Among all the reptiles in the world, turtles are the most popular because they can be kept as pets, though others prefer them for their meat and beautiful shells. One of the species that have the ability to live both on land and water, they come in different sizes and colors, while a few are weird-looking as well. Despite having a bad rep as disease-carriers and for being aggressive, a lot of people still prefer to care for them since some of their species are already endangered.

In celebration of World Turtle Day on May 23, 2013, here are the weirdest turtles in the world that everybody loves.

10. Spiny Softshell Turtle (Apalone spinifera)

Photo Source: http://perpustakaan.blogspot.com/2009/11/weird-and-cute-turtles.html

A species of softshell turtle, the bizarre-looking spiny softshell turtle is one of the largest freshwater species found in the United States, Canada and Mexico. They were named from their spiny, cone-like projections on the edge of their shells, which are not scales, and six subspecies are recognized that have different markings on the sides of the head, feet and on their carapace. However, these markings are only distinct in hatchlings since they usually fade once the turtles grow. First described by Charles Alexander Lesueur in 1827, adults of the various subspecies are not distinguishable from one another, so their subspecies are only assigned based on their geography, though the adult females are usually larger than the males.

9. Leatherback Turtle (Dermochelys coriacea)

Photo Source: http://www.virginiaherpetologicalsociety.com/reptiles/turtles/leatherback-sea-turtle/leatherback_sea_turtle.htm

Sometimes called as the ‘lute turtle,’ the leatherback sea turtle is considered as the largest of all living turtles and the fourth largest reptiles after three species of crocodiles at 3m and 916kg. It is distinguished from other sea turtles by its carapace that is covered by skin and oily flesh instead of a bony shell. Due to its large, teardrop-shaped body, it can dive to depths of 4200 feet, making it the world’s deepest-diver among all reptiles. It also holds the record for being the fastest reptile with the speed of 9.8m/s in the water. Though initially named by Domenico Agostino Vandelli in 1761 as Testudo coriacea when it was first captured, it was later reclassified in 1816 as Dermochelys coriacea due to its leathery texture and appearance; hence its first names as ‘leathery turtle’ and ‘trunk turtle.’

8. Eastern Long-neck Turtle (Chelodina longicollis)

Photo Source: http://www.flickr.com/photos/blackdiamondimages/5426537012/

Included on the weirdest list not only for its appearance, the eastern long-neck turtle has some interesting traits as well. When it feels threatened, it will emit a very offensive smelling fluid coming from its musk glands, making it earn the name ‘stinker.’ Its most distinctive feature is its long neck, so it bends its head into it shell instead of directly pulling it back like other turtles. It also has a powerful webbed feet and a flattened, broad brown shell with black-edged scutes. Distinctive black lines or seams are also found on its underside plates and they prefer slow-moving freshwater habitats like dams, swamps and the lakes of Australia.

7. Argentine Snake-necked Turtle (Hydromedusa tectifera)

Photo Source: http://animal-world.com/encyclo/reptiles/turtles/ArgentineSnakeNeckedTurtle.php

A species of turtle known for its long neck, hence its name, the Argentine snake-necked turtle is one of the most traded pets among the exotic animals. Though it originated from South America and locally found in Brazil, Argentina, Paraguay, and Uruguay, it actually came from Australia. Despite being known as the South American snake-necked turtle, it is more closely related to the Mata-mata. It can reach up to 11 inches in length and has a carapace or shell that is strongly keeled. It can also be distinguished by its black and yellow markings on its head and neck with the females usually larger and have larger tails than the males.

6. Alligator Snapping Turtle (Macrochelys temminckii)

Photo Source: http://hobbycanbefun.blogspot.com/2011/02/alligator-snapping-turtle-macrochelys.html

One of the largest freshwater turtles in the world, the alligator snapping turtle is known for its big, heavy head and long thick shell with three dorsal ridges of large scales, which make it look like the plated dinosaurs. It also known for eating anything it catches from snakes, alligators, and other turtles. Though they are often captive-bred as pets and available in the exotic animal trade, they only make good pets for experienced aquatic turtle keepers, who can determine the sex of the alligators based on the temperature at which they are incubated.

