Abstract:Monophyly of the batagurid subfamily Geoemydinae was evaluated, and phylogenetic relationships within the subfamily were inferred on the basis of 35 morphological characters. Two approaches, parsimony analysis using the branch and bound algorithm, and neighbor joining clustering of an absolute distance matrix, were used. The results of these analyses yielded phylograms that were almost identical in branching topology, and poorly supported the monophyly of Geoemydinae. This subfamily thus seems to be a metataxon, most likely consisting of the sister group of Batagurinae (Geoemyda group) and a more primitive stock of Bataguridae (Mauremys group).

The eggshells of 56 chelonians were examined by electron microscopy and X-ray diffractometry. They were classified into six types in terms of the matrix structure of their calcareous layer; type I was composed of a thin calcareous layer with minerals in an amorphous structure; type II with shell units composed of mammillary cores calcified with aragonite crystals; type III with shell units composed of mammillary cores, plus a single palisade layer also calcified with aragonite crystals, and with each shell unit separated; type IV with shell units the same as type III, but tightly packed together; type V with shell units composed of mammillary cores plus two palisade layers; and type VI with a cuticle layer calcified with calcite crystals over the same structure as that of type V. X-ray diffraction analyses at the outer surface of eggshells showed a gradual change in crystal disposition from the random disposition of type II to the single direction-oriented disposition of type V. The shell height was approximately parallel to the development of the palisade-layer matrix. The limiting membrane of all eggshell types was perforated with canals and that of type I was partially missing. Type I had a parchment shell, types II and III had a pliable shell (some were rigid) and types IV to VI had rigid shells. The present study showed that the hardness of eggshells can be determined by the composition of the shell matrices, as shell matrices are the framework for mineralization.

Phylogenetic relationships of the genus Cuora sensu lato (Cuora sensu stricto and Cistoclemmys) and other testudinoid genera were inferred from variations in 882 base positions of mitochondrial 12S and 16S rRNA genes. Results yielded a robust support to the monophyly of a group (Cuora group) consisting of Cuora sensu lato and the monotypic Pyxidea. Within the Cuora group, the continental Cuora (sensu stricto) and the two subspecies of Ci. flavomarginata constituted two well-supported monophyletic groups. Distinctly small interspecific genetic distances in the former groups suggested that in the continent speciations in Cuora took place much later than the primary divergences in the Cuora group, or speciations in other related genera, such as Mauremys. Our analyses failed to provide a substantial support to the monophyly of any other combinations of taxa within the Cuora group, including Cuora in broad and strict senses, and Cistoclemmys as consisting of Ci. galbinifrons and Ci. flavomarginata. Besides these, our results also suggested the non-monophyly for the Batagurinae and the Geoemydinae, and sister relationships of the Bataguridae with Testudinidae rather than with the Emydidae.

Although turtles (order Testudines) constitute one of the major reptile groups, their phylogenetic relationships remain largely unresolved. Hence, we attempted to elucidate their phylogeny using the SINE (short interspersed repetitive element) method, in which the sharing of a SINE at orthologous loci is indicative of synapomorphy. First, a detailed characterization of the tortoise polIII/SINE was conducted using 10 species from eight families of hidden-necked turtles (suborder Cryptodira). Our analysis of 382 SINE sequences newly isolated in the present study revealed two subgroups, namely Cry I and Cry II, which were distinguishable according to diagnostic nucleotides in the 3' region. Furthermore, four (IA-ID) and five (IIA-IIE) different SINE types were identified within Cry I and Cry II subgroups, respectively, based on features of insertions/deletions located in the middle of the SINE sequences. The relative frequency of occurrence of the subgroups and the types of SINEs in this family were highly variable among different lineages of turtles, suggesting active differential retroposition in each lineage. Further application of the SINE method using the most retrotranspositionally active types, namely IB and IC, challenged the established phylogenetic relationships of Bataguridae and its related families. The data for 11 orthologous loci demonstrated a close relationship between Bataguridae and Testudinidae, as well as the presence of the three clades within Bataguridae. Although the SINE method has been used to infer the phylogenies of a number of vertebrate groups, it has never been applied to reptiles. The present study represents the first application of this method to a phylogenetic analysis of this class of vertebrates, and it provides detailed information on the SINE subgroups and types. This information may be applied to the phylogenetic resolution of relevant turtle lineages.

