Diversity in the matrix structure of eggshells in the Testudines (Reptilia).

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.

Extensive morphological convergence and rapid radiation in the evolutionary history of the family Geoemydidae (old world pond turtles) revealed by SINE insertion analysis.

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.

First application of the SINE (short interspersed repetitive element) method to infer phylogenetic relationships in reptiles: an example from the turtle superfamily Testudinoidea.

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).

Phylogenetic relationships of the Asian box turtles of the genus Cuora sensu lato (Reptilia: Bataguridae) inferred from mitochondrial DNA sequences.

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.