Effective range of radiocarbon dating
By Gisela Crespo, CNN, April 26, 2017 The remains of a mastodon discovered during a routine excavation in California shows possible human activity in North America 130,000 years ago -- or about 115,000 years earlier than previously thought.Paleontologists with the San Diego Natural History Museum discovered the remains of the elephant-like animal more than 20 years ago.Evidence that they existed in the Southern Hemisphere has been mounting.
But the Buitreraptor fossil in South America, which dates back 90 million years and closely resembles fossils from the North, means one of two things: Either dromaeosaurs existed when Pangea was intact; or the newfound Buitreraptor and its northern look-alikes evolved separately yet with remarkably similar results.
The scientists say they found what appear to be hammerstones and stone anvils at the site, showing that ancient humans had the manual skill and knowledge to use stone tools to extract the animal's Bone Marrow and possibly to use its bones to make tools.
The site was named Cerutti Mastodon site, in honor of Richard Cerutti, who made the discovery and led the excavation.
It has a long head and long tail and wing-like forelimbs.
Its serrated teeth, like steak knives, suggest it was a carnivore.