Most geneticists agree that Native Americans are descended from Siberians who crossed into America 26,000 to 18,000 years ago via a land bridge over the Bering Strait. But while genetic analysis of modern Native Americans lends support to this idea, strong fossil evidence has been lacking.
Now a nearly complete skeleton of a prehistoric teenage girl, newly discovered in an underwater cave in the Yucatán Peninsula, establishes a clear link between the ancient and modern peoples, scientists say.
First of their kind scans of preserved infant woolly mammoths have made the insight into the early stages of development for the 40,000 year-old prehistoric animals less fuzzy.
According to a report published July 8 in the Journal of Paleontology, researchers performed a full body CT scan of two mammoth newborns, named Lyuba and Khroma, who died at the ages of 1 and 2 months respectively. The skeletal structures of the infants, which researchers consider to be the most well-preserved baby mammoth specimens found to date, gave the scientists the chance to document the various changes that occurred to the body as the ancient pachyderms grew. They also helped determine whether the mammoth gestation periods may have been shorter than that of modern elephants.