Rock art that is 12,000 years old depicts humans living while massive animals did, CNN reported. Archaeologists found the collection of paintings in the Amazon, in what is now central Colombia. The cause of the animals’ disappearance is still debated.
According to CNN, scientists recently made an exciting discovery of primitive artwork in the Amazon. “Archaeologists found paintings showing humans living with mastodons and other giant animals,” the video said. “Researchers say the images were likely painted around 12,600 to 11,800 years ago. The paintings are located on rock walls in what is now central Colombia in the Amazon rainforest.”
Mammoths and mastodons, two of the megafauna of the Pleistocene epoch, died out not long after the rock wall paintings were made. However, even though humans have discovered why dinosaurs died out 65 million years ago, the reason for the mammoths’ and mastodons’ much more recent extinctions is still a matter of debate.
A Lush Landscape of Megafauna
Mammoths and mastodons certainly weren’t alone as creatures of unusually large size during the Pleistocene. Many megafauna, or any animals that weigh more than 100 lbs., roamed the land, even if we don’t count humans for a moment.
“Sharing the Pleistocene landscape were creatures like the giant sloth, Megatherium, weighing up to 4.4 tons and 20 feet from head to tail; a North American camel, Camelops, that stood seven feet at the shoulder; giant beavers up to 7.2 feet long; the fantastic armored Glyptotherium, a relative of the armadillo over six feet long and weighing over a ton; and the North American bison who, thankfully, we still have with us today,” said Dr. Stuart Sutherland, Professor in the Department of Earth, Ocean, and Atmospheric Sciences at The University of British Columbia.
Large herbivores like these suggest predators of the same size, which have also been found. Dr. Sutherland mentioned the short-faced bear, which may have stood 12 feet tall; dire wolves, which are the same size as modern wolves but more muscular; a scavenger and possibly active predator bird, Teratornis, which had a 12-foot wingspan; the American lion, which was 25% larger than modern African lions; and the ever-popular sabretooth tiger.
So where did they all go?
Big Animals, Big Mystery
The first theory of megafauna extinction is that they were hunted out. Dr. Sutherland said that scientists have discovered a general “continent by continent extinction of megafauna” that coincides with the spreading of humans across the globe. However, despite archaeological evidence of some butchery of these creatures, many scientists question if early humans could have wiped out such large numbers of animals.
Climate change is another popular theory. “Following the glacial advance during the Ice Age, there are often associated extinctions of species possibly related to changes in vegetation patterns, as the climate warmed during an interglacial,” Dr. Sutherland said.
The final two theories are less popular, but still interesting. One involves a sort of hyper-disease that could’ve killed off a multitude of creatures, though it’s hard to imagine an illness that would transmit across—and affect—so many species. The final theory, Dr. Sutherland said, is “an extraterrestrial impact event that caused wildfires, and ultimately a global cooling event during a period called the Younger Dryas between 12,900 and 11,700 before the present day.”
The first two hypotheses combined also make a compelling argument. Climate change could have reduced the megafauna populations to a point that hunting finished them off. However, for now, it ultimately remains a mystery as large as the creatures themselves.
Dr. Stuart Sutherland contributed to this article. Dr. Sutherland is a Professor in the Department of Earth, Ocean and Atmospheric Sciences at The University of British Columbia (UBC). Raised in the United Kingdom, he earned an undergraduate degree in geology from the University of Plymouth and a PhD in Geological Sciences from the University of Leicester, for his studies on Silurian microfossils called chitinozoa.