A team led by Blair Hedges, a professor of biology at Penn State University, discovered and named the 24 species of lizards known as skinks, an article in the journal Zootaxa reported.
"Now, one of the smallest groups of lizards in this region of the world has become one of the largest groups," Hedges said. "We were completely surprised to find what amounts to a new fauna, with co-occurring species and different ecological types."
These New World skinks arrived in the Americas about 18 million years ago from Africa by floating on mats of vegetation, he said.
Though long established in the Caribbean, almost all of the identified species now face extinction, Hedges said, primarily to predation by the mongoose -- an invasive predatory mammal introduced by farmers to control rats in sugarcane fields during the late nineteenth century.
"The mongoose is the predator we believe is responsible for many of the species' close-to-extinction status in the Caribbean," Hedges said. "Our data show that the mongoose, which was introduced from India in 1872 and spread around the islands over the next three decades, has nearly exterminated this entire reptile fauna, which had gone largely unnoticed by scientists and conservationists until now."
A sharp decline in skink populations coincided with the introduction of the mongoose, he said.
"By 1900, less than 50 percent of those mongoose islands still had their skinks, and the loss has continued to this day," Hedges said.