Extinct Sloth Fossils Discovered In Underwater Cave | National Geographic

[Music] We don't know how the sloths ended up in the cave. Our working hypothesis is that the sloth entered the cave in order to look for water, uh, and died in those positions. Then what happened was water level then rose, submerging the sloth remains, preserving them where they were found today.

The cave called Qu Margarita 1 is located in the province of Mananas in Western Cuba. There's lots of underwater caves and caverns that were formed when sea levels were lower during the last glacial period, um, and that became submerged when sea levels rose since that [Music] time.

So what was seen in the cave are some, uh, amazing paleontological remains. The remains of three extinct sloths. We're not really clear when they went extinct, but it was probably four or 5,000 years ago. In addition to the sloths, we've also identified a number of selms, which are cave deposits, um, that provide a very important record of ancient climate and also cave sediments as well, which we hope to recover that are going to give us information about the water level history of the cave.

This can, in turn, be linked to sea level changes and also climate change as well. Sloths went extinct in the Caribbean between 4 and 5,000 years ago, so we expect they're at least as old as that. They could be as, um, young as about 10,000 years.

One of our efforts has been to try and radiocarbon date the sloth remains, and unfortunately, we haven't had success with that so [Music] far. Underwater caves with extinct animal remains are extraordinarily rare. From this point of view, this is an extremely exciting opportunity to study questions related to paleontology and questions related to ancient climate and ancient [Music] environment.