International conservation charity ZSL (Zoological Society of London) has today announced that analysis of bones from an extinct monkey species found in Jamaica reveal it experienced an extraordinary evolution.
The mysterious monkey – named Xenothrix – was discovered by teams from ZSL, London’s Natural History Museum and the American Museum of Natural History in New York who found the new species to be very different to any living monkey.
The new discovery was in fact most closely related to South America’s titi monkeys (Callicebinae) and probably found its way overwater to Jamaica on floating vegetation around 11 million years ago. It is believed that many other animals, such as large Caribbean rodents called hutias, colonised the region in the same way.
Examination of ancient DNA also revealed how the unusual ecology of the islands dramatically influenced evolutionary change as it appears the Xenothrix was a slow-moving tree-dweller with relatively few teeth, and leg bones like a rodent’s.
Professor Samuel Turvey from ZSL, a co-author on the paper, said: “This new understanding of the evolutionary history of Xenothrix shows that evolution can take unexpected paths when animals colonise islands and are exposed to new environments. However, the extinction of Xenothrix, which evolved on an island without any native mammal predators, highlights the great vulnerability of unique island biodiversity in the face of human impacts”.
Professor Ian Barnes, whom runs the NHM’s ancient DNA lab, and co-author said: “Recovering DNA from the bones of extinct animals has become increasingly commonplace in the last few years. However, it’s still difficult with tropical specimens, where the temperature and humidity destroy DNA very quickly. I’m delighted that we’ve been able to extract DNA from these samples and resolve the complex history of the primates of the Caribbean.”
Ross MacPhee of the American Museum of Natural History’s Mammalogy Department, a co-author of the study, said: “Ancient DNA indicates that the Jamaican monkey is really just a titi monkey with some unusual morphological features, not a wholly distinct branch of New World monkey. Evolution can act in unexpected ways in island environments, producing miniature elephants, gigantic birds, and sloth-like primates. Such examples put a very different spin on the old cliché that ‘anatomy is destiny.’”
The Galapagos Islands are famous for inspiring Charles Darwin’s theory of evolution and the islands of the Caribbean have also been home to some of the most unusual and mysterious species to have ever evolved. However, the Caribbean has also experienced the world’s highest rate of mammal extinction since the end of the last ice age, probably caused by hunting and habitat loss by humans, and predation by invasive mammals brought by early settlers.
Main image – Red titi monkey (ZSL)