The family Geoemydidae is one of three in the superfamily Testudinoidea and is the most diversified family of extant turtle species. The phylogenetic relationships in this family and among related families have been vigorously investigated from both morphological and molecular viewpoints. The evolutionary history of Geoemydidae, however, remains controversial. Therefore, to elucidate the phylogenetic relationships of Geoemydidae and related species, we applied the SINE insertion method to investigate 49 informative SINE loci in 28 species. We detected four major evolutionary lineages (Testudinidae, Batagur group, Siebenrockiella group, and Geoemyda group) in the clade Testuguria (a clade of Geoemydidae + Testudinidae). All five specimens of Testudinidae form a monophyletic clade. The Batagur group comprises five batagurines. The Siebenrockiella group has one species, Siebenrockiella crassicollis. The Geoemyda group comprises 15 geoemydines (including three former batagurines, Mauremys reevesii, Mauremys sinensis, and Heosemys annandalii). Among these four groups, the SINE insertion patterns were inconsistent at four loci, suggesting that an ancestral species of Testuguria radiated and rapidly diverged into the four lineages during the initial stage of its evolution. Furthermore, within the Geoemyda group we identified three evolutionary lineages, namely Mauremys, Cuora, and Heosemys. The Heosemys lineage comprises Heosemys, Sacalia, Notochelys, and Melanochelys species, and its monophyly is a novel assemblage in Geoemydidae. Our SINE phylogenetic tree demonstrates extensive convergent morphological evolution between the Batagur group and the three species of the Geoemyda group, M. reevesii, M. sinensis, and H. annandalii.

Phylogenetic relationships of the freshwater turtles of the genus Mauremys and representatives of several other batagurid genera were inferred from variations in 863 base positions of mitochondrial 12S and 16S rRNA genes. Results strongly suggested the non‐monophyly of Mauremys by indicating the closest affinity of Mauremys japonica with Chinemys reevesii, the type species of the genus Chinemys. Recent morphological analyses of the batagurid genera suggested that Mauremys is a basal stock of the subfamily Geoemydinae, whereas Chinemys is a member of the subfamily Batagurinae as supported by several putative synapomorphs with other batagurine genera. It is thus probable that the morphological character states used to define Mauremys actually represent symplesiomorphy, and that morphological character states shared between Chinemys and other batagurine genera have resulted from convergence. Also, our results did not support a sister‐group relationship between Mauremys annamensis and Mauremys mutica, which has been implicitly or explicitly assumed by a number of previous authors on the basis of morphological data. Instead, M. annamensis was indicated to be closest to Mauremys iversoni, a species assumed to be most divergent among the East Asian Mauremys by previous authors.

The batagurid turtle, Mauremys mutica, is widely distributed in tropical to temperate East Asia. Analyses of morphometric characters and coloration revealed that the southern Ryukyu populations of this species are much diverged from the other populations, presumably as a result of their long geographical isolation. We describe those populations as a new subspecies, M. m. kami. Analysis of geographic variation also suggested that distinctly isolated populations of the central and northern Ryukyus, and Kyoto and Shiga Prefectures of central Japan have originated from animals artificially introduced from the Yaeyama Group, and Taiwan, respectively. We confirmed the absence of "larger female" sexual size dimorphism (SSD) in M. mutica unlike most other aquatic batagurids, and further demonstrated variation in SSD pattern between the subspecies: in M. m. kami, the adult male has a significantly greater carapace length than adult females, whereas the adult carapace length does not differ significantly between sexes in the nominotypical subspecies. It is hypothesized that these dimorphic patterns evolved from the widely prevailing "larger female" condition through epigamic selection involving forcible copulatory behavior.

summarY. -The Japanese pond turtle, Mauremys japonica (Family Geoemydidae), is endemic to Japan and is distributed in Honshu, Shikoku, Kyushu, and adjacent small islands. The turtle is found in various freshwater habitats such as swamps, marshes, irrigated rice paddies, ponds, lakes, and rivers. Many of these habitats have been the objects of recent rapid land developments, or under the constant influences of human activities, obviously involving population declines of this species. The overexploitaion by pet dealers and the prevalence of artificially introduced species with similar ecological requirements could be reducing the numbers of this turtle as well. Thus, although the turtle seems still to be relatively abundant in most districts, preservation of its habitats, as well as regulations for the handling of this species and the control of invasive turtles (especially of the red-eared slider Trachemys scripta elegans) should be considered urgently for the conservation of this species. Accumulation of field data for various ecological aspects of the Japanese pond turtle is also strongly desired in order to formulate effective conservation actions.disTribuTion. -Japan. Restricted to Honshu, Kyoshu, and Shikoku. sYnonYmY. -Emys vulgaris japonica Temminck and Schlegel 1835;