150-year-old ‘mystery’ over desert lizard’s identity solved

ZSI researchers Sumidh Ray and Dr. Pratyush P. Mohapatra have designated a single specimen—ZSI-R-5050, housed in Kolkata—as the “lectotype,” or the defining representative of the species.

“Stoliczka, the then director of the Geological Survey of India, led an expedition to Persia and deposited numerous specimens in the Indian Museum which is now in with ZSI.,” said Dr. Mohapatra while speaking with The Indian Express.

“Over time, confusion arose regarding the species’ identity. This study confirmed that the oldest specimen, collected by Stoliczka, was indeed the original, leading to its official designation as Mesalina watsonana, previously known as Eremias watsonana,” he added.

First known as Eremias watsonana, the lizard is found across arid regions of South and Central Asia. The designation of the lectotype gives researchers a stable and globally accepted point of reference for future taxonomic and ecological studies. The newly clarified identity of Mesalina watsonana is expected to aid studies on desert biodiversity and lizard evolution across Asia.

ZSI Director Dr. Dhriti Banerjee, said, “Stoliczka’s collections remain crucial for understanding reptile taxonomy in the region. Clarifying these names isn’t just good science—it also honors the legacy of past researchers.”

The move ends decades of confusion among herpetologists, who had long grappled with scattered and poorly documented specimens kept across museums in Kolkata, London, and Vienna.

(Sharadiya Mitra is an intern at the Kolkata office of The Indian Express)