Gigantism and acromegaly are two disorders with the same disease mechanism and somewhat similar presentations. Even though they have the same disease mechanism, the two have entirely different outcome simply due to the age of onset. Gigantism is the result if the disease mechanism starts in childhood.
Adult Velociraptors grew up to 6.8 feet (2 meters) long, 1.6 feet (0.5 meter) tall at the hip and weighed up to 33 pounds (15 kilograms).
American lion (Panthera leo atrox / Panthera atrox) â skull. The body length of this predator ranged between 160-250 cm, and its average height at shoulders was 120 cm, with the weight of 250-360 kg. Thus, it was the largest known species/subspecies of the lion in the history of Earth. However, if its measurements were real, it is possible that this animal belonged to the jaguar or the tiger species.