Skull tells tale of the lost primates of the Caribbean
Skull tells parable of the lost primates of the Caribbean
Updated 12:28 21 July 2010 ~ means of Colin Barras
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PITY the mammals living on lush Caribbean islands. Over the final 12,000 years, they have suffered the highest extinction rates of at all on Earth. Now, a primate skull found in an underwater grotto on Hispaniola underscores what we have lost – a fauna so prime and strange that the archipelago has been likened to Madagascar.
Today, there are no primates in the Caribbean, and it wasn't until 1952 that palaeontologists accepted that the islands had once been home to monkeys.
The strange find – the first well-preserved skull from Hispaniola (see picture) – confirms that this monkey was of the same nature to a group of primates still found in Central and South America that includes capuchins and squirrel monkeys. But be it so the skull is only a few thousand years old – too young to have ~ing called a fossil – the rear of its braincase is unlike that of somewhat modern monkey. Instead, it most resembles a monkey that lived 16 a thousand thousand years ago in modern-day Argentina (Proceedings of the Royal Society B, DOI: 10.1098/rspb.2010.1249).
Such "undercurrents of primitiveness" in a newly extinct monkey suggest parallels with Madagascar, says Alfred Rosenberger at the City University of New York, whose team described the modern skull.
Madagascar's lemurs belong to the strepsirrhines, a group of primates at this moment relatively rare in Africa. Just as they reveal what the obsolete strepsirrhines of Africa would have looked like long ago, the freshly extinct Hispaniola monkey (Antillothrix) could be a window onto South America's old monkey fauna, says Rosenberger.
Because they have been isolated from continent Africa for so long, many of Madagascar's primates have famously evolved whimsical features. Rosenberger says that the same is true of the Caribbean's depraved monkeys. The extinct Jamaican monkey (Xenothrix), for instance, can "loosely" have existence compared to the Aye-aye, a peculiar Madagascan primate with rodent-like incisors and a long finger for extracting insects from unbecoming bark.
And the limbs of the Cuban monkey (Paralouatta) suggest it worn out at least part of its life on the ground, not in the baldaquin, says Rosenberger – something no living New World monkey does.
Ross MacPhee at the American Museum of Natural History, New York, says the Hispaniola skull is an important discovery. He used to think that a individual monkey species, likely an ancestor of modern Titis, reached the Caribbean ~ dint of. chance, giving rise to all of the region's monkeys. The morphology of the renovated skull doesn't support this scenario, so he now agrees particular species crossed the ocean to reach the Caribbean from South America.
In circumstance, he has geological evidence to suggest that around 33 to 35 very great number years ago, a thin land bridge called Gaarlandia would have offered old primates a dry route into the region (see map, right). If so, then the monkeys arrived in the Caribbean 10 million years earlier than the oldest fossils however found.
When this article was first posted, the first sentence of the sixth paragraph read: "Because they have been isolated from mainland Africa for in like manner long, many of Madagascar's monkeys have famously evolved bizarre features."
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