Zoologists and biologists love it when an animal turns up where it wasn’t expected to. Either some incredible migration event has happened – perhaps involving a prison break – or a new species has been discovered.
In the case of the latter, the newfound species can sometimes look a little like one of its evolutionary cousins. Writing in The American Naturalist, a University of Toronto (UT)-led team describes a new discovery of its own, but in this case, the brand new lizard looks almost identical to another one found far away, despite the fact that both are entirely different species.
This chameleon-like lizard, Anolis landestoyi, was first spotted and photographed on the island of Hispaniola, a strip of territory shared by Haiti and the Dominican Republic. At first glance, it appeared to be the same type of lizard found in Cuba, the Anolis porcus. “Our immediate thought was that this looks like something that's supposed to be in Cuba, not in Hispaniola,” Luke Mahler, the study’s lead author and an assistant professor of evolution and ecology at UT, said in a statement.
After one was captured by naturalist Miguel Landestoy, he sent clear photographs of it to UT researchers. They noted that it was slightly morphologically different to its Cuban cousin, meaning that it was indeed a separate species of lizard. “I always wanted to describe a new species,” Mahler added. “Doing so is the fulfillment of a dream I've had since I was a little kid.”
As it turns out, these types of lizard – Greater Antillean anoles – are found all across these islands. They are a classic example of something known as replicated adaptive radiation, wherein related species evolving on different islands eventually speciate into similar species with similar morphologies, in order to occupy similar ecological niches. They are known as “ecomorphs.”
Image in text: The Cuban anole (pictured) looks incredibly similar to the Hispaniolan one. Miguel Landestoy
Most Great Antillean anoles actually have a matching counterpart on another island, although about a fifth currently do not. This new discovery strikes another off that increasingly small list.
The newly discovered A. landestoyi, like its Cuban cousin, resemble chameleons rather than typical anoles in that they’re rather huge, slow-moving, and favor clinging on to moss- or lichen-coated branches high up in the canopy of the forest.
As for how this species evolved, there are two options: The first is that A. landestoyi has a shared ancestry with the Cuban A. porcus, whose predecessor migrated to Hispaniola from Cuba. The second option is that this is a case of convergent evolution, wherein distally related organisms evolve the same adaptations in different environments. Either way, species across these islands are more similar than the team previously thought.
Sadly, despite being a newly identified species, it is already in considerable trouble. It occupies a habitat that is experiencing overzealous deforestation, and time is running out to save it from certain extinction.
The diversity of lizards on these islands is incredible. Pictured here is a green iguana. anekoho/Shutterstock