Lost Giants: Did Mammoths Vanish Before, During and After Humans Arrived?

[Adsos Letter]

Three studies seem to disagree as to when mammoths, saber-toothed cats and other North American megafauna disappeared

Source: Scientific American
By Charles Q. Choi

Before humans arrived, the Americas were home to woolly mammoths, saber-toothed cats, giant ground sloths and other behemoths, an array of megafauna more impressive than even Africa boasts today. Researchers have advanced several theories to explain what did them in and when the event occurred. A series of discoveries announced in the past four weeks, at first glance apparently contradictory, adds fresh details to the mystery of this mass extinction.

One prominent theory pegs humans as the cause of the demise, often pointing to the Clovis people, who left the earliest clear signs of humans entering the New World roughly 13,500 years ago. The timing coincides with the disappearance of megafauna, suggesting the Clovis hunted the animals to extinction or infected them with deadly disease. Another hypothesis supposes that climate was the culprit: it had swung from cold to warm twice, including a 1,300-year-long chill known as the Younger Dryas; such abrupt shifts might have overwhelmed the creatures’ abilities to adapt.

To pin down when the megafauna vanished, paleoecologist Jacquelyn Gill of the University of Wisconsin–Madison and her colleagues analyzed fossil dung, pollen and charcoal from ancient lake sediments in Indiana. The dung of large herbivores harbors a fungus known as Sporomiella , and its amounts in the dung gives an estimate of how many mammoths and other megafauna were alive at different points in history. Pollen indicates vegetation levels, and charcoal signals how many fires burned; the extent of flora and wildfires is related to the presence of herbivores, the researchers say in the November 20 Science. Without megaherbivores to keep them in check, broad-leaved tree species such as black ash, elm and ironwood claimed the landscape; soon after, buildups of woody debris sparked a dramatic increase in wildfires. Putting these data together, Gill and her team conclude that the giant animals disappeared 14,800 to 13,700 years ago —up to 1,300 years before Clovis.

A different study, however, suggests that this mass extinction happened during Clovis. Zooarchaeologist J. Tyler Faith of George Washington University and archaeologist Todd Surovell of the University of Wyoming carbon-dated prehistoric North American mammal bones from 31 different genera (groups of species). They found that all of them seemed to meet their end simultaneously between 13,800 to 11,400 years ago, findings they detailed online November 23 in the Proceedings of the National Academy of Sciences USA.

Further discussion at the link: http://www.scientificamerican.com/article.cfm?id=lost-giants-did-mammoths&page=2

[tularetom]

1. I know very little about this subject

But I remember hearing a story about someone having discovered atlatl points among the bones of a mammoth skeleton so I've always assumed the critters were done in at least in part by the Clovis people.

[Adsos Letter]

2. I recall hearing that same thing tularetom; plus, Clovis points are often quite large

and seem designed for bringing down larger than our current examples of game (with the exception of bears and buffalo).

[tabatha]

3. I think there is more that will be coming out about this.

[ashling]

4. Yoda says: "There is only Before or after, there is no During"

once we were here, we were here.
:eyes: