Secret History
The Clovis people were leading candidates for the title of first Americans. But a hoard of tools newly uncovered in Texas suggests the land was inhabited several thousand years before the reign of the Clovis culture.
When the people who built the Texan tools migrated, ice sheets would have made travel by land difficult. This lends strength to the hypothesis that the Americas were colonised by sea, not land.
Who the first Americans were, where they came from and when they arrived are contested issues among archaeologists. One favoured theory, known as "Clovis first", says that during the last Ice Age, people from Asia followed herd animals across a land bridge connecting Siberia to Alaska and established the first settlements in North America. The Clovis culture is characterised by pointed stone tools.
But recent finds of artefacts that pre-date the Clovis, including this new one in Texas, have challenged the Clovis-first hypothesis.
And maybe giving Uncle Wiggily a second thought, too.
The giant rabbit - technically termed Nuralagus rex - apparently lived between 3 million and 5 million years ago on the island of Micorca in the Mediterranean Sea. Fossils indicate the creatures had brittle backbones that made it impossible for them to hop, and likely weighed more than 25 pounds.
"N. rex was a very robust and peculiar rabbit," project leader Josep Quintana told Discovery News. "Surely he was a very calm and peaceful animal that moved with slow, but powerful, movements."
The rabbit was isolated on the island with just a few other species, including a type of bat, a dormouse and a giant tortoise. Because it didn't have any enemies, the rabbits' eye sockets and ears reduced over time.
New claims that Leonardo da Vinci's The Last Supper contains a hidden image of a woman holding a child are provoking a storm of interest on the internet.
The figure allegedly appears when the 15th Century mural painting is superimposed with its mirror image, and both are made partially transparent.
According to Slavisa Pesci, an Italian amateur scholar, the resulting composite picture shows a figure clutching what appears to be a young child.
More cynical observers may conclude that the double-image is far too blurry and faded to draw such conclusions.
Mr Pesci, who revealed his "findings" last week, chose not to speculate on who the child could be, but internet conspiracy theorists have been quick to point out similarities to the plot of the bestseller The Da Vinci Code, in which Jesus married his follower, Mary Magdelene.
Leonardo da Vinci websites received millions of hits within hours of Mr Pesci's announcement, and at least four - www.leonardodavinci.tv, www.codicedavinci.tv, www.cenacolo.biz and www.leonardo2007.com - were still down this morning due to the weight of traffic.
Mr Pesci also claims that the superimposed image shows a goblet in front of Jesus Christ - perhaps a depiction of his blessing of bread and wine - and transforms two of the people sitting at the table into knights.

A mysterious sculpture held by Montreal's Concordia University -- an artifact possibly thousands of years old and thought to pre-date the Pyramids of Egypt -- is being publicly displayed for the first time in hopes of attracting international attention and fresh insights into its origins.
The hitch, he acknowledges, is that no expert among the many consulted over the past decade can identify the sculpture's age or artistic tradition, nor can they decipher the "ancient, yet unidentifiable language" etched into the artwork.
One of the most enduring legends of Roman Britain concerns the disappearance of the Ninth Legion.
The theory that 5,000 of Rome's finest soldiers were lost in the swirling mists of Caledonia, as they marched north to put down a rebellion, forms the basis of a new film, The Eagle, but how much of it is true?
It is easy to understand the appeal of stories surrounding the loss of the Roman Ninth Legion - a disadvantaged band of British warriors inflicting a humiliating defeat upon a well-trained, heavily-armoured professional army.
It's the ultimate triumph of the underdog - an unlikely tale of victory against the odds. Recently, however, the story has seeped further into the national consciousness of both England and Scotland.
A survey of 141 archaeological sites in Europe found no evidence of habitual use of fire prior to about 400,000 years ago. Early humans arrived much earlier. Some archeological evidence indicates they arrived in southern Europe more than a million years ago, and the Happisburgh site in the northeastern part of England's Norfolk region contains stone tools dating back more than 800,000 years ago.
Evidence for the use of fire - concentrations of ashes and charcoal, sediments reddened by heat, rocks scarred by heat and burned bones - is nonexistent in Europe until around 400,000 years ago, write the researchers Wil Roebroeks of Leiden University in The Netherlands and Paola Villa of the University of Colorado Museum in Boulder.

Ötzi, the 5,300-year-old mummy from the Alps has a new face thanks to two reconstruction artists.
The South Tyrol Museum of Archaeology commissioned two reconstruction artists, Dutch brothers Adrie and Alfons Kennis, to recreate the mummy's face using both art and forensic science, including three-dimensional images of his skull. [Images of Iceman's reconstruction]
The finished face reveals a man with deep-set eyes, a long nose, weathered skin and hair that appears to be on its way to dreads.
Ötzi was discovered in 1991 by hikers in the Ötztal Alps along the Austrian-Italian border. Since then, researchers have mined his remains, the artifacts buried with him and his burial site for clues about his life (he lived sometime between 3350 and 3100 B.C.), death and descendants.
Governed by India, the archipelago separates the Bay of Bengal from the Andaman Sea. The islands are home to several hunter-gatherer tribes who until fairly recently have had very little contact with the outside world.
Anthropologists initially feared the tribes could have been completely wiped out. But Indian Air Force pilots flying sorties over the islands days after the tsunami reported seeing men who fired arrows at their helicopters. Since then there have been reports that the islanders used their ancient knowledge of nature to escape the tsunami.
Bernice Notenboom, president of Moki Treks, a travel company specializing in indigenous cultural tourism, is one of the few outsiders to have visited the tribes. She tells National Geographic of her impressions from her visit in April 2003.
"This is the power of tsunamis," head researcher Richard Freund told Reuters.
"It is just so hard to understand that it can wipe out 60 miles inland, and that's pretty much what we're talking about," said Freund, a University of Hartford, Connecticut, professor who lead an international team searching for the true site of Atlantis.
To solve the age-old mystery, the team used a satellite photo of a suspected submerged city to find the site just north of Cadiz, Spain. There, buried in the vast marshlands of the Dona Ana Park, they believe that they pinpointed the ancient, multi-ringed dominion known as Atlantis.
The team of archeologists and geologists in 2009 and 2010 used a combination of deep-ground radar, digital mapping, and underwater technology to survey the site.
Freund's discovery in central Spain of a strange series of "memorial cities," built in Atlantis' image by its refugees after the city's likely destruction by a tsunami, gave researchers added proof and confidence, he said.
Atlantis residents who did not perish in the tsunami fled inland and built new cities there, he added.
Research findings published in the March 11 edition of the journal Science by an international team of noted anthropologists, including several from Arizona State University, who study hunter-gatherer societies, are informing the issue by suggesting that human ancestral social structure may be the root of cumulative culture and cooperation and, ultimately, human uniqueness.
Because humans lived as hunter-gatherers for 95 percent of their species' history, current foraging societies provide the best window for viewing human social evolution, according to the authors. Given that, the researchers focused on co-residence patterns among more than 5,000 individuals from 32 present-day foraging societies around the globe, including the Gunwinggu, Labrador Inuit, Mbuti, Apache, Aka, Ache, Agta and Vedda. Their findings identify human hunter-gatherer group structure as unique among primates.