The epiphyseal line is a remnant of the growth plate, known as the epiphyseal plate, found in long bones. This line appears after the bone has finished growing in length, typically during late adolescence or early adulthood. It marks the area where new bone was formed during growth, indicating that the bone has reached its mature size. The epiphyseal line is important for understanding bone development and growth. In children and adolescents, the epiphyseal plate allows for the elongation of bones, which is crucial for overall height. Once growth is complete, the plate ossifies, leaving the epiphyseal line as a sign of the bone's growth history.