5. Cantor’s Giant Soft-shelled Turtle (Pelochelys cantorii)

Photo Source: http://www.turtlesurvival.org/blog/1-blog/167-field-surveys-for-wild-rafetus

A strange-looking species of freshwater turtles, the Cantor’s giant soft-shelled turtle is known for its broad head, small eyes near the tips of its snout, and smooth and olive-colored carapace. The juveniles have dark-spotted heads and carapaces, with yellow around it, while the adult can grow as much as 6 feet in length and weigh more than 100 pounds.  It is also known for its unique ability to spend most of its time buried and motionless underneath the sand with only its eyes and mouth showing, while surfacing only twice daily to take a breath.

4. Barbour’s Map Turtle (Graptemys Barbouri)

Photo Source: http://www.flickr.com/photos/nclarkii/3116117688/

Found in the rivers of southern Alabama, southwestern Georgia, and the western panhandle of Florida, the Barbour’s map turtle is named after the American herpetologist Thomas Barbour. It can grow at an average of 3.5 to 5.5 inches in carapace length, though the females can attain imposing dimensions from 6 to 12.5 inches with their heads enormously enlarged. The males, however, have black-tipped spines on their 2nd, 3rd, and 4th vertebrae, which resembles a dorsal fin. Their diet mostly consists of small fish, insects and mollusks; and their ownership is outlawed both in Alabama and Georgia, while species below 4 inches in length are not allowed to be sold in Florida.

3. Spiny Turtle Heosemys spinosa)

Photo Source: http://www.arkive.org/spiny-turtle/heosemys-spinosa/image-G21398.html

One of the most unusual-looking turtles in the world, the very attractive spiny turtle prefers the lowland and hilly rainforest of up to 900m with small streams nearby in areas in the Philippines, Thailand, Brunei, Indonesia, Myanmar, Malaysia and Singapore. Also known as the ‘cog-wheel turtle,’ its name was derived from its sharp, pointed and spiky-edged carapace, and spiny keel. Though nothing is known about their nesting behavior, their behavior appears to be triggered by the rain. Females, which develop a plastron hinge to ease laying of eggs, lay one or two eggs per clutch and produce three clutches per year with incubations of 106, 110 and 145 days in captivity.

2. Indian Flap-shelled (Lissemys punctata)

Photo Source: http://m.animal.memozee.com/m.view.php?q=lissemys+punctata&p=4&lang=kr

The Indian flap-shelled turtle is a cute-looking turtle that is endemic to Bangladesh, India, Myanmar, Nepal, Pakistan, and Sri Lanka in South Asia and was later introduced to the Andaman and Nicobar Islands. A freshwater species of turtle, it derives its name from the femoral flaps on its plastron, which cover the limbs when they retract into the shell. Its carapace, which range from 240 to 370mm in length, is broadly oval in adults; though it is more circular and wider with the young. It is known to be omnivorous and feeds on the diet of fish, frogs, snails, shrimps, aquatic vegetation, flowers, plant leaves, fruits, seeds, and grasses.

1. Mata mata (Chelus fimbriatus)

Photo Source: http://petra-aqua.com/nove_zbozi.php?lang=en&page=2

A freshwater turtle found primarily in the Amazon and Orinoco basins in South America, the Mata mata has a shell that resembles a piece of bark, while its head resembles the leaves falling, which camouflaged its presence. The weird-looking reptile is a large sedentary turtle that has a large triangular flattened head with many tubercles and flaps, a horn on its long tubular snout, three barbels on its chin, and four additional filamentous barbels on its upper jaw. It also has a brown or black carapace and measures 18 inches in adult age and weighs 15kg. An adult has a grayish brown head, neck, limbs, and tail with its neck longer than the vertebra under its shell and has five webbed claws in each of its forefoot. Hatchlings, meanwhile, have a pink or reddish tinge underside of their shell and plastron, which gradually disappears as they grow.