Turtles (Chelonia, Testudines) are among the oldest now living reptiles on Earth that have evolved about 200 million years. Today we know 14 families, 90 genera and 300 species of turtles. They are divided on the basis of the possibilities for feeding the head and neck under armor on 2 suborder: hidden-neck turtle and sideneck turtles. Hidden-neck turtles are the more numerous and evolutionary successful group having 11 families, whereas sideneck turtles have only 2 families. Turtles live longer than any other reptiles and are considered to be long-lived animal. It is known that Galápagos tortoise (Geochelone nigra) can experience 150 years, and many species live about 50 years in captivity. Armour is an evolutionary novelty and their main characteristic that besides protection, has a role in facilitating hematopoiesis, serves as a storage of fat and water, and as a pH buffer. The average size of turtle armour in present day is 30 cm, but there are much larger and smaller specimens among different species. The biggest turtle Leatherback turtle (Dermochelys coriacea), which can weigh over 600 kg and 120 cm length of the carapace, and among the least belongs spider tortoise (Pyxis arachnoides) from Madagascar, which is about 10 cm long. Types of turtles can be distinguished by the following features: type of material of armour, his size, shape and colour. This information can also be used to find out information about their age, origin & lifestyle. Due to lifestyle turtles have adapted their armor and locomotor apparatus, including land turtles have two pairs of legs that end with five claws on the front feet and 4 claws on their hind legs, with a domed carapace and plastron level, while freshwater species are adapted to life in water such as between the toes have developed webbed feet, and sea turtles are with flatter and elongated shell, and with developed 2 pairs of flippers and better adaptation to their natural habitat. Skin of turtle turtle is mainly dry and thick, without a lot of glands and covered with larger or smaller scales in terrestrial turtles, while the water species are without scales, with a finer skin and mucous glands that are of importance for turtles during hibernation when hibernate buried in the mud on the bottom of the lake or river. 26 Terrestrial species are mainly herbivores, while freshwater and sea turtles are omnivores and carnivores, and land turtle claws are blunt, while the freshwater turtle claws are longer and sharper because they serve for holding prey front legs during feeding. When describing the turtle is important to take proper standard measures in order to promote their use for comparisons of scientists in their work around the world. Turtles can be measured with caliper, ruler and flexible line which is the only means of measuring range.