A workforce of cave divers and scientists have uncovered a brand new cache of extinct monkey fossils submerged deep inside the underwater passages of a Caribbean cave.
Forty years in the past, just a few well-preserved stays of New World monkeys had been discovered on the Caribbean islands of Hispaniola and Jamaica, but it surely was sufficient to trace at a lacking patch of primate evolutionary historical past.
One in every of these fossil species was the Hispaniola monkey (Antillothrix bernensis), identified solely by way of an ankle bone and some bits of damaged jaw.
However with enhancements in cave diving security and expertise, researchers have probed deeper into the islands’ flooded cave programs since 2009, with the primary A. bernensis cranium present in 2011. These submarine caverns, vital to the indigenous Taíno folks, are studded with “remarkably well-preserved” fossils which have lain there for millennia, protected against the jostling of waves and animals.
The newest finds, out of the Cueva Macho cave system, on the Dominican Republic facet of Hispaniola, add new element to our understanding of the extinct species.
“The quantity and high quality of the Antillothrix crania outlined on this paper permit us to explain the cranium utterly and perceive variation between people,” says Johns Hopkins College paleobiologist Siobhán Cooke. “This will inform us concerning the food plan and social programs of those animals.”
4 new skulls had been discovered within the cave, together with three new mandibles. With these new items from the Cueva Macho system, in addition to an grownup mandible present in the same cave known as Padre Nuestro, the complete Antillothrix bernensis species is now represented by seven near-complete crania, two maxillae fragments, an occipital fragment, 5 full mandibles, and dozens of different non-skull bones.
It does not sound like a lot to go off, however this assortment – particularly the skulls – goes a great distance in describing the monkeys’ dimension, food plan, intercourse variations, even social lives. And that is extra element than we now have for some other Caribbean monkeys.
“These new specimens, together with these beforehand described, will permit for an in depth examine of population- and species-level variation, an exceedingly uncommon alternative for any fossil primate,” the authors write of their paper.
By analyzing the fossils, the researchers estimate that men and women had been of the same dimension, as much as 3.4 kilograms (round 7 kilos), which suggests mating wasn’t overly aggressive, and that they might have lived in small monogamous household teams with younger relying on their mother and father.
Their rounded enamel, with small canines, would have suited a food plan of fruit, just like the fashionable South American titi monkeys, which have comparable bodily options. They usually seem to have had no knowledge enamel, which is uncommon amongst primates.
It is a thriller how these monkeys received contained in the caves all these years in the past, however primarily based on injury to the jaw fossils, Cooke suspects it was not by alternative.
“It may very well be attainable {that a} now extinct owl, which might have been fairly giant, caught these monkeys and introduced them into the cave the place it was residing –rather than the monkeys falling in at random,” she says. “Owl feeding deposits usually are not unusual in Hispaniolan caves.”
The Hispaniola monkey grew to become extinct inside the final 10,000 years, but it surely’s unclear simply what drove this species below.
“These fossils assist us to higher perceive the anatomy of Antillothrix, which may help us establish ecological components which may have predisposed it to extinction… [and] finally information coverage for preserving the remaining mammalian range on the Caribbean islands and elsewhere ” says Cooke.
This analysis was printed in Journal of Human Evolution.