The trek—from the North American desert to Fiji—now represents the longest known migration of any terrestrial animal.

There are 45 different species of Iguanidae in the Caribbean and the tropical, subtropical and desert areas of North, Central, and South America, including the marine iguanas of the Galapágos and the chuckwallas in the American Southwest.

But new research suggests that millions of years ago, iguanas pulled off the 5,000 mile (8,000 kilometer) odyssey on a raft of floating vegetation — masses of uprooted trees and small plants. That journey is thought to be a record — further than any other land-dwelling vertebrate has ever traveled on the ocean.