Reptiles of Cat Tien National Park:Crocodile and Turtles

Wayne Van Devender et al.2006

Turtle Families of Cat Tien (all of Order Testudines)

• Bataguridae - 5 species• Platysternidae - 1 species • Testudinidae – 1 species• Trionychidae – 1 species

The Crocodile Family of Cat Tien• Crocodylidae - 1 species

Crocodylus siamensisSiamese Crocodile

•To 4000mm•This is the only crocodilian species at Cat Tien.•It was reintroduced to Bau Sau in 2002.•Hatchlings were first observed in 2005.

Order Testudines - turtles• Skull anapsid, but can have indented parts in

temporal area• Shell composed of upper and lower parts:

– Carapace = upper shell– Plastron = lower shell

• Carapace includes backbone and ribs• Legs, tail, and head can be pulled into shell• 3-4 families possible at Cat Tien

– Bataguridae – Asiatic pond turtles– Platysternidae – big-headed turtles – possibly at Cat Tien– Testudinidae – tortoises– Trionychidae – softshell turtles

Occasionally Appropriate Quantitative Hints

• Plastron (ventral shell) formulas are known for some Cat Tien turtles.

• Measure the length of the suture (seam) between scute- pairs. (E.g., measure the inter-abdominal seam. The inter-gular is usually neglected.)

• Place the seam-lengths in order, longest to shortest. (“><” means “either greater than or less than.”)

• Formula for plastron to left:AB > FE> PE > AN > GU > HU

The Bataguridae of Cat TienTail relatively short, feet without reduced number of toe

bonesSeveral aquatic and/or terrestrial formsMost species and genera now threatenedWe shall list 5 species (5 genera) observed by us at Cat

Tien: Cuora amboinensis

Cyclemys pulchristriata

Heosemys grandis

Malayemys subtrijuga

Siebenrockiella crassicollis

Cuora amboinensis Asian Box Turtle

This turtle has yellow stripes on the head and neck and well developed hinges that close the shell completely. (The individual depicted here was from Cat Tien, but it might have been released there.)

Asian Box TurtleC. amboinensis

This specimen not from Cat Tien

•To 210mm•Males are smaller than females and have a distinctly concave plastron.•Plastral formula is:AB><AN >PE>GU>FE>HU

Cyclemys tcheponensis Stripe-neck Leaf Turtle

hatchling

adult

adult

juvenile

juvenile

This turtle may occur on land or in permanent water, but we have found it most frequently in ephemeral pools at the beginning of the rainy season.

Stripe-neck Leaf Turtle C. tcheponensis

•To 220mm•A low medial keel is present in adults.•The posterior of the plastron is notched.•The plastral formula is variable:AB><PE>GU><AN>FE><HU

•Plastron shows dark radial bursts in juveniles but is often plain in adults.•Cat Tien specimens might be assigned to the recently described C. pulchristriata.

Heosemys grandisAsian Giant Terrapin

This large “aquatic” turtle is often found far from water, perhaps foraging for fruits, which apparently comprise much of its diet in the rainy season.

Asian Giant TerrapinH. grandis

•To 480mm•Oval carapace has posterior serrations.•A mid-dorsal keel is present.•All mid-dorsal scutes are broader than long.•Plastral scutes show a bold radiating pattern.•Plastral formula is:AB>FE>PE>AN><HU><GU

Malayemys subtrijuga

Rice-field Terrapin

This turtle may prefer soft-bottomed water bodies, but it can be found anywhere its preferred prey– aquatic snails– is present.

Rice-field TerrapinM. subtrijuga

•To 210mm•Three keels extend along the carapace, which is arched, oval, and unserrated.•The large head has distinct white stripes.•Plastral formula is:AB>FE>PE><AN>HU><GU

Siebenrockiella crassicollisBlack Marsh Turtle

This small aquatic turtle is more a bottom-walker than a swimmer and is seldom seen.

Black Marsh TurtleS. crassicollis

•To 200mm•The short jaws are curved into a “smile.”•Front legs have enlarged scales.•Posterior of carapace is strongly serrated.•Plastral formula is:AB>PE>FE>AN>GU>HU

The Platysternidae of Cat Tien

Asiatic big-headed turtle Very large head covered by one giant scaleTail quite longAquatic or semi-terrestrial Quite agile and move quicklyPlastron flat, without any hingesAlthough we have not observed this turtle at Cat Tien,

we list it because it could occur at the Park’s higher altitudes and because its presence would be of substantial interest to a number of herpetologists.Platysternon megacephalum

Platysternon megacephalumBig-headed Turtle

To 170mm The enormous head, flattened carapace, and long tail should serve to distinguish this animal from any other turtle in Cat Tien. Look for it in cooler streams at higher altitudes.

This specimen not from Cat Tien

The Testudinidae of Cat Tien

Hidden-neck turtle with with massive shellsFeet elephant-like with reduced number of toe bonesPlastron without hingesTerrestrial forms Mostly herbivorousMost species and genera now threatened

Indotestudo elongata

Indotestudo elongataElongated, or Yellow,

Tortoise

This specimen not from Cat Tien

Ina Becker

•To 360mm•Rear feet are elephantine.•Carapace is high-domed.•A greatly enlarged supracaudal scute is found above the tail.•Plastral formula is:AB>FE>PE><HU>GU>AN

•Only one of us has observed this tortoise at Cat Tien.

The Trionychidae of Cat TienSoft-shelled turtlesHidden-neck turtle without scales on the shell, head,

neck, or most of the legsLong necks end with pointed heads with snoutsFeet large and fully webbedHighly aquatic formsCan reach immense sizesMost species and genera now threatened

Amyda cartilaginea

Amyda cartilagineaSoutheast Asian Soft-

shelled Turtle

Ina Becker

Ina Becker

Gert Polet

•To 830mm•Soft-shelled turtles are characterized by their leathery shells, which are flexible at the edges.•In A. cartilaginea the anterior margin of the carapace is studded by a line of rounded tubercles.