtles that primarily inhabit brackish waters, such as those found in coastal marshes and estuaries.
One of the key characteristics that categorize terrapins as reptiles is their scaly skin, which is essential for water retention and protection from predators. Unlike amphibians, which typically have moist skin that allows for respiration through their skin, reptiles have adapted to life on land with tougher, drier skin that helps minimize water loss.
Additionally, terrapins lay eggs that have a hard shell, another hallmark of reptiles. In contrast, amphibians usually lay soft, gelatinous eggs in water. The developmental process of terrapins also reflects reptilian traits, as they undergo an egg stage that is distinct from the aquatic larval stages seen in many amphibian species.
In summary, considering their physical and reproductive characteristics, terrapins are classified as reptiles, marking them as distinct from amphibians.