The novel's third epigraph is from the The Yuma Daily Sun and refers to the discovery of a primate or early hominid skull (given the name Bodo by the team of archaeologists) displaying evidence of having been mutilated. Actually some 500,000 years old, it is not technically an example of scalping since the markings left on the skull suggest the entire flesh of the skull had been removed.
More information on Bodo can be found on the forum page at cormacmccarthy.com, which includes a contribution from Tim D. White himself, as well as a link to the original Yuma article. Click here.
With regards to scalping itself (the excision of the scalp and attached hair of an enemy for display, exchange, or torture), it is doubtful whether the practice goes as far back as this; but it does have a long history. In the Old World, Herodotus recorded scalping by ancient Scythians in central Asia; since backed up by the discovery of skulls with marks suggesting scalping at Scythian sites. Evidence indicates Europeans were scalping from the Stone Age till as late as 1036 in England.
Scalping in the Americas has equally old roots. Since 1940 archaeologists have discovered hundreds of pre-Columbian skulls with scalping marks at North American sites ranging from Georgia to Arizona to the Dakotas. A few predate even the abortive Viking explorations. Many of the skulls come from a single site in South Dakota where almost 500 people were massacred and scalped around 1325 AD. At least one instance of pre-Columbian artwork depicts a warrior toting scalps.
Despite such evidence, it became briefly fashionable in the 1960s and ‘70s for some to argue that Europeans were responsible for importing scalping to the Americas. It is clear, though, that the practice was widespread throughout the New World long before the 15th century arrival of the Spanish. However, the subsequent introduction of horses, metal knives, and guns, combined with territorial pressures, probably did lead to an increase in warfare and scalping. Further, it was only after white settlers began to offer bounties for scalps that the practice came to its fullest flowering. Though the Spanish in Mexico had earlier offered head bounties, New Englanders were apparently the first to grasp the usefulness of scalps as proof of death. In 1637 they began paying their Indian allies for either the heads of their Pequot enemies or, when the return distance was too great, the scalps. New Englanders were also first to pay whites for Indian scalps around 1675-76.