Megalochelys atlas


Megalochelys atlas is an extinct species of giant cryptodiran tortoise from the Late Miocene through to the Early Pleistocene periods. During the dry glacial periods it ranged from western India and Pakistan to as far east as Sulawesi and Timor in Indonesia, though the island specimens likely represent distinct species. It has been suggested that Megalochelys sivalensis is the correct name for the taxon, though this is disputed.

Description

Megalochelys atlas is the largest known member of the Testudinidae, with a shell length of about, an estimated total length of, and an approximate total height of. Popular weight estimates for this taxon have varied greatly with the highest estimates reaching up to in some instances. However, weights based on volumetric displacement of the skeleton, or inferences based on two-dimensional skeletal drawings, indicate that M. atlas was probably closer to in mass. M. atlas is thus the largest known tortoise. The only larger turtles were the marine Archelon and Protostega from the Cretaceous Period, and the aquatic, freshwater Stupendemys of the South American Late Miocene.
Like the modern Galápagos tortoise, M. atlas' weight was supported by four elephantine feet. Since most members of the related genus Testudo are herbivores, paleontologists believe M. atlas had the same diet.

Taxonomy

Megalochelys atlas has a complicated nomenclatural history. It has previously been placed in the genus Colossochelys, however this name is in fact a junior synonym of Megalochelys, the statement of withdrawn by Auffenberg. Hence the correct genus is Megalochelys and the correct species is M. atlas.

Extinction

It is widely suspected that the species went extinct due to the arrival of Homo erectus, due to staggered extinctions on islands co-inciding with the arrival of H. erectus in these regions.