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Current Herpetol. 20(2) 2001 



pass through the posterior opening between 

 carapace and plastron (Waagen, 1984; 

 Moll, 1985). Sexually dimorphic plastral 

 kinesis is present in Geoeinyda japonica, 

 G. spengleri (see Yasukawa et al. [1992]), 



G. silvatica (see Moll et al. [1986]), Heos- 

 emys grandis (Yasukawa unpublished data), 



H. spinosa (see Moll [1985]), Melanochelys 

 tricarincita (see Waagen [1984]), and Rhino- 

 clem mys spp. (see Pritchard and Trebbau 

 [1984]). Therefore, all members of the 

 Geoemyda group exclusive of Melanochelys 

 trijuga actually show plastral kinesis at least 

 in adult females. Considering its sporadic 

 emergences on the phylogenetic tree of 

 the Geoemyda group, it is probable that 

 sexually dimorphic plastral kinesis repre- 

 sents a primitive condition in this group. 



Taxonomic notes 



Based on the strong plastral buttresses 

 in Maiiremys annamensis. Savage (1953) 

 revalidated the monotypic genus Annam- 

 emys Bourret 1939, for this species. He 

 also suggested its close affinity to several 

 batagurines with strong plastral buttresses, 

 such as Batagur, Callagiir, Hardella, and 

 Kachuga. On the other hand, Iverson and 

 McCord (1994), in the analyses of morpho- 

 metric variation in the East Asian Maur- 

 emys, regarded annamensis as the closest 

 relative of M. mutica, and synonymized 

 Annamemys with Mauremys again. The 

 present study showed that the buttress of 

 M. annamensis is stronger than that of 

 other geoemydines, but much less devel- 

 oped than that of the above-mentioned 

 batagurines (see comments for characters 

 28 and 29). Except for the buttress, this 

 species shared most character states with 

 M. mutica, supporting Iverson and 

 McCord's (1994) account (Table 1). 

 Assignment of this species to the genus 

 Mauremys was also supported by a recent 

 mithochondrial DNA study, which, how- 

 ever, suggested the closest affinity of M. 

 annamensis with M. iversoni rather than 

 with M. mutica (Honda et al., in press). 



The NJ phylogram, while supporting the 

 aurocapitata-pani-trifasciata-mccordi-zhoui 

 assemblage, showed that Cu. amboinensis, 

 the type species of the genus, is highly 

 differentiated from the other congeners. 

 Such a relationship was also supported by 

 the cladogram as well. However, we found 

 no character states definitely uniting the 

 five species. Therefore, we do not further 

 divide this genus. 



Of the currently recognized species of 

 Cuora (sensu lato), Cu. yunnanensis from 

 Yunnan, China, was not examined in our 

 study. Examining all syntypes (=all avail- 

 able specimens since the description by 

 Boulenger [1906]) of this rare species, 

 Ernst (1988) demonstrated a close rela- 

 tionship of Cu. yunnanensis with Cu. tri- 

 fasciata. McCord and Iverson (1991) also 

 suggested a close affinity of Cu. yunnan- 

 ensis with Cu. trifasciata, as well as with 

 Cu. pani and Cu. aurocapitata on the 

 basis of morphometric comparisons 

 among all extant Cuora (sensu lato). 

 Therefore, we tentatively retain this spe- 

 cies in the genus Cuora (sensu stricto). 



Geoemyda silvatica is an enigmatic 

 species endemic to the Western Ghats of 

 southwestern India (Das, 1991; 2001). Its 

 generic allocation has been in dispute. 

 Some authors assigned this species to 

 Geoemyda, while others assigned it to 

 Heosemys (see the Geoemyda subsection 

 in "Materials and Methods"). Such a 

 taxonomic confusion is probably attribut- 

 able to the paucity of studies directly 

 comparing specimens of G. japonica, G. 

 silvatica, and G. spengleri. We examined 

 representatives of all these species in 

 detail, and our results strongly suggest the 

 monophyly of the three species and the 

 validity of the G. Japonica-G. spengleri 

 clade. 



Of the currently recognized species of 

 Rhinoclemmys (sensu lato) R. melanosterna, 

 R. diademata, and R. nasuta were not 

 examined. They were once treated as 

 subspecies of R. punctularia, and then 



