Diversity and conservation of amphibians and reptiles of a protected and heavily disturbed forest of central Mexico.

The high loss rate of forest ecosystem by deforestation in the Trans-Mexican Volcanic Belt is one of the principal ecological problems of central Mexico, even in natural protected areas. We compiled a checklist and determined ß-diversity indexes of amphibians and reptiles of the highly disturbed protected area, La Malinche National Park (LMNP) in Mexico, to determine the principal habitats for herpetofaunal conservation. After our extensive eight-year field sampling, we documented 28 species (nine amphibians and 19 reptiles), representing 11 families and 18 genera; four of these species are new records for LMNP. Of the species, 89% are endemic to Mexico. The IUCN Red List considers 22 species as Least Concern, one as Near Threatened, and four as Vulnerable. Meanwhile, the Environmental Viability Scores categorize three species as low vulnerability, 15 as medium, and 10 as high. According to the Mexican list of protected species, eight species are under Special Protection and nine are considered Vulnerable. The dissimilarity index between habitat types (ßsør) in both groups is high, principally due to the environmental gradient generated by the altitudinal range. Abies and Pine forest are high diversity areas for amphibians and reptiles, respectively, and must be considered for special protection. LMNP hosts more than 60% of the herpetofauna of Tlaxcala and is the principal "conservation island" for this state. Therefore, based on the percentage of state species represented, endemism and the current social and ecological problems, additional efforts that involve the local communities to protect the biodiversity of this National Park are necessary.

A new rare species of the Rhadinaeadecorata group from the Sierra Madre del Sur of Guerrero, Mexico (Squamata, Colubridae).

A new species of the Rhadinaeadecorata group is described based on two specimens from the Sierra Madre del Sur, Guerrero, Mexico. The new species differs from all other members of the genus Rhadinaea by having: eight supralabials; 149-151 (male) ventrals; 63-77 (male) subcaudals; two large pale nuchal blotches, forming an incomplete collar that occupies two scales laterally and is bissected along the dorsal midline; a postocular pale marking consisting of a well-defined, narrow line beginning behind the upper posterior margin of the eye and extending posteriorly nearly horizontally until connecting with the nuchal blotches; and the dark ground color of the flanks extending to the lateral portion of the ventrals. The large nuchal blotches distinguish the new species from the other members of the R.decorata group, except for R.cuneata and some individuals of R.hesperia (pale nuchal marking one-scale wide in R.marcellae, absent in the other species). The condition of the postocular pale marking distinguishes it from R.cuneata and R.hesperia (postocular pale marking wedge-shaped in R.cuneata, not connected with the pale post-cephalic markings in R.hesperia). Furthermore, the number of subcaudals and the coloration of the lateral portion of the ventrals distinguish it from R.omiltemana and R.taeniata, the remaining congeners found in Guerrero (85-90 in males of R.omiltemana and 91-121 in R.taeniata; dark color of the flanks not reaching ventrals in the former species, occasionally and faintly in R.taeniata). Additionally, a new combination for R.stadelmani is proposed. The new species is the first described in the genus Rhadinaea in more than 40 years.

A new species of Plestiodon (Squamata: Scincidae) from the Balsas Basin, Mexico.

We describe a new species of Plestiodon in the P. brevirostris group from the Balsas Basin in central Mexico. It is distinguished from the other species in the group by the following combination of traits: supraoculars four; interparietal enclosed posteriorly by parietals; primary temporal present; seventh supralabial usually contacting upper secondary temporal; longitudinal dorsal scale rows around midbody 23-26; Toe-IV lamellae 13-15; limbs not overlapping when adpressed against body; dorsolateral light line extending posteriorly to level of posterior end of anterior fourth of body or beyond; light median line absent in all growth stages; primary lateral dark lines separated medially by six dorsal scale rows and upper half of adjacent row on each side at level of midbody; lower secondary dark line faint at level of neck; and light coloration of supralabials extending ventrally to lip border. Analyses based on DNA sequences of three loci support the distinctiveness of the new species, as well as its sister species relationship with P. ochoterenae. The Environmental Vulnerability Score of the new species places it in the high vulnerability category.