A New Subspecies of Lizard, Cnemidophorus sacki, from Michoacán, México

A careful field investigation in the Tepalcatepec Valley of Michoacán brings to light a distinct group of whiptail lizards that had slipped through earlier surveys of the region. By comparing dozens of preserved specimens with those from neighboring basins, the author shows that these lizards occupy a middle zone between two previously recognized populations. The study fills a geographical gap and offers fresh insight into how subtle environmental differences can shape reptile diversity.

The newly recognized subspecies stands out for its relatively large size—males exceed 130 mm in snout‑vent length—and for a characteristic array of dorsal scales and femoral pores. Its coloration is equally striking, with a pattern of fused light‑green rows, pink throats marked by a blue spot, and a mix of dust‑brown, bluish‑gray, and orange‑brown tones across the body and tail. In honor of a leading expert on the genus, the author proposes the name Cnemidophorus sacki zweifeli for this population, underscoring its unique place within the broader family of Mexican whiptails.