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

Abstract

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.

Mitochondrial DNA sequences and nuclear microsatellites reveal population genetic structure of the range-restricted hummingbirdPhaeoptila sordidain the Balsas Basin

“…The Balsas Depression biotic province, a wide, and disjunct area of SDTDF occupying the Río Balsas Depression (Rzedowski 1978, Morrone 2014, Pavón-Vázquez et al 2017), is one of the most important hotspots for endemism (Sousa and Delgado-Salinas 1993, García-Trejo and Navarro-Sigüenza 2004, Becerra and Venable 2008, Navarro-Sigüenza et al 2014) in which species represent old or recent elements of the Mexican flora (Sousa and Soto 1987, Sotuyo et al 2007, Ramírez-Arriaga et al 2014). The Río Balsas Depression is an east-west oriented basin that forms the lowlands of the Balsas River drainage basin surrounded by mountains, some of which exceed 2,000 m above see level and have a horizon that extends towards the east of the Tehuacán-Cuicatlán Valley and Valles Centrales in Puebla and Oaxaca states.…”