CLASSIFICATION OF VERTEBRATA 21 



Eecent distribution of Testudinidae cosmopolitan, with the 

 exception of the Australian region. 



Chelonidae. Limbs transformed into paddles. With 

 squamoso-parietal suture. Marine. 



Since upper Chalk in Europe and North America. 



Eecent : Chelone and Thalassochelys. 



2. Sub-order PLEUEODIEA, Dumeril. Neck bending 

 laterally. Pelvis anchylosed with plastron and carapace. 



Here possibly Proganochelys. Ehaetic, Wuerttemberg. 

 Pelomedusidae. With eleven plastrals. Eecent, Africa, 

 Madagascar, South America. 



?Plesiochelys. Upper Jurassic, Switzerland. 

 Chelydidae. With nine plastrals. Eecent : Chelys fim- 

 briata = matamata ; Hydraspis and Hydromedusa. South 

 America. 



Chelodina. Australian region. 



Carettochelydidae. Limbs transformed into paddles. With- 

 out epidermal shields. With nine plastrals. 

 Carettochelys insculpta. New Guinea. 



3. Sub-order TEIONYCHOIDEA, Bonaparte. Neck bend- 

 ing in an S -shaped curve in a vertical plane. Pelvis not 

 anchylosed. With nine plastrals. With three claws. With- 

 out epidermal shields. Since the upper Chalk in N. America ; 

 Eocene in Europe and U.S.A. 



Eecent : Trionyx in Asia, Africa, North America. 

 2. Order Athecae, Cope. Sphargidae. Dorsal vertebrae 

 and ribs not fused with the carapace, which consists of numerous 

 polygonal plates. Pelvis not anchylosed. Without parieto- 

 pterygoid column. Limbs transformed into paddles. Skin 

 leathery, without epidermal shields. Marine. Potentially 

 cryptodirous. 



?Psephoderma. Ehaetic, Bavaria. 

 Protostega gigas. Upper Chalk, U.S.A. 

 Protosphargis. Upper Chalk, Venetia. 

 Eosphargis. London Clay. 

 Psephophorus. Oligocene, Europe. 



Eecent : Sphargis (Dermatochelys) coriacea. Intertropical. 

 Total number of recent Chelonian species about 200. 



