The largest land turtle that ever existed was Testudo atlas (“Atlas tortoise”), also known as Colossochelys (“colossal turtle”). 8 feet long and 6 feet high, it probably weighed around 4 tons. this giant chelonian herbivore lived in the Pleistocene period
The bog turtle (Glyptemys muhlenbergii) is the smallest turtle found in the United States. The largest bog turtle ever found measured only inches. Bog turtles are easily identified by the patches of orange found along the side of their heads.