ORDER TESTUDINES TURTLES AND TORTOISES FAUNA PARAGUAY

ORDER TESTUDINES (=CHELONIA, =TESTUDINATA) - TURTLES AND TORTOISES
The sole living Anapsid order, the Testudines are distinctive on account of their bony carapace (shell). Some recent studies have suggested that the skull of the members of this order is secondarily-roofed and that it may be more properly treated in the Diapsida. Three families of Testudines (Testudinidae, Chelidae and Kinosternidae) classified into two suborders (Pleurodira and Cryptodira) occur in Paraguay.
The carapace is formed by bony dermal plates overlaid by large epidermal scales. Eight cervical vertebrae all have ribs associated and of the 10 trunk vertebrae 8 have ribs usually united with the carapace. There is no sternum or sternal ribs and the limb girdles are inside the rib cage. The quadrate is fixed and the jaws toothless, typically a horny beak is present. Pelvis is fused to the carapace and plastron. The cloacal opening is round or longitudinal. Males possess an extensile penis located anterior to the cloaca. Adults are oviparous laying shelled, terrestrial eggs. Typically eggs of this order are rounded with a soft, leathery shell.

Key to the Families and Species of Paraguayan Testudines

1a Terrestrial with high, domed carapace and strong, thick legs with large, well-defined scales...... Testudinidae 3
1b Aquatic, with low, somewhat flattened carapace and flattened limbs adapted for swiming.......................... 2

2a Carapace with pronounced longitudinal furrows either side of medial line. Plastron hinged. Neck short.....................................................................................................     Kinosternidae - Kinosternon scorpioides
2b Carapace lacking longitudinal furrows either side of medial line, though may have a single indistinct medial furrow. Plastron unhinged. Neck frequently long ............................................................................. Chelidae   4

3a Carapace mostly yellow with black outer edges to the dorsal plates. Head black. Legs lacking red spots........................................................................................................................................... Chelonoidis petersi
3b Carapace mostly black with large, square yellow spot on each dorsal plate. Head extensively yellow on dorsal surface. Legs spotted with red.............................................................................................. Chelonoidis carbonaria

4a Extended neck greater than half the length of carapace. No chin barbels. Black bordered light stripe runs from upper jaw along neck. ..................................................................................................... Hydromedusa tectifera
4b Extended neck less than half length of carapace. Chin barbels present (though may be small) .................... 2

5a Carapace flattened or mildly domed. Lateral marginals of carapace obviously narrowed. ........................... 6
5b Carapace flattened. Snout blunt, not pointed. Lateral marginals of carapace not obviously narrowed .............................................................................................................................................................. Phrynops 8

6a Carapace mildly domed with low medial groove. Broad head and neck considerably shorter than carapace. Nose pointed. Eye with lateral bar. Often aggressive. Small barbels. ............................ Mesoclemmys vanderhaegei
6b Carapace flattened with shallow medial groove. Broad head and long neck. Eye without lateral bar. Barbels present and dorsal surface of head bears tubercles. ..................................................................... .Acanthochelys 7

7a Carapace length <18cm. Wide yellowish medial stripe on head bordered by two paler greyish stripes, clearly defined. Legs yellow. ................................................................................................... Acanthochelys pallidipectoris
7b Carapace length up to 24cm. Head uniformly dark greyish-brown above and yellowish below, with zone of demarcation ill-defined. Limbs grey on the outside, yellow underneath. ..........................Acanthochelys macrocephala

8a Dorsal surface of head mostly pale with dark lateral and dorsal stripes. Plastron pale with dark vermiculations on each plate.................................................................................................    Phrynops geoffranus
8b Dorsal surface of head dark. Plastron uniformly pale or with large dark blotches. Not vermiculated. ......... 9

9a Head dorsally dark, ventrally pale, with dark longitudinal line running from the snout, through the eye to the rear of the head and large dark blotches on underside of neck. Carapace uniformly dark with yellow edges. Plastron yellow with large dark blotches on each plate...............................................................   Phrynops hilarii
9b Head dorsally and ventrally dark with thin yellowish lateral lines on sides of head. Carapace dark brownish, ornamented with black radial lines. Plastron uniformly yellowish or yellowish-brown, lacking conspicuous darker markings. ......................................................................................................................   Phrynops williamsi

REFERENCES
Fouquette MJ (unpublished) - Synopsis of Recent Reptiles to Genus - Arizona University
McCord WP, Joseph-Ounmi M, Lamar WW 2001 - A Taxonomic Reevaluation of Phrynops (Testudines: Chelidae) with the Description of Two New Genera and a New Species of Batrachemys - Revista Biologia Tropical 49: p715-764.
Tortoise and Freshwater Turtle Working Group - Checklist of the Chelonians of the World
Whitfield P Ed.1984 - Longman Illustrated Animal Encyclopedia - Guild Publishing, London.