Footprints found in New Mexico tell a story of how ancient humans chased and hunted giant sloths and how they possibly drove it to extinction.
A team of scientists from Bournemouth University in the UK discovered perfectly preserved giant ground sloth footprints in a lakeside located in what is now a part of the White Sands National Monument.
One of the interesting findings is that the sloths were taking generally straight or curved paths, but when human footprints came nearby, the sloths took sharp turns as evident in the "flailing circles" seen in the animal's footprints.
Inside the sloth's foot tracks were human footprints, which, according to the researchers, suggest that ancient humans were extending their stride up to 110 centimeters apart as opposed to the normal distance of about 60 centimeters.
The sloths, on the one hand, appeared like they used their sharp claws for defense.
"That's a radical change from just walking. [The sloths] were obviously reacting to something in their environment," said Anthony Martin, a vertebrate paleontologist at Emory University in Atlanta.
Humans Drove Sloths To Extinction
While it has long been an accepted theory that climate change and diseases are what drove certain animals to extinction, these latest findings published in Science Advances provide a new perspective.
Lead author Matthew Bennett explained it is possible that ancient humans armed with spears have chased and hunted sloths. He cited a historical fact that these humans have migrated to North America after crossing the bridge from Asia around 15,000 to 25,000 years ago.
"Understanding the ways in which our ancestors might have, and the fact that they did tackle big prey, is quite interesting because a big animal like this would have come with huge amounts of risk ... Therefore, what justifies that risk?" Bennett asked.
In future studies, Bennett said they will read the footprints to understand how humans tackled sloths. He added that the data will help determine "whether humans are guilty or not in that role of extinction."
Not everyone is convinced with Bennett's theory. Spencer Lucas, a paleontologist at the New Mexico Museum of Natural History and Science, said that sloths and humans could have been present in the same place at the same time without the purpose of hunting.
ReBecca Hunt-Foster explained it is difficult to determine what really transpired during that era because animals sometimes would make sharp turns even in the absence of prey.
Interpreting Fossilized Behaviors
Fossilized footprints tell the behaviors of its owners — something that scientists will not be able to interpret in fossilized bones. Aside from its rarity, Lucas said footprints are often overlooked at.
This new interpretation on how humans interacted with ancient animals offers vivid details of prehistoric living. Bennett likened the interaction to a dance of "life and death," but it is still a "lovely story" regardless.