120 



Current Herpetol. 20(2) 2001 



markings on plastron. The Notochelys- 

 Cyclemys clade (Stem G) was supported by 

 three synapomorphic character states: 21 

 (1), plastral hinge not closing without gap; 

 28 (3), very weak axillary plastral buttress; 

 and 30 (2), internal choanae usually with a 

 small papillia. Monophyly of Heosemys 

 (Stem H) was supported by two synapo- 

 morphic character states: 6 (1), loss of 

 quadratojugal; and 30 (0), internal choanae 

 without ridge, flap, or papillae. The latter 

 was unique among the geoemydines. 

 Heosemys was the sister group of the 

 Notochelys-Cyclemys clade. 



Stem I was supported by two synapo- 

 morphic character states: 15 (1), foramen 

 praepalatinum sometimes opening within 

 premaxilla; and 18 (2), processus trochle- 

 aris oticum mainly formed by the 

 quadrate. Stem J was supported by two 

 synapomorphic character states, 9 (1: 

 usually flat jaw beak) and 31 (1: smooth 

 posterior head skin), whereas M. trijuga 

 had one autoapomorphic character state, 

 24 (1: three prominent keels). 



Rhinoclemmys was shown to be poly- 

 phyletic, consisting of two groups, Rhino- 

 clemmys A (areolata, fiinerea, punctularia 

 and pulcherrima) and Rhinoclemmys B 

 (an nu lata and nibida). The Rhinoclemmys 

 A-Cuora clade (Stem K) was supported by 

 three character states: 11 (1), very weak 

 serration of upper labial margin; 14 (2), 

 absence of the maxilla-vomer contact; and 

 15 (2), location of foramen praepalatinum 

 within premaxilla. Within this clade, 

 monophyly of the Rhinoclemmys A (Stem 

 L) was supported by two character states, 8 

 (0: the jugal-quadratojugal contact) and 9 

 (0: notched and hooked beak of upper 

 jaw), whereas the R. funerea-R. punctu- 

 laria clade was supported by a unique 

 synapomorphic character state 35 (1: usual 

 presence of small foramen on ventral 

 maxilla). Cuora (Stem M) was further 

 supported by four synapomorphic character 

 states: 19 (1), quadrate participation into 

 canaHs cavernosum; 21 (1), presence of 



both plastral hinge and gap between closed 

 shells; 28 (3), very weak axillary plastral 

 buttress; and 29 (3), very weak inguinal 

 plastral buttress. The Cuora trifasciata 

 species group-Q/. mccordi clade (Stem N) 

 was supported by a unique character state: 

 16 (1), prefrontal notched at posterior 

 orbital margin. 



Although there were no synapomorphies 

 uniting the Rhinoclemmys B, the Rhino- 

 clemmys B-Cistoclemmys-Pyxidea-Geo- 

 emyda clade (Stem O) was supported by 

 three character states: 9 (2), unnotched and 

 hooked upper jaw beak; 13 (1), anterome- 

 dial portion of triturating surface expanding 

 medially; and 20 (1), reduction of hyoid 

 apparatus. 



Monophyly of the Cistoclemmys-Pyxidea- 

 Geoemyda clade (Stem P) was supported 

 by seven synapomorphic character states, 

 3 (1), foramen nervi vidiani located 

 anteroventrally or laterally to anteroventral 

 part of processus inferior parietahs; 4 (1), 

 medial process of jugal with small tip; 27 

 (1), strong reduction or loss of cloacal 

 bursae; 2 (2), strong ventral convergence of 

 cranial cavity; 5 (1), usual absence of the 

 jugal-pterygoid contact; 12 (1), small and 

 round foramen palatinum posterius; and 24 

 (1), three prominent keels on carapace. 

 The former three were unique among geo- 

 emydines. The Cistoclemmys-Pyxidea clade 

 (Stem Q) was monophyletic on the basis of 

 four character states: 15 (0), foramen prae- 

 palatinum located between premaxilla and 

 vomer; 21 (1), presence of plastral hinge; 

 28 (3), very weak axillary plastral buttress; 

 and 29 (3), very weak inguinal plastral 

 buttress. Validity of Cistoclemmys (Stem 

 R) was supported by five synapomorphic 

 character states: 21 (2), plastral hinge 

 closing shell without gap; 22 (2), absence 

 of anal notch of plastron; 24 (0), usual 

 absence of lateral keels on carapace; 26 (1), 

 presence of sutures between lateral sides of 

 seventh and eighth pleurals; and 34 (1), 

 very long anterodorsal portion of iliac 

 blade (unique in geoemydines. Fig. Ic, d). 



