Way up in the Peruvian Andes, the title of the world’s highest altitude reptile was taken by a lizard. The lizard was found to be as high as 5,400 meters high, exposed to frigid temperatures, strong ultraviolet radiation, and low oxygen, according to researchers in Herpetozoa on February 15.
Zoologist José Cerdeña and colleagues climbed Peru’s Chachani volcano in October 2020, which is 6,057 meters above sea level. The team looked for lizards from Liolaemus, also known as tree iguanas, and discovered them as the researchers climbed over 5,000 meters. We’ve seen something moving between the rocks,’ says Cerdeña, of Saint Augustine National University in Arequipa, Peru. “We thought they were mice at first.”
He and his team saw, after having a closer look, that the darting animals were probably lizards, tentatively known as Liolaemus tacnae. The species is known to live in areas of high altitude in Peru, and at least one population has previously been spotted some 4,000 meters above sea level near Chachani. Survival is difficult enough for mammals under such prohibitive circumstances.
But cold-blooded reptiles face additional barriers to temperature control, so reports of reptiles this large are unusual. Until now, a cold-hardy species of toad-headed agama lizard (Phrynocephalus erythrurus) living at 5,300 meters on the Tibetan plateau was the highest living reptile. The Lizard of the Andes breaks the old record by 100 meters.
That the record goes to a Liolaemus lizard species is somewhat apt. With more than 270 species adapted to a wide variety of environments all over South America, the genus is extraordinarily diverse. As cooler temperatures have retreated to mountain peaks in the face of warming, climate change may have encouraged the status of Liolaemus as a record holder, Cerdeña says.
It is likely that this lizard species has recently started colonizing this altitude,” he says.” The next steps for the study group are to check the lizard’s identity with physical and genetic analysis, Cerdeña says. He also wants to know more about the physiology of the reptile, which could hold clues to its lifestyle at high altitudes.